Q — ^^:: — m

Fishery Bulletin

■^'virES o* '^

JUN 1 1 1979

A

Woods Hole,

Vol. 77, No. 1

/

JanuaryTSTS

RICHARDSON, SALLY L., and WAYNE A, LAROCHE. Development and occur-
rence of larvae and juveniles of the rockfishes Se6astes crameri,Sebastes pinniger,
and Sebastes helvomaculatus (family Scorpaenidae) off Oregon 1

LEATHERWOOD, STEPHEN. Aerial survey of the bottlenosed dolphin, Tursiops
truncatus, and the West Indian manatee, Trichechus manatus, in the Indian and
Banana Rivers, Florida 47

MORGAN, STEVEN G., and ANTHONY J. PROVENZANO, JR. Development of
pelagic larvae and postlarva of Squilla empusa (Crustacea, Stomatopoda), with an
assessment of larval characters within the Squillidae 61

COHEN, DANIEL M., and JOSEPH L. RUSSO. Variation in the fourbeard rockling,
Enchelyopus cimbrius, a North Atlantic gadid fish, with comments on the genera of
rocklings 91

SUMIDA, B. Y., E. H. AHLSTROM, and H. G. MOSER. Early development of seven
flatfishes of the eastern North Pacific with heavily pigmented larvae (Pisces,
Pleuronectiformes) 105

GREENBLATT, PAUL R. Associations of tuna with flotsam in the eastern tropical
Pacific 147

HAYNES, EVAN. Description of larvae of the northern shrimp, Panda/as borealis,
reared in situ in Kachemak Bay, Alaska 157

TRICAS, TIMOTHY C. Relationships of the blue shark, Prionace glauca, and its
prey species near Santa Catalina Island, California 175

OMORI, MAKOTO, and DAVID GLUCK. Life history and vertical migration of the
pelagic shrimp Sergestes similis off the southern California coast 183

NEVES, RICHARD J., and LINDA DEPRES. The oceanic migration of American
shad, Alosa sapidissima, along the Atlantic coast 199

KENDALL, ARTHUR W., JR., and LIONEL A. WALFORD. Sources and distribu-
tion of bluefish, Pomatomus saltatrix, larvae and juveniles off the east coast of the
United States 213

WAHLE, ROY J., REINO O. KOSKI, and ROBERT Z. SMITH. Contribution of
1960-63 brood hatchery-reared sockeye salmon, Oncorhynchus nerka, to the Co-
lumbia River commercial fishery 229

MEYER, THOMAS L., RICHARD A. COOPER, and RICHARD W. LANGTON.
Relative abundance, behavior, and food habits of the American sand lance, Ammo-
dytes americanus, from the Gulf of Maine 243

(Continued on next page)

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Fishery Bulletin

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National Marine Fisheries Service National Marine Fisheries Service

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Fishery Bulletin

CONTENTS

Vol. 77, No. 1 January 1979

RICHARDSON, SALLY L., and WAYNE A. LAROCHE. Development and occur-
rence of larvae and juveniles of the rockfishes Se6as<es crameri,Sebastes pinniger,
and Sebastes helvomaculatus (family Scorpaenidae) off Oregon 1

LEATHERWOOD, STEPHEN. Aerial survey of the bottlenosed dolphin, Turswps
truncatus, and the West Indian manatee, Trichechus manatus, in the Indian and
Banana Rivers, Florida 47

MORGAN, STEVEN G., and ANTHONY J. PROVENZANO, JR. Development of
pelagic larvae and postlarva ofSquilla empusa (Crustacea, Stomatopoda), with an
assessment of larval characters within the Squillidae 61

COHEN, DANIEL M., and JOSEPH L. RUSSO. Variation in the fourbeard roekling,
Enchelyopus cimbrius, a North Atlantic gadid fish, with comments on the genera of
rocklings 91

SUMIDA, B. Y., E. H. AHLSTROM, and H. G. MOSER. Early development of seven
flatfishes of the eastern North Pacific with heavily pigmented larvae (Pisces,
Pleuronectiformes) 105

GREENBLATT, PAUL R. Associations of tuna with flotsam in the eastern tropical
Pacific 147

HAYNES, EVAN. Description of larvae of the northern shrimp, Pancfa/us borealis,
reared in situ in Kachemak Bay, Alaska 157

TRIG AS, TIMOTHY C. Relationships of the blue shark, Prionace glaiica. and its
prey species near Santa Catalina Island, California 175

OMORI, MAKOTO, and DAVID GLUCK. Life history and vertical migration of the
pelagic shrimp Sergestes simtlis off the southern California coast 183

NEVES, RICHARD J., and LINDA DEPRES. The oceanic migration of American
shad, Alosa sapidisstma, along the Atlantic coast 199

KENDALL, ARTHUR W., JR., and LIONEL A. WALFORD. Sources and distribu-
tion of hluehsh, Pomatomus saltatrix, larvae and juveniles off the east coast of the
United States 213

WAHLE, ROY J.. REINO O. KOSKI, and ROBERT Z. SMITH. Contribution of
1960-63 brood hatchery-reared sockeye salmon, Oncorhynchus nerka, to the Co-
lumbia River commercial fishery 229

MEYER, THOMAS L., RICHARD A. COOPER, and RICHARD W. LANGTON.
Relative abundance, behavior, and food habits of the American sand lance, Ammo-
dytes americanus, from the Gulf of Maine 243

(Continued on next page I

Seattle. Washington
1979

For sale by the Superintendent of Documi'ntji. U S Government PrintingOffice. Washington,
DC 20402 — Subscription price per year $12 00 domestic and $15 00 foreign Cost per single
issue: $3.00 domestic and $3 75 foreign

Contents-continued

OLLA, BORI L., ALLEN J. BEJDA. and A. DALE MARTIN. Seasonal dispersal and
habitat selection of cunner, Tautogolabrus adspersus . and young tautog, Tautoga
onitis. in Fire Island Inlet, Long Island, New York 255

HUGHES, STEVEN E., and GEORGE HIRSCHHORN. Biology of walleye pollock,
Theraga chalcogramma, in the western Gulf of Alaska, 1973-75 263

Notes

HOBSON, EDMUND S., and J AMES R. CHESS. Zooplankters that emerge from the

lagoon floor at night at Kure and Midway Atolls, Hawaii 275

WENZLOFF, D. R., R. A. GREIG, A. S. MERRILL, and J. W. ROPES. A survey of

heavy metals in the surf clam, Spisula soUdissima, and the ocean quahog, Arc/(ca

islandica. of the Mid-Atlantic coast of the United States 280

OVERHOLTZ, WILLIAM J., and JOHN R. NICOLAS. Apparent feeding by the fin

whale. Balaenoptera physalus. and the humpback whale, Megaptera novaengliae.

on the American sand lance, Ammodytes americaniis. in the northwest Atlantic . 285
WILLIAMS, JOHN G. Estimation of intertidal harvest of Dungeness crab. Cancer

magister, on Puget Sound, Washington, beaches 287

TARGETT, TIMOTHY E. A contribution to the biology of the puffers Sphoeroides

testudineus and Sphoeroides spengleri from Biscayne Bay, Florida 292

HUI, CLIFFORD A. Correlates of maturity in the common dolphin, Delphinus

delphis 295

ALLEN, LARRY G. Larval development ofGobiesox rhessodon (Gobiesocidae) with

notes on the larva oi Rimicola muscarum 300

BAILEY, KEVIN, and JEAN DUNN. Spring and summer foods of walleye pollock,

Theragra chalcogramma, in the eastern Bering Sea 304

DIETRICH, CHARLES S., JR. Fecundity of the Atlantic menhaden, Brevoortia

tyranniis ,308

LANDER, ROBERT H. Role of land and ocean mortality in yield of male Alaskan fur

seal, Callorhinus ursinus ,311

Notices
NOAA Technical Reports NMFS published during the last 6 mo of 1978 315

Vol. 76, No. 4 was published on 28 February 1979.

The National Marine Fisheries Service (NMFS) does not approve, rec-
ommend or endorse any proprietary product or proprietary material
mentioned in this publication. No reference shall be made to NMFS, or
to this publication furnished by NMFS, in any advertising or sales pro-
motion which would indicate or imply that NMFS approves, recommends
or endorses any proprietary product or proprietary material mentioned
herein, or which has as its purpose an intent to cause directly or indirectly
the advertised product to be used or purchased because of this NMFS
publication.

DEVELOPMENT AND OCCURRENCE OF LARVAE AND

JUVENILES OF THE ROCKFISHES SEBASTES CRAMERI,

SEBASTES PINNIGER, AND SEBASTES HELVOMACULATUS

(FAMILY SCORPAENIDAE) OFF OREGON'

Sali.y L. Rhhardson^ and Wayne A. Laroche^

ABSTRACT

Developmental series of larvae and juveniles of" three species of northeast Pacific rockfishes (Scor-
paenidae; Sebastes) are illustrated and described: iS. crarnen (8.0 to 130.5 mm standard length). S
pinniger (7.8 to 181 mm standard length), and S ht'luornaculatus (7.7 to 183 mm standard length). The
descriptions include a literature review, characters used for identification including meristics and
supraocular spine patterns, distinguishing features, general development, morphology, fin develop-
ment, spmation, scale formation, and pigmentation Occurrence in waters off Oregon is discussed.

The approach that was used Uy identify larval and juvenile specimens o( Sebastes from plankton,
midwater trawl, and bottom trawl collections from Oregon waters is presented, since 36 species
reportedly occur there. Developmental terminology is newly defined for Sebastes. Larval and juvenile
spination is presented schematically and defined.

Larvae and juveniles of the three species described here are compared with other known Sebastes
larvae and juveniles from the northeast Pacific

Data gathered during this study extend the southern range limit of Sebastes emphaeus to Punta
Gordo, Calif

Rockfish of the genus Sebastes are an important
group of fishes in the northeast Pacific both in
terms of number of species and in commercial and
sport fisheries. Sixty-nine species of Sebastes
occur between the Gulf of California and the Gulf
of Alaska (Chen 1971, 1975). In 1975, Pacific trawl
landings of Sebastes spp. in the United States and
Canada, categorized as "Pacific ocean perch" and
"other rockfish," were 17,400 metric tons (t) or
23.9% of the total trawl landings (Verhoeven
1976). In California, rockfish compose half the
number of sportfish caught (Young 1969).

"Pacific ocean perch" (primarily Sebastes
alutus) trawl landings in the United States and
Canada declined from a peak of 14,000 t in 1965 to
8,500 t in 1975 and "other rockfish" landings sub-
sequently increased from 8,600 t in 1965 to 16,300
t in 1973 and 13,300 t in 1975 (Pacific Marine
Fisheries Commission 1964-76; Verhoeven 1976).

'From a final report for NCAA NMFS Contract No. 03-6- 208-
35343 submitted to Northwest and Alaska Fisheries Center.
National Marine Fisheries Service, NOAA, 2725 Montlake
Boulevard East, Seattle, WA 98112. on 15 June 1977.

^School of Oceanography. Oregon State University. Corvallis.
Oreg.; present address: Gulf Coast Research Laboratory. P.O.
Drawer AG. Ocean Springs, MS 39564.

^School of Oceanography, Oregon State LIniversitv. Corvallis.
OR 97331.

Manu.scnpt accepted Augu.'it 197K

FISHERY BULLETIN: VOL. 77. NO. 1. 1979.

Because of this shift in composition of trawl land-
ings, knowledge of the biology of the individual
species involved, including their early life history,
is becoming increasingly important. Such infor-
mation is relatively scarce, partly because of the
difficulty involved in identifying the young stages.

Rockfish larvae, which are e.xtruded live from
ovoviviparous females, are pelagic as are young
juveniles. The pelagic larvae are very abundant,
ranking third or fourth in annual larval fish
abundance off California (Ahlstrom 1961, 1965)
and second only to osmerid larvae off Oregon
(Richardson 1977; Richardson and Pearcy 1977).
Juveniles are important as forage items for larger
fishes, such as albacore (Powell et al. 1952) and
salmon (Whitney 1893; Silliman 1941; Pritchard
and Tester 1944; Merkel 1957), and marine birds
(Follett and Ainley 1976).

Pelagic larvae and juveniles of relatively few of
the 69 northeast Pacific rockfish species have been
described. Illustrations or partial descriptions of
pigment patterns have been presented for preex-
trusion or newborn larvae of 47 of these species but
only 26 of these were reared to the point of yolk
absorption (Table 1). The first larval developmen-
tal series of Sebastes spp. were presented as two
unnamed .species (Ahlstrom 1965) the second of

1

FISHERY BULLETIN: VOL. 77. NO I

which is now known to be S. paucisplnix (Moser
1967; Moser et al. 1977). Complete development
series from newly hatched larvae to benthic
juveniles have only been described for S. cortezi, S.
jordani,S. levis,S. inacdonaldi,S. melanostomus,
S. paucuipinis. and Sebastes sp. — Gulf of Califor-
nia Type A (Moser 1967. 1972; Moser et al. 1977;
Moser and Ahl.strom 1978).

This paper is a contribution to the knowledge of
the early life history of northeast Pacific rock-
fishes. Developmental series of three species, S.
crameri, S. pinnigcr, and S. helvomaculalus. are
described for the first time. The first two species
are important contributors to Oregon trawl land-
ings (Niska 1976). Information on occurrence of
larvae and juveniles of these three species off Ore-
gon is also given. Because of the large species
complex oi Sebastes in the northeast Pacific and
the difficulty in identifying young rockfish, e.g.,
adult keys cannot be used, the approach that was
used to identify the specimens in this study is
presented as part of the methodology.

MATERIALS AND METHODS

Collections

Specimens described in this paper came from
collections in the School of Oceanography, Oregon
State University. The collections were obtained
with 70 cm bongo nets, neuston nets, meter nets,
Isaacs-Kidd midwater trawls, beam trawls, and
otter trawls off the Oregon coast since 1961 during
all months of the year. Samples were taken along
the entire coast, but were concentrated along an
east-west transect off Newport, Oreg. (lat.
44°39.1' N). All material had been preserved in
either 5 or 109^ Formalin'' and most had been
transferred to 30 or 40'7c isopropyl alcohol. Over
12,000 Sebastes larvae and juveniles were sorted
from the available collections.

Approach to Identification

Geographic ranges of all known northeast
Pacific species (excluding the new species being
described by Lea and Fitch (Chen 19751, presum-
ably from California] were recorded from the lit-
erature (Appendix Table 1). Additional range in-
formation gathered during this study extends the

^References to trade names does not imply endorsement by the
National Marine Fisheries Service. NOAA.

southern range of .S. emphaeus through Oregon to
Punta Gordo, Calif, (lat. 40°12.9' N, long.
124°23.7' W, depth 97 m). Adults of only 36 of
these species are reported to occur off Oregon. The
occurrence of two of these, S. eos and S. rosaceus, is
questionable north of northern California (Chen
19711. Although ocean currents could potentially
carry larvae and juveniles of additional species
into Oregon waters, it is unlikely that large num-
bers of young of other species would be taken in an
area where the adults do not occur. Following this
assumption, tables of morphological characters
were prepared for these 36 potential species. The
most useful characters for identifying young
rockfish were shape of the upper profile of the head
( interorbital space) and presence or absence of
specific head spines, particularly the supraocular
( Appendix Table 2 1; number, including range and
usual (most commonly occurring) number of dor-
sal fin rays, anal fin rays, and pectoral fin rays
(Appendix Table 3); total number of gill rakers on
the first gill arch (Appendix Table 4); number of
lateral line pores (Appendix Table 5); number of
diagonal scale rows below the lateral line (Appen-
dix Table 6). Proportions of body parts related to
standard length such as length of upper jaw, head
length, length of longest dorsal spine, and body
depth at pelvic fin insertion were compiled but
were not particularly useful. Additional informa-
tion which was sometimes helpful included rec-
ords from trawl surveys off Oregon (Demory et al.
1976) and commercial catch trends in Oregon
(Niska 1976) which gave indications of species
common in trawlable habitats in the area. Pig-
ment banding patterns of adults were also useful.

Initially, counts were made on each juvenile to
be identified along with notes on additional, po-
tentially useful characters. Data for each speci-
men were then screened through each of the ap-
pendix tables, and the species which did not agree
were eliminated as potential candidates. This ap-
proach, together with some additional data from
the literature as noted in the text, lead to positive
identification for the species included in this
paper.

Developmental series were established back-
wards from juveniles primarily on the basis of
pigmentation, particularly that of the pectoral
and pelvic fins and that on the dorsal and ventral
body margins, general body shape (e.g., short and
stubby, slender and elongate), and constancy in
number of dorsal, anal, and pectoral fin rays which
could be counted back to postflexion, sometimes

RICHARDSON and LAROCHE. DEVELOPMENT AND OCCURRENCE i iF ROCKFISHES

flexion, larvae. Developmental series could not be
carried back to newly extruded larvae in the
plankton samples with certainty. Pigmentation is
the primary character used to distinguish small
larvae prior to development of fin rays and head
spines. Pigment patterns of newborn larvae are
often similar among a number of species and these
patterns may change considerably by the time the
yolk is absorbed (Westrheim 1975: Moser et al.
1977). Preextrusion and newborn larvae have
been described for 29 of the 36 species o{ Sebastes
off Oregon, but larvae reared to yolk absorption
have only been described for 15 (Table 1). The
number of species which have patterns similar to
those that have been described is unknown. Rear-
ing larvae of the remaining species to yolk absoi-p-
tion will be necessary to provide an adequate
foundation for identification of small larvae in
plankton samples. We had no opportunity to rear
larvae from known parents.

Meristics"

Counts were made on unstained material as not
enough specimens were available to make com-
plete stained series for developmental ossification
studies. [One to several pelagic juveniles of S.
crameri , S. pinniger, and S. helvomaculatus were
stained with alizarin red S (Taylor 1967) for
examination of general bone structure, spination,
and secondary caudal rays.] Fin spines and rays
were only counted when they appeared to be fully
formed structures under magnification, which
may approximate initial ossification. Bases of fin
rays, visible prior to actual ray formation, were
not counted. In Sebastes , the 13th dorsal spine and
the 3d ana! spine form first as soft rays which then
transform to spines beginning at the basal portion
and continuing distally. These were considered to
be "prespines" until spine formation was com-
plete.

Counts were made of dorsal fin spines and rays,
anal fin spines and rays, pectoral fin rays, pelvic
fin rays, principal caudal fin rays, gill rakers on
the upper and lower limb of the first gill arch,
lateral line pores, and diagonal scale rows below
the lateral line. In some cases Inda ink was applied
to the right side of a fish to increase visibility of the
latter two features.

^The term "meristic" is used here to refer to all countable
characters.

Morphometries

Measurements of various body parts of selected
specimens were made to the nearest 10th or 100th
of a millimeter using an ocular micrometer in a
stereomicroscope as follows:

Standard length (SL) = snout tip to notochord
tip preceding development of caudal fin, then to
posterior margin of hypural plate.

Snout to anus length = distance along body mid-
line from snout tip to vertical through posterior
margin of hindgut at anus.

Head length (HL) = snout tip to cleithrum until
no longer visible, then to posteriormost margin of
opercle (SL of 30.3 mm on S. crameri, 16.8 mm on
S. pinniger, 41.6 mm on S. helvomaculatus).

Snout length = snout tip to anterior margin of
orbit of left eye.

Upper jaw length = snout tip to posterior mar-
gin of maxillary.

Eye diameter = greatest diameter of left orbit.

Interorbital distance = distance between dorsal
margins of orbits.

Body depth at pectoral fin base = vertical dis-
tance from dorsal to ventral body margin at base of
pectoral fin.

Body depth at anus = vertical distance from
dorsal to ventral body margin immediately poste-
rior to anus.

Pectoral fin length = distance from base to tip of
longest ray.

Pectoral fin base depth = width of base of pec-
toral fin.

Pelvic spine length = distance from base to tip of
pelvic spine.

Pelvic fin length = distance from base to tip of
longest ray.

Snout to origin of pelvic fin = distance along
body midlme to vertical through insertion of pel-
vic fin.

Parietal spine length = distance along posterior
margin of parietal spine from insertion to tip.

Nuchal spine length = distance along posterior
margin of nuchal spine from insertion to tip.

Preopercular spine length (third spine, posteri-
or series) = distance from tip to basal insertion if
visible, or to a line connecting the points of deepest
indentation between preopercular spines 2 and 3
and spines 3 and 4 (posterior series).

Length of angle gill raker = distance from tip
of gill raker to point of articulation with gill
arch.

FISHERY BULLETIN: VOL. 77. NO. 1

Table l .—Summary of data on preextrusion larvae (P) or newborn, reared larvae (L) of northeast Pacific speciesof Se6astes. Asterisk

indicates figure is included.

Source

Species

C 00

a> (O

>.2

F . n

O CD

S "^

O (o
■Q CD

E -5 £ E -

___ c
at ">

^ o
"> ™ o

Q) CD i:

-ill

C 0) ?r

*= O E w CD

0) X -;

2

S aleulianus
S alutus
S atrovirens
S aunculatus
S aurora
S babcocki
S borealis
S brevispinis
S carnatus
S caunnus
S chlorostictus
S chrysomelas
S ciliatus
S constellatus
S cortezi
S cramen
S dalli
S diploproa
S elongatus
S emphaeus
S ensfter
S entomelas
S eos
S exsul
S flavidus
S gilli
S goodei
S helvomacuiatus
S hopktnsi
S lord am
S lentiginosus
S levis

S macdonaldi
S maliger
S melanops
S melanostomu .
S miniatus
S. mystinus
S nebulosus
S nigrocmctus
S notius
S ovalis
S paucispinis
S peduncularis
S philtipsi
S pinniger
S polyspinis
S pronger
S rasfrelliger
S reedi
S rosaceus
S rosenblatti
S rubernmus
S rubnvinctus
S rufi nanus
S rufus
S saxicola
S semicinctus
S serranoides
S sernceps
S simulator
S sinensis
S spinorbis
S umbrosus
S variegatus
S. vanspinis
S wilsoni
S zacentrus
S new sp (Lea
and Fitch)

(P-1

L-
L'

L-

P-

P*

'Described as S rubnvinctus. but northern occurrence indicates it must be S babcocki

^Described as S rhodochloris

^These descriptions ot S rubnvinctus must be S babcocki due to the northern occurrence of specimens.

RICHARDSON and LAROCHE DEVELOPMENT AND OCCURRENCE OF ROCKFISHES

Longest dorsal fin spine = distance from base to
= distance from base to
= distance from base to

tip

Longest dorsal fin ray =
tip.

Longest anal fin spine
tip.

All body lengths given refer to standard length
unless noted otherwise.

Developmental Terminology

Terminology for development of Sebastes spp.
used in this paper is as follows:

Preflexion larva = prior to notochord flexion.

Flexion larva = undergoing notochord flexion
from time urostyle begins to slant upward until
urostyle is in final upturned position and caudal
fin is formed.

Postflexion larva = from completion of noto-
chord flexion (urostyle may still extend beyond the
base of the caudal fin) to onset of transformation of
13th dorsal spine and 3d anal spine from soft ray to
spine, and to the associated onset of development
of juvenile pigment pattern (usually addition of
pigment to the dorsum).

Transforming larva = from onset to completion
of transformation of 13th dorsal spine and 3d anal
spine from soft ray to fully developed spine. Also
from the onset of development of juvenile pigment
pattern to development of distinctive juvenile
pigmentation, often in the form of melanistic sad-
dles over the dorsum.

Pelagic juvenile = from completion of formation
of 13th dorsal and 3d anal spine (and thus attain-

ment of adult complement of actual fin spines and
rays) and development of juvenile pigmentation
until no longer captured pelagically.

Benthic juvenile = from time of first capture on
bottom and usual associated decrease in intensity
of melanistic pigmentation to attainment of sex-
ual maturitv.

Spination (Figure 1, Table 2)

Difficulties arise in naming all the spines found
in the head region of larvae and juveniles of
Sebastes because not all are found in adults.
Further complications arise because the names
traditionally used for a number of the head spines
do not reflect the bone from which the spine origi-
nates. For these reasons we include a composite
diagram of spines which may occur during the
larval and juvenile periods. The terminology is a
combination and modification of that used by Phil-
lips (1957), Chen ( 1971), Moser (1972), and Moser
and Ahlstrom (1978). Most names used in this
paper are the same as those used for adult
rockfishes to avoid confusion, even though the
bones from which the spines originate are not in-
dicated by the name. Exceptions are as follows.
The two spines found on the opercular margin are
here called the subopercular and the interopercu-
lar according to the bones from which they origi-
nate. The superior posttemporal (supracleithral of
adults), inferior posttemporal (not found in
adults), and supracleithral (cleithral of adults) are
so-called because of their origin. This is done to
avoid confusion with a spine present on the poste-
rior margin of the cleithrum, which is here called
the cleithral spine. Use of the term infraorbital

INFERIOR INFRAORBITAL SERIES. 1ST
SUPERIOR INFRAORBITAL SERIES, 1ST

SUPERIOR INFRAORBITAL SERIES, 2ND

INFERIOR INFRAORBITAL SERIES. 2ND --'
INFERIOR INFRAORBITAL SERIES, 3RD -'"
SUPERIOR INFRAORBITAL SERIES, 3RD
SUPERIOR INFRAORBITAL SERIES, 4 TH

ANTERIOR PREOPERCULAR SERIES, I ST- 3RD

POSTERIOR PREOPERCULAR SERIES, IST-5TH

INTEROPERCULAR
SUBOPERCULAR

INFERIOR OPERCULAR
SUPERIOR OPERCULAR

NASAL

PREOCULAR

SUPRAOCULAR

F'jST'XULAR

Ip'

TrMPANIC

PTEROTIC

PARIETAL
NUCHAL

r.FERIOR POSTTEMPORAL
-yjPERIOR POSTTEMPORAL
SUPRACLEITHRAL

Figure l . — Composite diagram of spines present in the head region of larval and juvenile Sebastes species
including names used in this paper. Refer to Table 2 for correspondmg names used for adults and bones
from which spines originate.

FISHERY BULLETIN VOL

.NO 1

Table 2. — Names of head region spines of larval and juvenile Sebastes spp. used in this paper with
corresponding names used for adults and bones from which the spines originate. Spines listed in the
first column are shown in Figure 1 clockwise beginning with the nasal.

Bone from which

Name used in this paper

Name used in adults^

spine(s) originates^

Nasal

Nasal

Nasal

Preocular

Preocular

Prefrontal

Supraocular

Supraocular

Frontal

Postocular

Postocular

Frontal

Coronal

Coronal

Frontal

Tympanic

Tympanic

Frontal

Rerotic

Pterotic

Pterotic

Panetal

Panetal

Parietal

Nuchal

Nuchal

Parietal

Interior postlemporal

—

Postlemporal

Superior postlemporal

Supracleithral

Postlemporal

Supracleithral

Cleithral

Supracleithrum

Cleithral

—

Cleithnjm

Superior opercular

Opercular

Opercle

Inferior opercular

Opercular

Opercle

Subopercuiar

Gill cover spine

Subopercle

Interopercuiar

Gill cover spine

Interopercle

Posterior preopercular senes. lst-5th

Preopercular

Preopercle

Antenor preopercular series. 1sl-3d

—

Preopercle

Superior infraorbital senes, 4th

—

Infraorbilal 3 (2d suborbital)

Superior infraorbital senes

—

Infraorbital 2 fist suborbital)

Inferior infraorbital series, 3d

—

Infraorbital l (preorbital)

Inferior infraorbital series, 2d

Lachrymal projection (suborbital spine)

Infraorbital 1 (preorbital)

Superior infraorbital series, 2d

—

Infraorbital 1 (preorbital)

Superior infraorbital series. 1st

—

Infraorbital 1 (preorbital)

Inferior infraorbital series, isl

Lachrymal projection (suborbial spine)

Infraorbital 1 (preorbital)

'After Phillips (1957) and Chen (1971)
■'Afler Malsubara (1943) and Weitzman (1962)

follows Weitzman (1962
Poss.*

as recommendeii by

SEBASTES CRAMERl (JORDAN)

(Figures 2, 3, 4)

Literature. — Pigment patterns of preextrusion
larvae of S. crameri were described by Westrheim
et al.," including one figure, and Westrheim
(19751. Preextrusion larvae (mean total length =
5.7 mm) have a rowof 10 to 23 melanophores(45'7f
of 60 larvae had <16 melanophores) along the
ventral body midline which stops short of the anus
by four myomeres. Melanophore(s) are also usu-
ally present on the ventral finfold in the hypural
region. The gut is pigmented. No pigment occurs
on the head, nape, or dorsal body midline, how-
ever. Westrheim ( 1975) reported that S. crameri
larvae, along with several other species, reared for
several days develop pigment spots on the head,
nape, and or lower jaw.

*S. G. Poss, Ph.D. Candidate, Department of Zoolog>', Univer-
sity of Michigan, Ann Arbor, Ml 48109. pers. commun. .Julv
1977.

'Westrheim, S. J., W. R. Harling, and D. Davenport.
1968, Preliminary report on the maturity, spawning season
and larval identification of rockfishes i.Sebastotles ) collected off
British Columbia in 1967. Fish. Res. Board Can., Manuscr
Rep. 9.51.23 p.

Identification (Table 3, Appendix Tables 2-6l. —
Eighty-one specimens of S. crameri, ranging from
8.0 to 130.5 mm, were identified. Juveniles were
identified using the following combination of
characters recorded from specimens in our collec-
tions:

Gill rakers = 30-34

Lateral line pores = 43-50

Pectoral fin rays = 18-20, usually 19

Anal fin soft rays = 7

Dorsal fin soft rays = 13-15

Supraocular spine = present

Interorbital space = flat to convex.

No other species on our list of potential species
agrees with all these characters. In addition, the
characteristic pigment banding of adults was ob-
vious on larger juveniles. Larvae and juveniles
were relatively abundant in our collections and
adults are known to be abundant in terms of
biomass in trawl catches off the Oregon coast
(Demory et al. 1976; Niska 1976). The develop-
mental series was linked together primarily on
the basis of pigmentation and also body shape and
time of occurrence. Identification of most of the
smaller specimens was further substantiated by
meristics, particularly the constancy in nurn lor of
anal and pectoral fin rays (Table 3).

RICHARDSON and LAROCHE DEVELOPMENT AND OCCURRENCE OF ROCKFISHES

9.0 mm

12.6 mm

14.7 mm

FICI RE 2.— Planktonic larvae (9.0, 12.6, 14.7 mml of Si>6as/(?,s crameri.

FISHERY Bl'LLETIN VOL 77. NO

'). •''

19.0 mm

3.<^

, ^'¥i^>:J^. '^-/

r %-':^«^<

5c^-

t-'

^^-"f^

;i^('

22.7 mm

31.8 mm

FICL'RK 3.— Transforming specimen 1 19.0 mmi and pelagic juveniles (22.7, 31.8 mmi t,{ Sebastes cr,

RICHARDSON and LAROCHE DEVELOPMENT AND OCCURRENCE OF ROCKFISHES

V> 'X>\

56.9 mm

..r^'^^^s^^s^s

78.8 mm

Figure 4. — Pelagic juvenile (56.9 mm) and benthic juvenile (78.8 mm) oC Sebastes crameri.

Distinguishing Features. — Characters useful to
distinguish the smallest i(ientified larvae (8.0
mm) are the heavily pigmented pectoral and pel-
vic fins, the presence of a heavy nape pigment
patch from which some melanophores extend
down and over the gut externally on the body wall,
the absence of dorsal midline pigment other than
at the nape, the presence of ventral midline pig-

ment as =11 distinct melanophores of which the
anterior ones are embedded and only the posteri-
ormost ones remain on the ventral body surface,
and pigment at the tip of the lower jaw. The pres-
ence of pigment on the first dorsal fin in larvae as
small as 11 mm is also a useful character. Meris-
tics, presence of a supraocular spine, flat to convex
shape of the interorbital space, heavily pigmented

FISHERY BULLETIN: VOL. 77. NO. 1

Table 3. — Meristics from larvae and juveniles ofSebastes crameri off Oregon, based on unstained specimens. Specimens above dashed
line are undergoing notochord flexion. All specimens had 8 superior and 7 inferior principal caudal fin rays and 7 branchiostcgal rays on
each side.

Standard
length
(mm)

Dorsal
fin spines
and rays

Anal
fin spines
and rays

Pectoral
fin rays

Pelvic f
spines and

Left

n
rays

Right

3111 rakers
first arch)

Lateral
line pores

Diagonal
scale

Left

Right

Left

Right

Lett

Right

rows

B.O

(')

(')

—

19

(')

(')

_

8.0

(')

(')

19

19

i')

P)

—

—

—

—

—

9.0

III + IM3-14

P.7

19

19

M')

l.C)

_

9.0

P. 14

P.7

19

19

I.C)

1,0

_

—

—

—

9.3

P. 14

P.7

19

19

l.C)

1,0

-

—

—

—

—

10,6

VI + IM3

P,7

19

19

1.5

1,5

S

10.6

VlllfP.14

ll',7

19

19

1,5

1.5

_

_

_

—

—

10.7

IX + I'.13

IP, 7

—

19

1,5

1.5

—

12.2

X + 11.14

IIP,7

19

19

1,5

1.5

_

19+ 8=27

_

—

_

12.6

XUIM3

IIP.7

19

19

1,5

1.5

—

= 19+ 8=27

_

_

_

12.8

Xl»|i.l4

IIP.7

19

19

1,5

1.5

—

—

—

_

13.6

XIIIM3

IIP.7

19

19

1,5

1.5

_

-18+ 8=26

—

—

_

13.8

XIIIM4

IIP,7

19

20

1.5

1.5

_

-20+ 8=28

—

_

_

14.4

XIIP.14

IIP,7

19

19

1,5

1.5

—

-20+ 8=28

_

—

_

14.7

XIIP.14

IIP.7

20

19

1,5

1.5

_

21+ 9 = 30

_

_

_

15.4

XIIP.14

IIP.7

18

18

1,5

1.5

—

—

_

_

_

'16.0

XIIP.14

IIP.7

19

19

1,5

1.5

—

21+ 8=29

_

_

_

'16.3

XIIP,14

IIP.7

19

19

1,5

1.5

—

22+ 8=30

—

_

_

'17.3

XIIIM3

IIP.7

19

19

1.5

1.5

—

21+ 9=30

_

_

_

'17.4

XIIIJ.13

IIP.7

19

19

1,5

1.5

_

22+ 9=31

_

—

—

'18.2

Xlll^,14

IIP.7

19

19

1.5

1.5

_

20+ 9=29

_

_

_

'18.4

XIIP,13

IIP,7

20

19

1,5

1,5

—

22+ 9=31

—

—

—

'18.6

XIIIM4

IIP.7

20

20

1,5

1.5

_

22+ 8=30

_

_

_

'19.0

XIII-M4

IIP.7

19

20

1,5

1.5

_

22+10 = 32

_

—

—

'20.0

XIIP.14

IIP,7

19

19

1.5

1,5

21^

9-

= 30

22+ 9=31

_

_

_

'20.3

XIIIJ.14

IIP.7

19

19

1,5

1,5

22 +

9 =

=31

22+ 9 = 31

—

—

—

*21.0

XIIP.14

IIP,7

19

19

1.5

1.5

22 +

9-

=31

21+ 9=30

_

_

_

522.7

XIII.13

III.7

20

20

1.5

1.5

22 +

9

=31

22+ 9 = 31

_

523.5

XIII. 13

111,7

19

19

1.5

1.5

23 +

9

=32

22+10=32

_

=24.2

XIII.14

111,7

19

19

1.5

1.5

23 +

9

= 32

22+ 9=31

_

—

—

525.6

XIII.15

III.7

19

20

1.5

1.5

22 +

9

= 31

23+ 9=32

_

_

_

528.6

XIII.14

111,7

19

19

1.5

1.5

22 +

9

=31

23 + 10 = 33

—

=30.0

XIII.13

III.7

19

19

1.5

1.5

22 +

9

=31

23+ 9=32

•48

-47

_

531.8

Xlil.l3

111,7

19

19

1.5

1.5

23 +

10 =

=33

22+10=32

46

_

_

535.7

XIII.14

III.7

19

19

1.5

1.5

23-

9

= 32

23+ 9 = 32

45

-43

—

538.2

XIII.14

111,7

19

19

1.5

1.5

23 +

10

=33

23+ 9=32

—

—

_

556.9

XIII.14

III.7

19

19

1,5

1.5

22 +

9

=31

22+ 9 = 31

45

46

_

546.8

XIII.13

III.7

19

19

1,5

1.5

24 +

9

=33

23+ 9=32

-48

—

—

549.2

XIII.14

111,7

19

19

1.5

1.5

23 +

10

=33

24 + 10=34

^43

=46

_

558.9

XIII.14

III.7

19

19

1.5

1.5

22+

9

=31

22+ 9=31

45

45

—

563.0

XIII.14

III.7

19

19

1.5

1.5

23 +

9

=32

23+ 9=32

45

46

_

563.2

XIII.13

III.7

19

19

1.5

1.5

22 +

9 =

=31

23+ 9=32

JO

46

_

565.0

XIII.14

111.7

19

20

1.5

1.5

24 +

9

= 33

24+ 9=33

49

50

_

567.6

XIII.14

111,7

19

19

1.5

1.5

22 +

10

= 32

23 + 10=33

47

48

—

578.8

XIII, 14

III.7

19

19

1,5

1,5

22-

9-

-31

22- 9-31

48

44

_

'86.1

XIII.13

111,7

19

18

1.5

1,5

23 +

9

=32

23+ 9=32

46

46

_

591.8

Xlll,14

III.7

19

19

1.5

1,5

22 +

10

= 32

23-10=33

47

49

-53

594.4

XIII.14

III.7

19

19

1.5

1,5

22 +

8

=30

22- 9=31

49

47

-59

594.7

XIII.14

111,7

19

20

15

1,5

23 +

10

=33

23- 9=32

45

45

—

596.2

XIII.13

III.7

19

18

1.5

1,5

22 +

9

=31

22+ 9=31

47

45

•55

5105 6

XIII.13

111,7

19

19

1.5

1.5

22 +

9 =

-31

22+ 9 31

47

47

-51

5125.7

XIII.14

111,7

19

19

1.5

1.5

23-

9 =

-32

23+10-33

45

44

-59

5130.5

XIII.13

111,7

20

2"

1.5

l.."^

23 +

10 =

=33

23+ 9=32

46

47

-60

forming

^Nol formed

^Posteriormost dorsal or anal spine appears as a soft ray

^Transforming.

^Pelagic juvenile

5Ben1nic juvenile

pectoral and pelvic fins, and pigment banding pat-
tern on the body serve to distinguish juveniles.

General Development. — The smallest specimens
(8.0-9.0 mm) of S. craryieri in the series are under-
fi^o'.ig the final stages of notochord flexion, which i.'^
completed by the time larvae are 10 mm. Trans-
formation from postflexion larvae to pelagic
juveniles is rather gradual beginning when larvae

are about 16 mm. It is charactorized by addition ot
pigment beneath the second d^rs.'l fin along witli
initiation of structural change of ihe "prespines"
in the dorsal and anal fins. Tr.msformation is
complete in 22 mm specimens and the juvenile
pigment pattern is obvious. Transition from
pelagic to bentbic habitat probably occurs when
fish are 40 to 60 riim. The largest 1 elagif uvenile.
captured in a neuston net. was 56.9 mm and the

1'

RICHARDSON and LAROCHE DEVELOPMENT AND OCCURRENCE OF ROCKFISHES

smallest juvenile taken in a bottom trawl was 46.8
mm.

Morphology (Tables 4, 5). — Measurements of var-
ious body parts were made on 53 selected speci-
mens of S. crameri, ranging from 8.0 to 130.5 mm
long, to examine developmental morphology. Rel-
ative body depth at the pectoral fin base and at the
anus increases somewhat, 32 to 34% SL and 24 to
28'7f SL, respectively, during development from
flexion larvae to benthic juveniles. A more marked
change occurs in snout to anus distance which
increases from 54 to 65'7f SL. The distance from the
snout to the pelvic fin base increases slightly.

Head length decreases somewhat during de-
velopment from 39 to 369c SL, while major de-
creases occur in eye diameter (40-33% HL), upper
jaw length (56-41% HL), and interorbital distance
(36-23% HL). Snout length first increases slightly
and then decreases with respect to head length.
The length of the angle gill raker increases from 9
to 16% HL.

Fin Development (Tables 3, 4, 5). — Pectoral fins
are formed in 8 mm larvae of S. crameri and the
adult complement of 18 to 20 (usually 19) fin rays
(or ray elements) are countable in 9 mm speci-
mens. The fins become more elongate with de-
velopment, increasing from 17% SL in flexion lar-
vae to a maximum of 32% SL in pelagic juveniles.
Depth of the pectoral fin base decreases from 13 to
10% SL.

Pelvic fin buds are present on 8 mm lai'vae and
the forming spines and rays (1,5) can be counted in
9 mm larvae although they are not fully developed
until the larvae reach about 10 mm. Length of the
pelvic fins increased from 7 to 21% SL during the
larval and juvenile periods. Length of the pelvic
spine, which is less than the longest ray, increases
from 5%' SL in flexion larvae to 19% during trans-
formation, and then decreases to an average of
13% in benthic juveniles.

In 8.0 mm larvae the adult complement of 8 -i- 7
principal caudal rays can be counted although
notochord flexion does not appear to be complete
until larvae are >9.3 mm. Counts of superior and
inferior secondary caudal rays made on one
stained juvenile, 38.2 mm, were 12 and 13, respec-
tively.

Bases of some dorsal and anal fin rays and
spines are visible on 8 mm larvae. Development of
the second dorsal and anal soft rays occurs simul-
taneously with the central rays forming first and

the posteriormost rays last. Developing soft ray
elements are visible and adult complements can
be counted on 9 mm larvae although rays do not
appear fully formed until larvae are >10 mm.
Dorsal spines begin to form slightly after initia-
tion of soft ray formation at =9 mm. The third,
fourth, and fifth dorsal spines develop first. The
12th spine is not formed until larvae are >13 mm
long. The second anal spine is formed at 10.6 mm
and the first is formed by 12 mm. The transition of
dorsal and anal fin "prespines" to spines is com-
plete at around 22 mm. The longest dorsal spine
increases from 22 to 45% HL during the pelvic
phase, and decreases to 37% in benthic juveniles.
The longestdorsal ray increases from 26 to 41-43%
HL during development. The longest anal spine
increases from 16 to 37 or 38% HL.

Spination (Tables 4, 6). — Spines visible on the left
side of the head of an 8.0 mm larva of S. crameri
consist of the parietal; the second, third, and
fourth preopercular spines of the posterior series;
the first, second, and third preopercular spines of
the anterior series; the postocular; and the pterot-
ic. Another more developed 8.0 mm specimen has a
developing nuchal spine bump; the inferior post-
temporal; the first spine of the inferior infraorbital
series, and the first spine on the superior infraor-
bital series.

The parietal spine is relatively short, averaging
6.5 to 6.6% HL in larvae and decreasing to 3.0%
HL in pelagic juveniles. The nuchal spine in-
creases in length from 1% HL in flexion larvae to
4% in postflexion and transforming specimens
then decreases to 3% in pelagic juveniles. Parietal
and nuchal spines begin to fuse near their bases at
10.7 mm, gradually fusing towards the tips until
in specimens >38 mm the parietal tip is no longer
visible. In benthic juveniles the nuchal and
parietal spines are fused and their relative lengths
are =2% HL; however, increased pigment and
musculature allowed measurement only from tip
to body junction. The parietal spine and ridge are
not serrated in larvae <9 mm. Serrations first
appear at the center of the parietal ridge at 9 mm
and persist until =39 mm.

The posterior series of preopercular spines are
among the most prominent in the larvae. The first
through fifth spines of the series are present in
larvae >10 mm. The third spine of the series is the
largest, averaging 17 or 18% HL in larvae and
then decreasing to 7% HL in benthic juveniles.
Spines in the posterior preopercular series never

11

FISHERY BULLETIN: VOL. 77. NO. 1

Table 4.— Body proportions of larvae and juventies of Sebastes cramen.S. pinniger. andS. helvomaculatus .
Values given are percent standard length iSL) or head length (HLl including mean, standard deviation, and
range in parentheses. (Number of specimens measured may be derived from Tables 5, 8. and 11.)

Item

Sebastes
cramerl

Sebastes
pinniger

Sebastes
helvomaculatus

Body depth at pectoral tin baseiSL:
Flexion
Postflexion
Transforming
Pelagic Juvenile
Benthic Juvenile
Body depth at anusiSL:
Flexion
Postflexion
Transforming
Pelagic Juvenile
Benlhic Juvenile
Snouf fo anus length SL:
Flexion
Postflexion
Transforming
Pelagic Juvenile
Bentfiic Juvenile
Snout to pelvic fin ongin:SL
Flexion
Postflexion
Transforming
Pelagic Juvenile
Benthic Juvenile
Head lenglh'SL
Flexion
Postflexion
Transforming
Pelagic Juvenile
Benthic Juvenile
Eye diameterlHL:
Flexion
Postflexion
Transforming
Pelagic Juvenile

Benthic Juvenile
Upper law length HL
Flexion
Postflexion
Transforming
Pelagic Juvenile

Benthic Juvenile
Snout lengthHL
Flexion

Postflexion

Transforming

Pelagic Juvenile

Benthic Juvenile
Interorbital distance HL-

Flexion

Postflexion

Transforming

Pelagic Juvenile

Benthic Juvenile
4r7g/e gill raker length HL

Flexion

Postflexion

Transforming

Pelagic Juvenile

Benthic Juvenile
Longest dorsal spine length^ HL

Flexion

Postflexion

Transforming

Pelagic Juvenile

Benthic Juvenile
Longest dorsal ray length^ HL.

Flexion

Postflexion

Transforming

Pelagic Juvenile

Benthic Juvenile
Longest anal spine length^ HL:

Flexion

Postflexion

Transforming

31.8±2.05(29.0-33.8)

31. 7 ±1,26(30 3- 34 9)
32.4±1 74(29 5-35 6)
32.7±1 89(30,3-37.4)
34.4±1,96( 30.1-36.5)

23.6^0 67(22 6-24 4)
24 9±1 19(22 6-26 5)
26.7±1 34(24 7-29 4)

26.8 ±1 15(26 2-29.2)
27.7±1 56(25 1-30 7)

54.0±1 28(52 5-559)
60.5±325(55 1-65 1)
61 .a±3 26(54 3-65 0)
61 .6 ±2 63(57 9-64 3)
65.0:!: 1.81(61. 5- 68 7)

37.6±1 56(35.0-38.9)

40 8±2 02(38 1-44 3)
39 8±3 49(34 1-46.5)
38.9±3 23(34.0-44 5)
40.5 ±1.86(37.3-43.1)

39.0±1 55(37 5-41 1)

38.9 ±1 90(36 8-43 4)
36 6 ±2 43(32 8-38 7)
35.8±1 82(32 3-38 3)
36.4 ±2 75(31 8-39 9)

40.2±1 82(37 8-42 9)
38.2± 1.87(33 9-40 0)
36 9±2 47(33 3-42 1)
30 4 ±2 60(26 6-35 0)
31 .6±2 05(28 9-35 6)

46.5±4.35(40.5-50.0)
43 6±2 45(40 0-46 3)
438±5 55(34 2-50 9)

41 3±4 06(33 9-47 5)
41 2±2 44(37 8-45 6)

29.1 ±1 38(27 0-30 7)

30 0±1 65(26 1-31 7)

31 2±2 69(27 0-35 6)
28 2±2 97(24 6-32 1)
26.3±2.43(22 4-31 2)

35.6 ±1.95(32 4-37 1)
33.0±1 94(29 3-36 0)
31 2±339(259-368)
25 9±2 48(23 0-30 0)
21.6±2 18(18 0-26.8)

8.6±0.00(8.6)
11 4±1 77(8 6-14 4)
13 1 ±1 13(11 1-15 1)
139±082(13 3-15 1)
158tl 06(13 7-174)

21 6±2. 26(19 4-24 1)
34.3±7 13(26 2-45 1)
44 7± 1.55(42 0-46 2)
36.9 ±4 32(31 7-44 3)

26.2±6.96(14 6-33 3)
41.4±232(39 3-43 9)
42.0±2 97(38 1-46 7)
43 1*4 74(37 6-48.1)

15 6±3.16(9 6-18.5)
28.1 ±3 46(23.0-32 0)

40.3±0.92(39.7-41 0)

38 1 ±2 51(33 7-42 0)
35 9±1 36(33 3-38 3)
33.0 ±1.88(29.8-37 0)
34.9±2 15(32 7-37.0)

27 6 ±0 92(26 9-28 2)
285-1 92(24 7-30 6)
27 6»1 63(24 8-30 9)
26.0±1. 11(239-28.0)
29 8±3 68(27 3-34 0)

58 8±1 63(57 7-60 0)

59 6 ±3 42(51 7-62 6)
606 • 1 84(58 1-63 1)
61 4. '3 50(56 0-67 4)
64 2±3 27(60.6-67 0)

41 1 ±3 61(38 5-43 6)

40 7±3 03(34 7-44 9)

41 9*2 74(38 7-46 2)

39 9±3 83(32 9-45-5)
42.7±2.86(41.0-460)

43 ±0.92(42.3-43 6)

42 4 • 2 58(38 2-47 7)

40 5±1 39(38 0-42 6)
37 5±2 52(33.3-42 1)
366±0 51(360-37 0)

37 3

1 27(36.4-38 2)

39 3

1 89(37 5-41 3)

37 5

1 35(34 2-38 7)

34 2

2 77(30 8-42 3)

26 8

-3 22(24 0-30 3)

47 8

-0 99(47 1-46 5)

46 1

3 73(41 2-524)

42 1

►3.64(35.6-47.0)

41 3-

3 14(34.6-47 4)

44 9

±2 15(42 7-47 0)

26 9

►0 28(26 7-27 1)

28 7

-3 45(23.8-34 8)

30 2

±3 31(25 8-36 5)

27 3

*3 68(21 7-32 5)

28 8

±0 72(28 0-29 4)

37 3

•127(36 4-38 2)

342

±2 26(30 4-38 2)

30

± 1 82(26 3-32 3)

24 4

•3 31(19 5-30 8)

198

•137(183-210)

106

±1 42(8.3-123)

130

•0 72(11 5-14 5)

14 1

±1 21(11 7-16 5)

149

±1 10(138-160)

20 1 ±6 05(13 0-28 6)
32 4 •5 49(23 6-40 6)
38 0±3 79(33.1-46 2)
35 6±4 74(32 0-41 0)

31 5 ±4 26(23.8-38 0)
38 5± 3 60(30 8-42 9)

41 6 ±3 46(35 4-48 7)

42 6±3 83(40 0-47 0)

18 7 ±2 52(14 6-21 3)
28 5 ±5.65(20.0-38 6)

33 3 ±1.44(32.5-35.0)
33 4 ±0 46(33 0-33 9)

32 6±1 79(30 6-35 8)
31 2 ±1.58(28 4-32 9)

33 4 ±1.63(32-3-34.6)

20 7±0.61(20.0-21 2)
24 5 ±2.56(21 6-26 3)

24 7±1 22(23.1-26.9)
23 2±1 24(21 2-25.0)

25 4 ±2 33(23 7-27 0)

56 1 ±1.28(55 0-57 5)
59 1 ±0 50(58 6-59 6)

61 7±1 86(59 2-64 5)

62 8 ±2 46(59 8-66 0)
638*1 06(630-645)

40 5±1 27(39 0-41 2)
40 9±0 45(40 4-41 3)
42 8=3 13(38 0-47 3)
42 8±3 16(39 3-48 2)
40 ±0 92(39.4-40.7)

41.4±1.27(40 0-42.5)
42.0±2 03(40 4-44.3)
40 8±1 92(36 4-43 0)
40 1±1 48(37 5-41 9)

37 6 ±0 57(37 2-38 0)

38 8±1 63(29 4-31 2)
36 3±0.36(35 9-36 6)
35 5 ±2 38(32 0-38 8)
33 6 : 1 76(30 8-36 9)

31 6±5 30(27 8-35 3)

45 ±3.29(4 1.2-46.9)

44 0±3 00(41 0-47 0)

45 7 ±4 23(39 7-53 1)
45 1 ±2 63(40 2-47 6)
52 1 ±0 78(51 5-52.6)

32 3±2 20(30 0-34 4)
330±1 18(31 7-34 1)
32 4±3 72(25 0-37 9)
31 7 ±2.49(26 7-34 1)

26 7±0.42(26.4-27 0)

30 6±1 04(29 4-31 2)

31 4 ±0 55(30 8-31 8)

27 0±2 89(23 3-30 6)
21 5±3 83(13 3-25 6)
146±247(129-164)

134±095(12.3-14 1)
15 1±1 46(12 9-180)
14 2±1 90(12 7-15 7)
10 6±0 50(10 3-1 10)

19 0±0 64(18 6-19 5)

29 2±6 08(22 4-37 5)

30 9±2 93(28 0-35 7)
37 ±4.88(33 6-40 5)

22 8±7 39(1 5 9-30 6)
26 4 ±5 14(20 5-29 5)
36 1 ±3 08(32 5-41 7)
35 1 ±2 53(32 0-38 1)
42 8 ±3 89(40 0-45 5)

160±1 91(146-173)
27 3 ±4 46(22.4-36 1)

12

RICHARDSON and LAROCHE, DEVELOPMENT AND OCCURRENCE OF ROCKHSHES

Table 4.— Continued.

Item

Sebastes
cramen

Sebastes
pinniger

Sebastes
helvomaculatus

Pelagic Juvenile

Benthic Juvenile
Pectoral fin length SL

Flexion

Postflexion

Transforming

Pelagic Juvenile

Benthic Juvenile
Pectoral tin base depth SL

Flexion

Postflexion

Transforming

Pelagic Juvenile

Benthic Juvenile
Pelvic fin length 'SL:

Flexion

Postflexion

Transforming

Pelagic Juvenile

Benthic Juvenile
Pelvic spine length SL

Flexion

Postflexion

Transforming

Pelagic Juvenile

Benthic Juvenile
Parietal spine lengthHL

Flexion

Postflexion

Transforming

Pelagic Juvenile

Benthic Juvenile
Nuchal spine length HL

Flexion

Postflexion

Transforming

Pelagic Juvenile

Benlhic Juvenile
Preopercular spine lengthiHL

Flexion

Postflexion

Transforming

Pelagic Juvenile

Benthic Juvenile

37 8-4 36(31,2-43 5)
36 5*4 34(30 6-44 31

17 1 ±1 52(150-189)
21 1 12 26(17 0-23 5)
27 1^1,54(24 7-29 5)
32 1-1 73(30 2-35 3)
29 5±3 61(25 0-38 9)

126-1 27(108-138)
11 IrO 39(10 4-11 8)
104±061(95-11 7)
96i051(85-102)
10,2:0 53(8 8-10 9)

7,3:1 81(52-98)
15,3:1 46(12,3-16,9)
20 6:1 01(18.3-22 1)
20 9:0 60(20 1-21 9)
20 7 '0 97(18 5-22 2)

4 7:1 42(3 4-6 2)
11 4:2 20(6 8-14 6)

18 8:1,65(14,5-20 1)

19 0:1 35(16.2-20,7)
13 9:1 34(12,3-17 1)

65:1 01(54-7 4)
6 6:1 06(5 2-8 5)
6 0:1 24(3 7-7 4)
2 9:0 98(1 8-4 2)

1 1 :0 00(1 1)
4 1 :0 73(3 4-5 8)
44:088(3 1-6 0)
3 2:1 03(2 0-5 0)
1 7:0 64(0 7-2 8)

176 13 84(120-205)
170:1 09(15 5-185)
183:1 53(160-19,7)
12 0:2 85(8 6-16 2)
72:2 72(3 Ml 4)

37 4:4 07(30 8-44 0)
34 5:2 50(32 0-37 0)

25 0:2 69(23 1-26 9)
24 7:2 64(20 2-28 5)
27 0:2 42(22 7-31 5)

26 2:1 36(24 0-28 5)
243:1 21(22 9-25 0)

148:092(14 1-154)

12 6:083(11 4-13 6)
107:0 69(9 7-11 5)

9 1:0 64(8 2-10 1)
8 9:0.23(8 6-9 0)

13 8:2 19(12 3-15 4)
172:4 12(10 0-22 8)
22 7:1 59(20,8-25 3)
21 7:1,29(19,4-23 7)
21 3:2,08(19.0-23 0)

5 1:0 00(5 1)
12 1:299(82-150)
19.5:1 38(17 6-21 7)
17 9:2 10(14 5-22 1)
125:0 50(120-130)

24 4:0 35(24,2-24 4)
19 5:7 17(8 8-23 5)
10 2:3 07(3 9-12 9)
7 1:2.66(5.4-10 2)

4 4:1 63(2 5-6 9)
4 8:1 57(2 3-7 2)

3 1:0 96(1 9-5 4)
1 4:0 64(1 0-2 1)

34 4:2 83(32 4-36 4)
31 8:4 86(25 0-39 0)
23 6:2 09(21 2-29 1)
12 8:3 96(9 1-22 2)

4 8:1 39(4 0-6 4)

32 4:5 70(26 8-38 1)
48 8:4 67(45 5-52 1)

23 6:2 11(21 2-25 0)

24 4-0 57(23 9-25 0)
26 : 1 45(24 3-28 3)

26 6:0 28(26 1-26 9)

27 0:0 85(26 4-27 6)

12 5:0 00(12 5)

11 5:084(11 0-125)
9 9:0 64(9 0-10 8)
90:033(82-9 1)

9 3:0 71(8 8-9 8)

135:1 32(125-150)
155:070(148-162)
193*1 62(167-21 6)
192- 1 36(173-21 4)
22 7 1 99(22 0-23 4)

8 3:0 15(8 2-8.5)

12 3:2 26(10 2-14 7)
176:1 02(158-19 1)
164-1 99(135-189)
14 9-0 71(14 4-154)

27 4:4 19(22 9-31 2)

185:224(159-20 0)

126:239(90-163)

56-331(1 1-9 5)

3 1 :000(3 1)

1 8:0 85(1 2-2 4)

4 3:1 51(2 6-5 0)
4 6:0 78(3 0-4 9)
3 5:1 13(1 7-5 2)

27 4:4 19(22 9-31 2)
31 2 '064(308-31 7)
20 2-3 58(16 2-26 5)
11 8 16 29(2 5-15 9)
1 6:1 34(0 6-2 51

'Usually third or fourth in larvae
-Usually midfin
^The second spine.

fifth or sixth in juveniles

develop strong serrations. Spines in the anterior
preopercular series are much shorter than those in
the posterior series. The second or middle spine is
present only in larvae prior to completion of
notochord flexion. <10 mm. Its appearance as a
spine changes to a small bump which then fuses
with the ridges connecting it to the third preoper-
cular spine of the posterior series- The first and
third anterior spines are present on larvae
through pelagic juveniles of =23 mm and then are
no longer visible-

The superior and inferior opercular spines and
the interopercular spine appear by the time the
larvae reach 12 mm, although percursor bumps
may be seen as early as 9 mm. These spines persist
into the juvenile stage. The subopercular spine is
present in juveniles >78 mm.

Around the eye, the ridge anterior to the post-
ocular spine becomes serrated at 10.6 mm. These

serrations disappear at the time of supraocular
spine formation, >21 mm. The preocular spme
begins to appear in transforming specimens >16

mm and is strongly formed by the time fish are 20
mm. Beneath the eye the second spine of the in-
ferior infraorbital series forms in larvae >10 mm.
The fourth spine of the superior infraorbital series

develops under the posterior third of the eye on
larvae >13.6 mm and it persists through the
juvenile stage as do the two inferior infraorbital
spines. The second and third superior and third
inferior infraorbital spines never develop. Tiny
serrations appear along a ridge between the first
and fourth superior infraorbital spines in speci-
mens 14.4 to 38.2 mm. The first spine of the
superior infraorbital series disappears in speci-
mens >50 mm. The nasal spine develops m larvae
of =10 mm and persists in juveniles.

13

FISHERY BULLETIN: VOL. 77. NO I

T.'\BLE 5. — Measurements (millimeters I of larvae and juveniles o(Sebasles cramen from waters off Oregon. Specimens above dashed

line are undergoing notochord flexion.

55

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23

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1 6

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1 8

4 4

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1 5

1 6

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56

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64

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144

173

93

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3 7

3 1

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1 8

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17 6

9.2

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1 7

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1 7

4 5

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1 6

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82

1 4

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154

18 1

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1 9

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2 1

1 9

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3 7

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M73

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88

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1 7

5174

218

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57

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2 1

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1 9

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21 6

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1 9

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56

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'38 2

46 1

24 3

139

38

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143

103

130

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149

Joined

34

1 2

2 1

62

67

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'569

687

366

184

59

72

5 7

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18 7

166

178

57

92

11 6

216

Joined

48

1 7

26

80

86

80

'468

60 9

312

14 9

34

68

46

40

14 1

120

182

4 1

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103

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Joined

040

17

2,6

66

79

66

'49 2

60 7

32

163

4 7

70

58

40

150

128

160

48

7 1

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192

Joined

34

1 7

26

65

76

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'58 9

73

39 4

21 9

58

83

66

48

195

166

18 1

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84

109

250

Joined

44

2 1

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79

92

74

'630

76 2

41 8

20 8

65

93

72

46

20 5

158

195

59

90

12 5

264

Joined

56

1 7

35

80

100

80

'63 2

77 6

40

21 3

60

94

74

5 1

22 7

18,4

20

66

96

13 3

249

Joined

060

23

32

93

102

84

'65

80 6

40

22 6

66

89

66

49

22 9

184

214

67

_

144

27 4

Joined

38

21

38

85

107

95

'67 6

828

42 8

224

6,2

94

74

49

230

190

21.6

68

102

14,1

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Joined

38

22

36

98

10,2

98

'78 8

96 6

515

30 3

68

130

98

59

27 6

20 7

218

77

98

158

32 3

Joined

40

2 1

48

96

12 5

98

'86 1

105 3

55

33 9

89

14 2

98

7 7

31 4

25 9

229

93

12.6

18,2

352

Joined

46

1 7

53

120

158

120

'918

1123

63 1

36 6

9,3

142

11 2

66

30 9

250

23 8

93

11.5

184

36 8

Joined

60

1 8

59

11 7

14 1

11 7

'94 4

1139

608

33 9

93

128

112

7 1

33

250

24 5

97

12 3

187

35 2

Joined

40

18

57

11 8

12,8

117

'94 7

1147

615

36 2

8 6

152

11 2

75

33.6

26,4

23 7

98

11.8

20,0

40,2

Joined

0.44

19

51

125

144

126

'96 2

118 3

63 4

35 7

84

144

11

7 7

347

277

282

100

13.4

205

41 5

Joined

050

20

57

138

144

13,6

'105 6

128 2

670

41 2

107

163

128

85

38

32 4

288

107

13,6

208

45 2

Joined

044

20

6,8

13 1

15 7

126

'125 7

154 5

80

48 5

123

20

152

91

44.9

35 2

33 3

13 6

155

25 6

47.6

Joined

050

20

72

17 3

19

16,0

'130 5 160 9

86 6

510

133

197

14.9

10 4

46 6

356

373

142

184

28

52 2

Joined

036

1 6

74

163

192

176

'Usually third or fourth in lan/ae. fifth or sixth in juveniles

^Usually midfin

^The second spine

••Not formed

'Transforming.

'Pelagic juvenile

'Benthic juvenile

The tympanic spine, sometimes bifid, appears
on specimens >25 mm. This spine forms at the
anterior edge of a foramen of the cephalic lateral
line system. The pterotic spine is present in flexion
larvae and disappears in juveniles >50 mm. The
supracleithral spine develops in larvae of ~11 mm
and the superior posttemporal spine can be seen on

specimens >18 mm. These latter three spines per-
sist in juveniles, however, the inferior posttem-
poral becomes reduced in larger juveniles. A
cleithral spine develops dorsal to the pectoral fin
base immediately posterior to the opercular mar-
gin on juveniles >30 mm.

14

RICHARDSON and LAROCHE: DEVELOPMENT AND OCCURRENCE OF ROCKFISHES

Scale Formation. — Lateral line pores are visible
on transforming specimens >18.2 mm. Develop-
ing scales are first visible on unstained specimens
=20 mm on the posterodorsal region of the head
and anterodorsal region of the trunk above the gut
cavity. Scale development proceeds posteriorly
with the body being covered by 29 mm.

Pigmentation. — Melanistic pigment on 8.0 mm
specimens of S. crameri (similar to the 9 mm

specimen illustrated) is present on the head over
the brain. Melanophores line the inside tip of the
lower jaw and may also be present along the an-
teroventral margin of the maxillary. In the ab-
dominal region interna! melanophores are dense-
ly concentrated on the dorsal surface of the gut and
more sparsely distributed laterally and ventrally.
Additional external melanophores are present on
the body wall over the gut cavity. A heavy con-
centration of external melanophores and some in-

TABLE 6. — Development of spines in the head region o^ Schastcs crameri larvae andjuveniles. Specimens above dashed line are
undergoing notochord flexion. + denotes spine present and - denotes spine absent.

Standard
length
(mm) Parietal Nuctial

Preopercular
(anterior series)

Preopercular
(posterior series)

Opercular

5tti Supenor Interior cular

Inter-

Sub-

oper-

oper-

Pre-

Supra-

Post-

cular

cular

ocular

ocular

ocular

80

+

-

+

80

+

+

+

90

-f

+

+

90

+

-

+

93

+

+

-

106

+

+

+

106

4-

-f

-f

122

+

-t-

+

126

+

+

+

128

+

+

+

136

+

+

+

138

+

+

+

14 4

+

+

+

14 7

+

+

+

154

+

-1-

+

-'16

-*-

+

+

M63

+

+

+

^173

+

+

-t-

'174

+

-f

+

'182

+

+

+

'184

+

+

+

'18 6

+

+

+

'19.0

-f-

+

-t-

'20-0

+

-1-

+

'203

+

+

+

'21.0

-f

+

■t-

'227

+

+

+

=23-5

+

+

V)

'24-2

+

+

'25-6

+

+

-

'28.6

+

+

-

'30-0

-t-

+

-

'31.8

+

+

-

'357

-*-

+

-

'382

-*-

-f

-

'56 9

+

+

-

M6.8

+

+

-

■•49.2

+

+

-

'58 9

+

-(-

-

"63.0

+

+

_

-63 2

+

+

-

"65

+

+

_

"67 6

+

+

-

"788

+

+

_

"86.1

+

+

-

"91 8

+

+

-

"94.4

+

+

-

"947

+

+

-

"96.2

+

+

_

"1056

+

-f

-

"125 7

^^

+ 5

_

"1305

-i-5

+ S

-

(')

V)

'Bump indicates beginning of spine formation.

^Transtorming

^Pelagic )uvenile

^Benthic juvenile

^Parietal and nuchal spines fused

^Spine IS bifid

15

FISHERY BULLETIN: VOL, 77. NO 1

Table 6.

—Continued.

Infraorbitals

Nasal

length
(mm)

Interior

Superior

Posttemporal <-„p„.

1st 2d

3d 1st

2d 3d

4tfi

Coronal Tympanic Pterotic Superior Interior cleithral Cleilhral

8.0
80
90
90
93

106

106

122

126

128

136

138

144

147

154

'160

'163

'17,3

'174

'182

'18 4

'186

'19.0

'20.0

'20,3

'2'

J22 7

J23,5

>242

325.6

^28.6

'30.0

'31 8

'35.7

'382

'56 9

"46.8

M9 2

■■58 9

'630

■•632

-65

"67.6

'78 8

"86 1

"91 8

"944

"94 7

"96 2

"105 6

"125.7

"130.5

{')

+ +

+ +

+ +

+ +

+ +

+ +

+ +

+ +

+ +

+ +

+ +

(') +

+ +

+ +

+ +

ternal pigment is present in the nape region al-
though the dorsal midline is pigmentless. A few
large stellate melanophores extend laterally from
the nape to the gut cavity. A series of 10 or 11
distinct melanophores is visible along the ventral
midline of the tail, the anterior five of which are
embedded in musculature dorsal to the developing
anal fin. A few small melanophores may be pres-
ent on the notochord tip. The pectoral fins are
distinctively and heavily pigmented. A dense con-
centration of melanophores occurs on the proximal
surface of the fin base but the distal surface is
unpigmented. Elongate melanophores line the
inner and outer surfaces of the fin blades creating

a striated appearance. The developing pelvic fins
are also pigmented.

As larvae develop, pigment increases on the
head over the brain. Melanophores persist along
the tip of the lower jaw and the anteroventral
margin of the maxillary. Several melanophores
develop around the bases of the posttemporal and
supracleithral spines in larvae >10.5 mm and on
the dorsal part of the operculum anterior to the
opercular spines in larvae >13.5 mm.

Pigmentation within the gut cavity remains in-
tense through larval development and external
melanophores remain scattered on the body wall
over the gut. In larvae -10.5 mm, as dorsal fin

16

RICHARDSON and LAROCHE: DEVELOPMENT AND OCCURRENCE OF ROCKFISHES

spines develop, melanophores are added to the
nape patch along the dorsal midline and posteri-
orly along the dorsolateral body surface. The large
stellate melanophores extending from the nape
patch to the gut disappear by 12 mm. A few exter-
nal melanophores appear along the anterior mar-
gin of the middle of the cleithrum beneath the gill
cover in 12 or 13 mm larvae.

In the tail region the ventral midline melano-
phores gradually become embedded, anterior ones
first, and are obscured by overlying musculature
by the time larvae are 13 mm long. A melanophore
is sometimes present near the tip of the notochord.

The pigmentation of the paired fins increases m
intensity throughout the larval period, although
the di.stal base of the pectoral fin remains unpig-
mented. As the pelvic fins develop, melanophores
line the rays giving a striated appearance similar
to that of the pectoral fins.

Melanophores appear on the anterior portion of
the spinous dorsal fin by the time larvae are 11
mm long, and the anterior two-thirds of the fin
remains rather heavily pigmented throughout
larval development. The soft dorsal and anal fins
remain unpigmented.

One to several internal, vertically elongate
melanophores appear at the base of the caudal fin
posterior to the hypural elements on most larvae
>9 mm long, but the fin base is never completely
lined with pigment.

During the transformation period, 16 to 21 mm,
pelagic juvenile pigmentation begins to develop.
On the head, pigment increases around the post-
temporal spines and joins with the nape pigment.
Internal and external melanophores are added on
the dorsal part of the opercle forming a patch
which expands ventrally on specimens >19 mm.
Scattered melanophores appear along the dorsal
surface of the snout and the anterior portion of the
upper lip (internal and external) on specimens
>18.5 mm long. Pigment increases around the
orbit, lining the dorsal, posterior, and ventral
margin of the orbit by 19 mm. In the abdominal
region, an increase in musculature over the gut
cavity obscures the internal gut pigment although
scattered external melanophores persist. The
nape patch extends anteriorly joining the head
pigment, laterally toward the body midline, and
posteriorly to the 12th dorsal spine. Two saddles of
intensified melanistic pigment begin to develop
beneath the first dorsal fin late in the transforma-
tion period. An anterior saddle joins the head pig-
ment and another saddle located midfin expands

ventrolaterally. Melanophores are added dorsally
and ventrally along the anterior margin of the
cleithrum beneath the gill cover, eventually ap-
pearing as a line of pigment. In the tail region,
melanophores appear beneath the middle of the
second dorsal fin in 16 mm specimens. They ex-
pand anteriorly to join the pigment beneath the
spinous dorsal, posteriorly over the caudal pedun-
cle, and laterally towards the body midline ap-
pearing as a saddle by 20 mm. Some melanophores
at the base of the second dorsal fin become concen-
trated along muscles surrounding the dorsal
pterygiophores giving the appearance of vertical
lines of pigment by 20 mm. An additional
melanophore may appear at the point of articula-
tion of each dorsal soft ray 4 through 10 beginning
on 18 mm specimens. Pigment is added internally
and externally along the lateral midline of the
caudal peduncle. On the first dorsal fin pigmenta-
tion increases extending posteriorly to the 1 1th or
12th dorsal spine.

In pelagic juveniles >22 mm long, small
melanophores appear over the surface of the head.
Melanophores almost entirely ring the orbit by 31
mm. Pigment increases on the snout and upper
and lower jaws. The two pigment saddles beneath
the first dorsal fin become more pronounced and
extend moi-e ventrolaterally. A third saddle forms
beneath the first dorsal fin posterior to the first two
in specimens about 22 to 25 mm long. In the tail
region, the saddle beneath the second dorsal fin
extends to the lateral midline by 24 mm and even-
tually reaches the ventral body margin in a 57 mm
specimen. The number of melanophores increases
on the caudal peduncle until dorsal and lateral
pigment are joined forming a fifth pigment saddle
in juveniles about 25 mm long. This fifth saddle
eventually extends to the ventral body margin as
does the saddle beneath the spinous dorsal fin. An
increase in the number of melanophores occurs
along the lateral midline of the caudal peduncle
giving the appearance of a distinguishable, but
not heavy, line of pigment. Small melanophores
are added between saddles 3 and 4 and 4 and 5,
along the myosepta first. The pectoral and pelvic
fins remain heavily pigmented, although the
amount of pigment on the base of the rayed portion
of the pectoral fin decreases. Pigmentation on the
spinous dorsal fin decreases in intensity between
spines III and V, and between spines VIII and IX,
corresponding to areas between the first, second,
and third pigment saddles on the body. On speci-
mens >38 mm long, pigment on the dorsal fin

17

FISHERY BULLETIN VOL 77. NO. 1

above the third saddle darkens into a distinct
black blotch. Melanophores are added to the basal
half of the second dorsal fin above the fourth sad-
dle, appearing continuous with it on specimens
■29 mm long. Melanophores are also added to the
basal half of the anal fin eventually extending
from the second anal spine to the posteriormost
anal fin ray on all specimens >38 mm. Specimens
>36 mm have a melanophore at the point of ar-
ticulation of each soft anal fin ray, although these
melanophores soon become obscured by muscula-
ture and scales. Three to seven small external
melanophores are added near the bases of the
caudal fin rays forming an indistinct line.

Benthic juveniles >60 mm long retain essen-
tially the same melanistic pigment pattern as
pelagic juveniles except the intensity decreases
resulting in a somewhat faded appearance. Addi-
tional light scatterings of melanophores appear in
the lower jaw and gular region, second dorsal and
anal fins, and body in general. Two bars of pigment
radiate ventrally from the posteroventral margin
of the eye. The basic banding pattern and black
blotch at the base of the dorsal fin remain evident
in the largest juvenile, 130 mm, examined. This is
the same banding pattern apparent in adults,
however, the black blotch on the spinous dorsal fin
disappears.

In life (Moser**) a juvenile (122 mm) is reddish-
brown dorsally, with white on the belly and five
brownish bars on the bodv. The first four bars

"H. G, Moser. Fishery Biologist (Research i. Southwest
Fisheries Center. National Marine Fisheries ,Service, NOAA.
P.O. Box 271, La Jolla, CA 92038, pers. commun. 1977.

extend ventrally to slightly below the lateral line
and dorsally onto the dorsal fins as diffuse dark
areas. The head is reddish-brown and pale below
eye level, with three brownish transverse bars:
one at the anterior level of the orbit, one at the
posterior level of the orbit, and one between and
posterior to the parietal ridges. A large spot is on
the opercle dorsally, and the axillary region has a
dusky blotch. Except for the dark bars, the first
and second dorsal fins are dusky at the base, grad-
ing to pale orange or yellowish with Vermillion or
deep red at the margin. The basal half of the anal
and pelvic fins is whitish and the distal half grades
from reddish to dark orange-red at the tips. The
outer pelvic ray has a milky white lateral margin.
The pectorals and caudal fins are pale orange, the
pectorals with dark orange-red tips and the caudal
with a faint dusky band on its posterior half

Occurrence (Figures .5, 6 1. — Sebastes crameri
ranges from Santa Catalina Island off southern
California to the Bering Sea (Miller and Lea
1972). Off Oregon, Washington, and British Co-
lumbia it is primarily an outer shelf/upper slope
species generally occuring in depths of 150 to 300
m (Snytko and Fadeev 1974). Distinct population
clumps have been found off the Oregon coast be-
tween lat. 44°30' and 45°20' N (Snytko and Fadeev
1974). Most of our collections containing young S.
crameri were taken along a transect off Newport
(lat. 44°39.1' N) off the central Oregon coast. The
smallest larvae and the greatest numbers of lar-
vae and pelagicjuveniles were taken at stations 83
and 93 km offshore (water depths 700-1,300 m).
The nearest inshore station on this transect at

L-

•

r

•r

L

^»

h

Pelagic Juveniles

1 . .

■-■ ^1 ^i ^1 'i

V*™""" *'.

;

^*\

Lil*

r

H

:

A„^

Benthic

Juveniles

/ -:.. :

- "i -

\ ^1

V~-— ,.|

FlOURE 5. — Number of specimens and location of capture oflarvae and juveniles ofSehnstes crameri ofTOregon ( 1961-75) described in

this paper.

18

RICHARDSON and LAROCHE: DEVELOPMENT AND OCCURRENCE OF ROCKFISHES

MAR

40 60 eO 100

Stondofd Length (mm)

20 140

Figure 6. — Seasonal occurrence of larvae and juveniles of
Sebastes cramen off Oregon. Data from 1961 to 1975 combined.
Dashed line separates pelagic and benthic stages.

which a larva (15.7 mm) was taken was 28 km
(depth 95 m). The farthest offshore occurrence on
this transect was a 26 mm pelagicjuvenile 194 km
offshore. Benthic juveniles were generally taken
nearer to shore than larvae or pelagic juveniles at
depths of 55 to 200 m. Most pelagic specimens
came from Isaacs-Kidd midwater trawls towed
obliquely through the water column. Four speci-
mens, 17.7, 24.0, 38.2, and 56.9 mm, were collected
in a neuston net in June, 56 to 65 km off Newport.
Spawning times reported for S. crameri are
November through March off California (Phillips
1964) and primarily February off Oregon,
Washington, and British Columbia (Westrheim
1975; Westrheim et al. see footnote 7). However,
mature females with ovaries containing embryos
have been collected in February, March, ,'\pril.
and June (Westrheim et al.,^ see footnote 7; Mar-
ling et al.'"). Pelagic specimens in our collections
were taken primarily in April, May, and June
although two postflexion larvae were taken in
August. Larvae under 10 mm were only taken in
April and May. No specimens were taken Sep-
tember through February. Because of a lack of
information on larval growth, parturition time

'Westrheim. S. J.. W R. Harling, D, Davenport, and M. S,
Smith. 1968. Preliminary report on maturity, spawning sea-
son, and larval identification of rockfishes iSeicstorfcsl collected
off British Columbia in 1968- Fish, Res. Board Can.. Manuscr
Rep. 1005, 28 p,

'"Harlmg.W. R.. M.S. Smith, and N, A, Webb. 1971. Pre-
liminary report on maturity, spawning season, and larval iden-
tification of rockfishes iScorpaenidae) collected during
1970. Fish. Res. Board Can. Manuscr. Rep. 1137, 26 p.

cannot be inferred. The wide range of lengths of
pelagic specimens, 8 to .30 mm in April, 9 to 36 mm
in May, 18 to 57 mm in July, indicates spawning
may be variable and protracted. Benthic juveniles
were taken March through July.

In trawl surveys off Oregon, adults ranked sec-
ond in biomass only to S. diploproa of all
rockfishes collected over the continental slope and
fifth or sixth on the continental shelf (Demory et
al. 1976). Snytko and Fadeev ( 1974) reported it to
be one of the most abundant trawl-caught rockfish
species over the slope together with S. alutus, S.
saxicola, and S. diploproa. This species was one of
the three major contributors to the 1963-71 Ore-
gon landings of the Pacific ocean perch fishery
exceeding ,S. alutiis in 1971 (Niska 1976). Al-
though little can be said about the actual abun-
dance of larvae and juveniles off Oregon because of
the various kinds of samples examined and irregu-
lar nature of the sampling effort, they were one of
the more common kinds relative to the other
species of Sebastes in the samples.

SEBASTES PINNIGER (GILL)

(Figures 7, 8, 9)

Literature. — Pigmentation of preextrusion larvae
of S. pinniger was listed in tabular form by Wes-
trheim (1975). Newborn to 2-wk-old larvae were
described by Waldron (1968) and the older larva
was redrawn by Moseretal. (1977). Mean length
of larvae at hatching is 3.6 mm SL. Newborn lar-
vae have an irregular double row of pigment (usu-
ally <16 melanophores) along the ventral midline
between the 18th and 22d myomere and some
pigment above the yolk sac near the anus. After 2
wk additional melanophores are present at the tip
of the lower jaw, on the ventral part of the yolk sac,
on the pectoral fins, along the dorsal midline in an
irregular double row between the 19th and 21st
myomeres, and in the hypural region. The ventral
midline melanophores may extend as far forward
as the 14th myomere.

Identification (Table 7, Appendix Tables 2-6).— A
total of 269 specimens of S. pinniger, 7.9 to 181
mm long, were identified. Juveniles were iden-
tified using the following combination of charac-
ters compiled from specimens in our collections:

Gill rakers = 40-45, left arch; 38-46, right arch

Lateral line pores = 40-45

Pectoral fin rays = 16-18, usually 17

19

FISHERY BULLETIN VOL 77. NO 1

8.9 mm

9.8 mm

I4.lmm

Figure 7.— Planktonic larvae (8.9. 9.B mm.l and transforming specimen (14.1 mm) of Sebastes pinniger.

20

RICHARDSON and LAROCHE: DEVELOPMENT AND OCCURRENCE OF ROCKFISHES

16.2 mm

20.0 mm

29.4 mm

Figure 8. — Transforming specimen 1 16.2 mmi and pelagic juveniles i20.0, 29.4 mm) of Sebastes pinniger.

21

FISHERY BULLETIN VOL, 77. NO 1

40 mm

59.4 mm

Figure 9. — Pelagic juvenile (40.0 mm) and benthic juvenile (59.4 mm) of Sehastes pinniger.

Anal fin soft rays = 7

Dorsal fin soft rays = 13-15, usually 14 or 15

Supraocular spine = present

Interorbital space = flat to convex.

Large juveniles ( >26 mm SL) have the black
blotch at the base of the posterior half of the spi-
nous dorsal fin characteristic of adults. Other
Sebastes juveniles which have a black blotch, e.g..
S. nu'lanops, S. //ac/f/w.s, S. cranieri, do not agree
with the characters given above. Of the Sebastes
species occurring off Oregon, S. pinmger has the
best fit to all these characters. Sebastes rmniatus
and S. emphaeus also agree with many of the
counts. However, juvenile S. iiiiniatus and S. em-

phaeus lack a black blotch at the posterior base of
the spinous dorsal fin. Sebastes mtniatus usually
has 18 rather than 17 pectoral rays, and S. em-
phaeus lacks supraocular spines. The larvae and
juveniles in the series in question were among the
most abundant in our collections. Adult S. pin-
niger are known to be abundant in trawlable areas
offshore whereas S. miniatus are not commonly
taken (Demory et al. 1976; Niska 1976). Sebastes
emphaeus, although not previously reported from
Oregon, is well represented in our samp'es. Fig-
ment pattern, general body shape, time of occur-
rence, and constancy in number of anal fin soft
rays and pectoral rays helped link the dev iop-
mental series together.

22

RICHARDSON and LAROCHE: DEVELOPMENT AND OCCURRENCE OF ROCKFISHES

Table?. — Meristics from larvae and juveniles of Se6as/espmni^<>r off Oregon, based on unstained specimens. Specimens above dashed
line are undergoing notochord flexion. All specimens had 8 superior and 7 inferior principal caudal fin rays and 7 branch iostegal rays on
each side.

standard
length
(mm)

Dorsal
fin spines
and rays

Anal
fin spines
and rays

Pectoral
fin rays

Pelvic fin
spines and rays

Left Rigtit

Gill rakers
(first arcti)

Lateral
line pores

Diagonal
scale

Left Riglit

Left Rigtit

Left Right

rows

78
78

CI

— f7
17 —

M') IV)

— —

— —

—

88

Vllltl=.14

III5.7

8.9

IX^IMS

IIIJ.7

93

XIIP,14

IIP.7

98

XIIP,14

IIP.7

107

XIII3.14

IIP,7

107

XIIIMS

ll|5,7

109

XIIIM5

IIP,7

123

XIIP.15

IIIJ.7

12 3

XIIIM4

1IP.7

■■128

XIII3.15

IIIJ.7

M30

XIIP,14

IIP.7

'14 1

Xll|5,14

IIP. 7

"142

XIIP.U

lll'.7

■■152

XIIIM5

lll'.7

"160

XIIIM4

IIP.7

"160

XIIIM4

III5.7

"162

Xll|5,15

IIP7

"168

Xll|5.t4

IIIJ.7

"178

XIII5.15

IIP.7

"18 4

XIM5.14

IIP.7

M86

XIII, 16

III.7

^■189

XIII.IS

III.7

M94

XIII.IS

111,7

5195

XIII.14

111,7

520

XIII.14

III.7

520 8

Xlll,14

111,7

522 4

XIII.14

III.7

523 4

XIII.14

111,7

526 4

Xlll,14

IM.7

526 4

XIII.14

III.7

526 6

XIII.IS

III.7

528 6

XIII.14

III.7

528 8

XIII.15

III.7

529 4

XIII.14

III. 7

530 4

XIII.13

III.7

530 9

Xlll,14

111,7

534 1

XIII.14

III.7

538

XIII.14

III.7

538 7

XIII.IS

111,7

5392

XIII.14

'11.7

5400

XIII.14

l'l,7

541

XIII.14

.117

542 4

XIII.IS

111,7

5594

XIII.14

111,7

5117 7

Xlll,14

111,7

5181

XIII.IS

III.7

17
17
18
17
17
17
17
17
17
17
17
17

17
17
17
18
17

18

17
17
17
17
17
17
17
17
17
17
17
1-
16
17
17
17
17
17
1;
17
17
17

17
17
17
17
17
17
17
17
17
17
17
17

17
17
17

17
17
18
17
17
18
17
17
17
17
17
17

17
17

■7
17

17
17

I.S
IS
1.5
I.S
1,5
1,5
IS
1.5
I.S
1.5
I.S
1,5

1.5
15
1,5
1,5
1,5
I.S
I.S
1.5
IS
1.5
1,5
1.5
1.5
I.S
1.5
1,5
1.5

1 ;
i.f

I.S
1.5
1,5
1.5

1.5
1.5
15
l.i
1.5
1.5
I.S
1,5
1.5
1,5
1,5

1,5

—

—

—

IS

—

—

—

1.5

_

_

—

1.5

—

—

—

I.S

—

—

—

1,5

—

—

—

1,5

—

—

—

1,5

—

—

—

I.S

—

—

—

I.S

-~

—

—

1.5

—

_

—

1.5

—

27- 12 or 13
= 39 or 40

—

1,5

—

—

—

1,5

—

—

—

1,5

—

28+13=41

—

1,5

—

—

—

1,5

—

27 + 13=40

—

1.5

—

_

—

I.S

—

27 + 12 = 39

—

I.S

—

—

—

1,5

27-14=41

28-14=42

—

1.5

29-13=42

28-13=41

_

1,5

27*13=40

26' 12-38

—

1,5

27-13=40

27-12 39

—

1,5

27-14=41

28-13-41

44

1,5

28-13=41

28-13=41

—

I.S

28-13 = 41

29-13=42

_

IS

29*13=42

28-14=42

-44

1.5

29+15=44

29 + 14 = 43

-43

I.S

28- 14=^42

2d -13=41

—

1,5

28-13 = 41

29 + 14=43

—

IS

28-13=41

29*14 = 43

»42

IS

29-13 = 42

28-13 41

—

1.5

28- 13 = 41

28 + 14=42

-44

1.5

28-13 = 41

28 + 13 41

«44

1.5

31 14 = 45

31 + 15-46

—

1,5

29-14=43

29 + 14=43

.44

l,S

28*14 = 42

29 + 14=43

—

1,5

27-13 = 40

29+i:.=42

=42

1,5

29-14=43

29+1 4 43

=41

1.5

28 + 14=42

29 + 13=42

40

1,5

30-14=44

30-1- 44

—

I.S

29-14 = 43

29-14 = 43

1,5

29-14=43

29-14 = 43

:.,_

l,S

29-14 = 43

29- 13-42

45

1.5

30-14=44

28-14=42

43

=44
=40

x44
«42
«44

=41

43
40
43
44
43

=51
=50

'Forming

^Not formed

^Postenormost dorsal or anal spine appears as a soft ray

"Transforming

5Pelagic luvemle

5Benthic juvenile

Distinguishing Features. — Characters useful in
distinguishing the smallest larvae (7.8 mm) of S.
pintager identified from our collections are the
presence of remnants of both dorsal and ventral
midline melanophores the anterior of which are
nternal, the lightly pigmented pectoral fins,
melanophores at the tip of the lower jaw and on the
anteroventral margin of the maxillary, the pres-
ence of one or two large external stellate melano-
phores on the (i- sum just posterior to the parietal

spines, the relatively deep body (40'7f SL), long
parietal spines (24'^f HL), and long pectoral fins
(25% SL). Later stage larvae are characterized by
their relative lack of pigment on the trunk except
over the gut, together with the relatively deep body
and long parietal and third posterior preopercu-
lar spines. Meristics, presence of the supraocular
spine, flat to convex shape of the interorbital
space, and dark blotch at the base of the spinous
dorsal serve to distinguish the juveniles.

23

FISHERY Bl'M-ETIN VOL 77. NO. 1

General Development. — The smallest larvae of S.
pinniger identified, 7.8 mm, are in the final stage
of notochord flexion. By the time larvae are 8.8
mm long, fle.xion is complete. Transformation to
pelagic juvenile begins in larvae -12.5 mm long
with the initiation of spine formation in the dorsal
and anal fin "prespines" and the appearance of a
patch of melanophores on the dorsum immediately
posterior to the second dorsal fin. Transformation
of the "prespines" to spines is complete in speci-
mens > 18.6 mm and some pigment has been added
beneath the first dorsal fin marking the beginning
of pelagic juvenile pigmentation. The dorsal pig-
mentation becomes more pronounced during the
pelagic juvenile period which lasts until ~40 to 50
mm. The largest pelagic juvenile taken was 42.4
mm and the smallest benthic juvenile was 59.4
mm.

Morphology (Tables 4, 8). — Forty-eight specimens
of S. pinniger. 7.8 to 181.0 mm long, were mea-
sured for developmental morphology. Larvae ap-
pear quite deep bodied, but body depth at the pec-
toral fin ba.se decreases considerably during the
pelagic period from 40 to 33'r SL. In comparison,
body depth at the anus/SL changes relatively lit-
tle, decreasing slightly then increasing. Snout to
anus length increases from 59 to 64'^( SL while
snout to pelvic fin distance increases to a lesser
degree.

Head length decreases from 43 to 37*^^ SL during
development as more marked changes occur in eye
diameter, decreasing from 37-39 to 27'r HL, and
interorbital distance, decreasing from 37 to 20Cf
HL. Upper jaw length/HL first decreases and then
increases while snout length/HL increases then
decreases. The length of the angle gill raker in-
creases with respect to head length from 1 1 to 14 or

15'7f.

Larvae and young juveniles up to 24 mm have a
prominent symphyseal knob directed anteroven-
trally. It becomes less obvious with development
and is barely noticeable by the time juveniles are
29 mm long.

Fin Development (Tables 4, 7, 8). — Pectoral fins
are present and the adult complement of 16 to 18
(usually 17) rays can be counted in 7.8 mm larvae
of S. pinniger. although the ventral rays are not
fully formed until >8 mm. The pectoral fins are
relatively long in flexion and postflexion larvae
averaging 2.5''( SL and they maintain this approx-
imate proportion through development. Depth of

24

the pectoral fin base decreases from 15 to 9'/f SL.

Developing pelvic fins are visible on 7.8 mm
larvae and the adult complement of I, 5 is count-
able in postflexion larvae of 8.8 mm. The pelvic
fins are rather long, averaging 14'^f SL in flexion
larvae and increasing to a maximum of 23'^f SL in
transforming specimens. Length of the pelvic
spine, always less than the fin itself, increases
from 5^'<- SL in flexion larvae to 2Cf( in transform-
ing specimens then decreases to 1.3''f in benthic
juveniles.

The adult complement of principal caudal rays
can be counted in 7.8 mm larvae, before the com-
pletion of notochord flexion at 8.8 mm. Counts of
secondary caudal rays were 11 superior and 12
inferior rays on each of two stained juveniles, 29.5
and 33.4 mm.

Bases of some of the dorsal and anal fin ray and
spine elements are visible on the 7.8 mm larvae.
The adult complement of ray and spine elements is
present in postflexion larvae >9 mm and the rays
and spines (with "prespines") appear fully formed
by 9.3 mm. Transformation of "prespines" to
spines is completed by 18.5 mm. The longest dorsal
spine increases from 20 to 38'? HL during the
pelagic period. The longest dorsal ray increases
from 32 to 42 or 439*^ . The longest anal spine in-
creases from 19 to 37'7( HL during pelagic de-
velopment.

Spmation (Tables 4, 9). — Spines present on the
left side of the head of the two smallest specimens
of S. pinniger, 7.8 mm, include the parietal; the
nuchal; the first and third anterior preopercular;
the second, third, and fourth posterior preopercu-
lar; the postocular, the pterotic, the inferior post-
temporal; the first spine of the inferior infraorbital
series; and the first spine of the superior infraorbi-
tal series.

The parietal spine and ridge are heavily and
relatively deeply serrated in small larvae and the
spine is relatively long, averaging 24'f HL in flex-
ion larvae. Its relative length decreases with de-
velopment to 20^7^ HL in flexion larvae, 10^ in
transforming specimens, and 77c in early pelagic
juveniles, <20 mm. The much smaller nuchal
spine averages 4 or 57r HL in postflexion and
transforming larvae, decreasing to 19f in benthic
juveniles. The parietal and nuchal spines fuse to-
gether, beginning in pelagic juveniles -20 mm
until only the nuchal tip is visible in juveniles >40
mm. Serrations along the parietal ridge can be
seen on specimens up to 39 mm.

RICHARDSON and LAROCHE: DEVELOPMENT AND OCCURRENCE OF ROCKFISHES

Table 8. — Measurements (millimeters) of larvae and juveniles of Sebastes pinmger from waters off Oregon. Specimens above

dashed Ime are undergoing notochord flexion.

o —
t-

£
en
c

li

S

O)

0) —
I

O OJ

c —
CO

S
(U c

E

ra

»-□

UJ

Is

£•5
c

ra _

n O 0)

c
m£

Q-

C Q.

is

CL

h

<D —

a.

HO,
Q.

c
CO

2g&
a.

Q.

OJ CJi

a c

z

3
U

55 miE

Q.C Ol

O ClC

5)

g'&«!
<

O Q)

>-
111
3

c

o

-t

78

98

4.6

3-3

0.88

1,6

12

1 2

32

2 1

21

1 1

40

1 2

3.4

0.80

(')

1 2

—

(*)

(')

(')

78

95

45

3.4

0.92

1 6

13

1 3

3 1

22

1 8

1 2

C)

96

30

084

C)

1 1

—

(^1

(»)

..........

88

11 2

55

42

1

22

1 5

1 4

37

25

2 1

1 2

72

88

36

—

_

1 2

_

_

1

8.9

11 1

46

34

92

1 4

1 4

1 3

30

22

1 8

1 2

88

1 1

34

76

016

1 2

—

46

1 1

(=)

93

11 5

56

40

1 3

1 9

1 5

1 4

35

26

2 1

1 2

1 2

1 4

38

94

10

1 4

—

52

1 1

{')

98

123

58

4 1

1 2

1 9

1 6

1 5

38

30

2 7

1 2

—

1 7

34

96

18

1 6

34

—

1 3

60

107

14 1

66

4 7

1 3

22

1 9

1 6

43

32

27

1 4

—

1 9

48

—

—

—

054

1 1

1 5

1

107

134

63

46

1 6

20

1 9

1 4

39

29

27

1 3

1 6

23

4 7

—

—

1 2

48

1

1 4

88

109

128

63

45

1 2

22

1 8

1 5

43

33

—

1 4

1 6

20

44

—

—

1 5

44

92

1 4

84

123

155

77

50

1 3

2 1

1 9

1 7

4 4

34

30

1 4

—

24

4 9

44

18

1 6

56

—

1 9

1

123

154

76

52

1 6

—

2 1

1 7

48

3 7

35

1 4

—

28

52

—

36

1 3

64

1 5

1 9

—

'128

157

80

52

1 9

2 1

20

1 6

4 5

34

29

1 3

24

27

59

66

18

1 3

70

1 5

1 6

1 3

'130

152

82

55

1 7

2 1

2 1

1 6

4 8

3 5

35

1 5

—

27

59

60

30

1 6

68

1 3

20

1 1

'14 1

17 1

85

59

21

21

22

1 7

49

35

—

1 5

26

30

60

68

32

1 3

68

—

—

1 5

'142

168

86

57

1 6

—

22

1 8

5 1

39

—

16

25

30

58

—

36

1 3

72

1 7

22

1 5

'152

192

9 1

62

1 9

28

23

20

54

4 3

43

1 7

3 1

3 7

62

80

40

1 5

84

1 9

24

1 8

'160

20

94

62

1 7

28

24

20

59

4 5

45

1 8

—

38

62

—

28

1 4

80

24

—

20

'160

208

93

66

1 7

31

25

20

57

4 5

4 5

1 6

—

—

62

26

18

1 4

088

—

24

1 7

'16.2

20 6

102

69

1 9

32

26

20

62

50

5 1

1 8

—

4 1

6 7

—

50

1 6

90

28

29

—

'166

197

10 1

67

2 1

28

2 5

1 9

63

4 7

4 5

1 8

—

—

65

—

34

1 6

88

22

25

—

'178

20 8

107

70

22

28

27

20

64

52

48

1 8

36

4 1

76

—

—

1 6

090

—

28

—

'184

21 8

107

70

1 9

28

25

22

64

5 1

4 4

20

40

4 4

75

72

16

1 6

94

—

30

27

«186

22 9

11 7

76

23

33

26

20

62

4 7

50

1 8

36

42

86

70

32

—

1 1

26

32

26

«189

23 5

11 7

7 7

24

33

2 7

2 1

64

48

—

1 9

36

4 1

84

—

—

1 6

09

—

—

24

"194

23 4

11 2

80

19

34

27

22

66

54

52

1 9

4 2

46

76

46

30

1 7

1 1

—

31

26

"195

24 6

115

82

22

3 5

28

22

67

52

—

20

43

46

66

84

44

1 4

1

30

—

2 7

"20

25 4

11 5

74

1 8

34

28

22

74

56

5 7

20

—

46

80

40

30

—

1 1

—

32

28

"20 8

24 8

126

80

26

3 1

28

21

70

53

59

20

39

42

85

Joined

32

1 2

1 2

—

—

27

•22 4

26 7

130

84

20

34

30

23

7 7

59

60

22

45

52

80

Joined

26

1 4

1 2

—

—

32

'234

28 8

13 1

78

2 1

3 7

33

24

80

63

6 1

2 1

4 7

5 1

77

Joined

28

—

1 2

36

38

33

"26 4

33 4

15.2

9 1

2 1

4 2

35

26

89

70

73

25

—

60

99

Joined

40

1 4

1 5

—

40

40

"26 4

312

173

104

34

40

34

24

89

70

72

24

46

55

120

Joined

20

1 2

1 5

—

—

32

"26 6

32

170

10 6

26

42

34

22

89

7 1

7 1

24

48

6 1

109

Joined

40

—

1 4

—

—

36

"28 6

38 1

179

107

30

40

35

27

92

73

76

26

—

64

1 1 4

Joined

28

1 3

1 5

—

42

4 1

•28 8

36 3

192

106

34

43

3 7

26

96

76

76

26

52

62

13 1

Joined

30

1 2

1 5

40

4 1

4 4

"29 4

37 1

179

10 1

26

4 1

37

27

105

80

7 5

28

52

66

107

Joined

28

1 2

1 6

44

4 4

4 4

"30 4

38 1

20 5

11 5

3 7

49

3 7

26

10 1

7 5

7 7

25

52

65

134

Joined

—

1 2

1 6

44

4 4

4 4

"30 9

38 6

20 8

130

4 1

45

40

27

104

81

86

28

55

72

134

Joined

—

1 2

1 6

46

46

—

"34 1

42 6

22 7

125

39

53

4

27

11

83

—

28

5 7

66

155

Joined

34

1 5

1 6

4 4

48

48

"38

46 6

22 5

138

30

57

4 7

30

11 6

9 1

93

31

—

7 7

14 1

Joined

30

1 3

1 9

49

57

53

"387

46 4

23 4

133

33

60

4 5

29

120

98

96

34

66

78

142

Joined

46

1 4

2 1

54

—

—

"39 2

48 8

23 5

139

32

59

4 5

30

11 7

10 1

102

33

57

80

146

Joined

30

1 3

1 9

—

6 1

53

"40

49 1

23 5

149

36

60

4 7

33

12 5

104

96

36

65

88

155

Joined

30

1 4

2 1

53

66

63

"41

50 4

25

14 7

43

59

46

31

122

98

104

34

63

84

178

Joined

30

1 5

2 1

56

66

55

■42 4

51 7

26 4

154

4 3

5 7

49

30

130

11

102

37

64

87

165

Joined

40

1 4

2 1

51

63

52

»59 4

71

36

21 8

64

93

66

40

194

162

136

51

74

11 3

24 4

Joined

46

1 4

30

7 4

89

75

'1177

141 8

78 3

43 8

125

195

11 2

86

41 6

33 2

29 4

10 1

148

25 5

48 3

Joined

64

1 7

66

138

174

142

»181

224

1172

65 4

18 1

30 6

159

137

67 2

61 5

45 1

163

218

41 2

83 5

Joined

70

2 3

106

26 7

30 9

23 9

'Usually third or fourth in larvae, fifth or sixth in juveniles

^Usually midfin

^The second spine

*Bump

^Not formed

^Forming

'Transforming

"Pelagic juvenile

'Benthic juvenile

The posterior series of preopercular spines are
prominent in S. pinmger larvae. The heavily ser-
rated third spine is relatively long averaging 32
to 34'7( HL in flexion and postflexion larvae. Its
relative length then decreses to 5^f in benthic
juveniles. All five spines of the series are present
in larvae >10 mm. Serrations are visible on the
second, third, and fourth spines until =29 mm.

The first posterior preopercular spine is some-
times bifid in pelagic juveniles. The smaller first
and third spines of the anterior preopercular
series are also conspicuous on small larvae, but
decrease in prominence until they are no longer
visible in pelagic juveniles >26 mm. The second
anterior preopercular spine never becomes appar-
ent.

25

FISHERY BULLETIN: VOL, 77. NO. 1

The superior opercular spine is present on lar-
vae by 9 mm and the inferior opercular spine ap-
pears later in larvae —12 or 13 mm. Both spines
are present on juveniles. An interopercular spine
develops on the edge of the gill cover, usually in
larvae >10 mm. A subopercular spine was not
present on any of the specimens examined.

The ridge anterior to the postocular spine is
heavily serrated and remains so until preocular
spine formation. The preocular appears first as a
bump in transforming larvae =16.0 mm long and
develops into a spine in pelagic juveniles >19 mm.

Development of the supraocular follows a similar
pattern appearing at about the same time as the
preocular. Beneath the eye the fourth spine of the
superior infraorbital series is present in larvae >9
mm and the third spine of this series is present in
all larvae >13 mm. The second superior infraorbi-
tal spine never forms. All three superior infraorbi-
tal spines disappear by 43 mm. The second spine of
the inferior infraorbital series is present on speci-
mens >10 mm and the two spines in this series
persist in juveniles. The third inferior infraorbital
spine never develops. The nasal spine develops

T.^BLE 9. — Development of spines in the head region of Sebastes pinniger larvae and juveniles. Specimens above dashed line are
undergoing notochored flexion. + denotes spine present and - denotes spine absent.

88
8.9
9.3
9.8
10.7
10.7
10.9
12.3
123
M2.8
'13.0
'14 1
'142
'15.2
'160
'160
'16.2
'16.8
'178
'18 4
'186
M8.9
J 19.4
M9.5
=20.0
■1208
=22.4
123 4
'264
=26.4
=26 6
=28.6
=28.8
=29.4
=30 4
=30.9
=34.1
=38.0
=387
'39.2
=40.0
'41
=42.4
«594
*117.7
6181

Standard
length

Parietal Nuchal

Preopercular
(anterior series)

1st 2d 3d

Preopercular
(posterior series)

Opercular
Superior Inferior

Inter-
oper-
cular

Sub-
oper-
cular

Pre- Supra-
ocular ocular

Post-

{mm)

1st

2d 3d 4th

5th

ocular

7.8
78

» +

+ - +
+ - +

-

>- -- +

~

~

"

~

-

4

+ +

{')

4-

4-

i')

{')

+

-

+

+

(')

+

+

i')

f

4

{')

(')

{')

(^)

n

(')

+ +

+ +

'Transtorming,

-'Bump tndicates beginnrnq of spine formation

^Pelagic luvemle

■'Spine IS bifid

^Parietal and nuchal spines fused

■^Benthic juvenile

^Spine has become rounded, no sharp tip

26

RICHARDSON and LAROCHE: DEVELOPMENT AND OCCURRENCE OF ROCKFISHES

Table 9.— Continued.

Infraorbitals

Nasal

Posttemporal
Coronal Tympanic Rerotc Superior Interior

Standard
length
(mm)

Inferior

Supenor

Supra-

1st

2d

3d

isl

2d 3d

4th

cleithral Cleithral

78
78

4-

-

-

-

-

-

— — + - +

- - + - +

-

8.8

+

-

8.9

+

-

9.3

+

-

9-8

+

-

10,7

+

+

10.7

+

+

10.9

+

+

12.3

-f

+

12.3

+

+

M2.8

+

+

•13.0

+

+

'14.1

+

+

M4.2

+

+

M5.2

+

+

M6.0

+

+

M6.0

+

+

'16.2

+

+

'16.8

+

+

'17.8

+

+

'184

+

+

318.6

+

+

318-9

+

+

319.4

+

+

319.5

+

+

320.0

+

+

320-8

+

+

3224

+

+

323.4

+

+

326.4

+

+

326.4

+

+

326,6

+

+

328.6

+

+

328.8

+

+

329,4

+

+

330-4

+

+

330.9

+

+

334.1

+

+

338.0

+

+

338,7

+

+

339.2

+

+

340.0

+

+

341.0

+

+

342,4

+

+

659.4

+

+

61177

+ ^

+

M81

+ '

+

7

{')

+ +

+ +

+ +

+ +

+ +

+ -I-

(^1

first as a bump in larvae >9 mm and is present in
juveniles.

The tympanic spine appears on specimens >35
mm SL. This spine forms at the anterior edge of a
foramen of the cephalic lateral line system. The
pterotic spine, present in the smallest larvae, dis-
appears in benthic juveniles. The supracleithral
spine develops posterior to the inferior post-
temporal on larvae >9.5 mm and the superior
posttemporal spine is present dorsal to these in
specimens >14 or 15 mm. This latter spine is occa-
sionally bifid. The inferior posttemporal disap-
pears in benthic juveniles. Posterior to the opercle
the cleithral spine is visible in pelagic juveniles of
19.5 mm and persists in benthic juveniles.

Scale Formation . — Lateral line pores are visible
on specimens >17 mm. Scale formation has begun
on juveniles >23 mm.

Pigmentation . — The smallest larvae of S. pinniger
examined, 7.8 mm (similar to the 8.9 mm speci-
men illustrated), have pigment on the head over
the brain. Melanophores line the inner tip of the
lower jaw and a few are present along the antero-
ventral margin of the maxillary. In the abdominal
region, an internal melanistic shield covers the
dorsal half of the gut, appearing darkest on the
dorsal surface. A few additional melanophores are
present along the ventral midline of the gut cav-
ity. Two or three lai-ge stellate melanophores are

27

FISHERY BULLETIN: VOL. 77, NO, 1

on the dorsum immediately posterior to the
parietal spines. In the tail region several embed-
ded melanophores, sometimes fused, are on the
dorsal and ventral body midlines near the caudal
peduncle. These midline melanophores are pres-
ent in the same region as the midline pigment
shown on Waldron's (1968) reared 2-wk-old lar-
va. The pectoral fin blades are lightly pigmented
with elongate melanophores. Melanophores are
also present on the inner side of the pectoral fin
base but not on the outer side. The pelvic fins also
have a light scattering of melanophores. The
caudal fin base is unpigmented.

During larval development, pigment increases
on the head over the brain. Occasionally one or two
melanophores are present on the snout. Melano-
phores lining the inner tip of the lower jaw and
those on the anteroventral margin of the maxil-
lary remain throughout the larval period.

The melanistic shield over the gut intensifies
laterally and melanophoreson the ventral midline
disappear. The two to three stellate melanophores
on the dorsum posterior to the parietal spines dis-
appear by the time larvae are 9 mm long.

In the tail region, the dorsal and ventral midline
melanophores near the caudal peduncle are no
longer visible on larvae >9 mm.

The rayed portions of the pectoral and pelvic fins
remain lightly pigmented during the larval period
but melanophores are no longer present on the
inner side of the pectoral fin base in larvae >10
mm.

During the transformation period, 12.8 to 18.6
mm, the amount of pigment increases gradually.
In the head region, internal pigment is added to
the opercle dorsally until a patch of 6 to 10
melanophores is visible on specimens >16 mm.
Internal gut pigmentation decreases in intensity
due to overgrowth by musculature. A few melano-
phores sometimes appear on the nape and beneath
spines V to XI of the first doral fin, although not
consistently until late in the transformation
period in specimens >17 mm. The most prominent
addition of pigment occurs dorsally in the tail re-
gion just posterior to the soft dorsal fin. Melano-
phores are added along the dorsolateral surface of
the caudal peduncle. Directly below these
melanophores, three or four internal and one to
four external melanophores are added along
the lateral midline in specimens >15 mm. The
amount of pigment on the pectoral and pelvic fins
decreases during this period.

During the pelagic juvenile period, 18.9 to 42.4
mm, new pigment is added over the dorsal surface
of the head, interorbital, snout, premaxillary
(specimen >26 mm), and on the lower jaw (speci-
men >35 mm). The opercular patch enlarges.
Around the eye, melanophores are added first on
the posteroventral margin of the orbit in speci-
mens 19 to 23 mm, and eventually line the orbit. A
radiating bar of melanophores begins to extend
from the posteroventral margin of the orbit on
specimens >28 mm, extending onto the preopercle
on specimens -30 mm. In the abdominal region,
melanophores are added dorsolaterally to the nape
and beneath spines V to X of the first dorsal fin
forming two pigment patches connected by a dor-
sal row of melanophores by 23 mm. The nape patch
expands forming a saddle ( first in position) extend-
ing from the parietal spine to the third dorsal
spine and ventrally to the superior posttemporal
spine by 28 mm. Two saddles (second and third)
develop from the pigment patch beneath the spi-
nous dorsal fin, midfin beneath spines IV to VI and
posteriorly beneath spines VIII to XI. These two
saddles are separated by a relatively unpigmented
area on the dorsum. As they extend more ven-
trolaterally, they fuse together in two places just
above and below the lateral line creating a second,
circular, less pigmented area on specimens >39
mm. These two saddles eventually extend to the
dorsal portion of the gut cavity by 42 mm. A single
external melanophore may occur on the midan-
terior margin of the eleithrum beneath the gill
cover. In the tail region, the dorsal patch of pig-
ment on the caudal peduncle extends to the lateral
line forming another saddle by 23 mm which
reaches the ventral body margin by 27 mm. Be-
neath the second dorsal fin melanophores increase
in number and become concentrated along the
muscles surrounding the dorsal pterygiophores
appearing as vertical lines of pigment by 23 mm.
Melanophores also develop at thepoint of articula-
tion of all but the anteriormost three or four dorsal
soft rays. A melanistic saddle (fourth in position)
develops beneath soft dorsal rays 3 to 12 or 13
extending ventrolaterally to the body midline by
34 mm and three-fourths the distance to the ven-
tral margin by 42 mm. The pectoral and pelvic fins
are no longer pigmented in specimens >21 mm
Pigment develops on the first dorsal fin membrane
between spines IX and XI in juveniles '26 mm,
eventually forming the "black blotch" characteris-
tic of larger juveniles and adults. Melanistic bars
form on the first dorsal fin between spines I to III

28

RICHARDSON and LAROCHE DEVELOPMENT AND OCl'URRENCE OF ROCKFISHES

and V to VIII above the first and second saddles.
By 39 mm the outer half of the fin is completely
pigmented, while two unpigmented areas remain
on the proximal half of the fin between the two
pigment bars. Melanophores are added on the sec-
ond dorsal fin above the fourth saddle until the
proximal one-fourth of the fin between rays 2 and
13 or 14 is pigmented. The base of the caudal fin
never becomes outlined with melanophores, but
some melanophores develop on the dorsal second-
ary caudal rays.

Recently preserved pelagic juveniles of S. pin-
niger, 32 to 35 mm, are covered with orange
chromatophores which are lost during prolonged
preservation. They are present on the dorsal part
of the head, on the snout, around the orbit, and on
the opercle. On the body they are concentrated
along the myosepta and lateral midline, with
greater numbers on the dorsal half of the body but
also e.xtending to the ventral margin. Orange
chromatophores are also concentrated on the spi-
nous dorsal fin, along the basal one-fourth of the
caudal fin, and the anal fin membrane around the
anal spines.

A general increase in melanistie pigmentation
occurs in benthic juveniles >59 mm. On the head,
the two pigment bars beneath the orbit remain
distinct and extend over the operculum. Pigment
increases between the saddles obscuring the pat-
tern seen on pelagic juveniles. Melanophores are
added to both the inner and outer surfaces of the
pectoral fin base and on the basal one-third of the
pectoral fin blade. The pelvic fin remains unpig-
mented. The addition of melanophores to the spi-
nous dorsal fin obscures the pattern seen on

pelagic juveniles although the black blotch re-
mains intense and distinct. The entire caudal fin is
lightly pigmented with more intense pigment oc-
curring over the bases of the primary rays and all
upper secondary rays.

Occurrence (Figures 10, 11). — Adults of S. ptn-
ntger occur between Cape Colnett, Baja Califor-
nia, and southeast Alaska (lat. 56" N, long. 134°
W) (Hart 1973). Off Oregon they are most common
on the continental shelf between 100 and 200 m
(Snytko and Fadeev 1974). A major population
concentration has been found between lat. 44°30'
and 45" N off Oregon (Snytko and Fadeev 1974).

:Li.-^_

iui

£

<^ 10

MAR

-H 1 H/—< 1

APR

-I 1 w^^ 1

MAY

JUN

'< II f

AUG

40 60 60 100

Standord Length (mm)

120 180 190

Figure ll. — Seasonal occurrence of larvae and juveniles of
Sebastes pinniger off Oregon. Data from 1964 to 1975 combined.
Dashed line separates pelagic and benthic stages.

■^

.'

:

4 1 ^
•• •

/."

- Larvae

Pelagic Juveniles

TIj"

T r

f Benthic Juve

uveniles

Figure lO. — Number of specimens and location of capture of larvae and juveniles of Sefeasfespjnm^er off Oregon 1 1964-75 1 described in

this paper-

29

FISHERY BULLETIN; VOL, 77, NO 1

Larvae, including transforming specimens, of .S.
pinnigcr in our collections were captured at a wide
range of stations from 13 to 306 km offshore. The
largest numbers and smallest larvae (<8.8 mm)
were taken at stations 83 to 120 km off Newport
beyond the continental shelf break. This may
partly be a reflection of increased sampling effort
in that area. Pelagic juveniles occurred at a simi-
lar wide range of stations, mostly beyond the con-
tinental shelf Interestingly, 30 specimens, rang-
ing in length from 8.9 to 18.6 mm were captured
306 km off Coos Bay, Oreg., well beyond the conti-
nental shelf Perhaps this wide ranging offshore
occurrence of larvae and pelagic juveniles is re-
lated to their morphology. The larvae are quite
stubby and deep bodied with particularly long
head spines, features which could contribute to
increased flotation and dispersal by currents. Most
specimens were captured in oblique midwater
trawl and bongo net tows. Three benthic juveniles
were taken close to the coast in depths of 30 to 35
m.

Reported spawning times for S. pinniger are
November to March off California (Phillips 1964i
and January to March off Oregon, Washington,
and British Columbia (Westrheim 1975). Larvae
<10 mm were taken March through June, and
larger pelagic specimens were taken March
through August. The wide range in lengths, 9 to 25
mm in March, 7 to 38 mm in April, 8 to 34 mm in
May, 9 to 43 mm in June, may be indicative of
protracted and variable spawning. Benthic
juveniles were taken in June and August.

Sehastes pinniger is one of the most abundant
trawl-caught rockfish species on the continental
shelf off Oregon together with S. flavidus and S.
entomelas (Snytko and Fadeev 1974). In trawl
surveys off Oregon it ranked either first or second
only to S. entomelas in biomass over the shelf
(Demory et al. 1976). It was one of the major con-
tributors to "other rockfish" landings in Oregon
during 1963-71 (Niska 1976). Larvae and
juveniles were the most numerous in available
collections of the three species described in this
paper.

SEBASTES HELVOMACULATUS AYRES

(Figures 12, 13)

Literature. — Westrheim etal. (see footnote 9) pre-
sented a schematic illustration of a preextrusion
larva of S. helvomaeulatus and described the

pigment pattern in a tabular form. The latter table
was also in Westrheim (1975). Preextrusion lar-
vae (mean total length =4.1 mm) have a ventral
midline row of usually <16 (83"^* of 120 larvae)
melanophores which stop short of the anus usually
by as much as four myomeres. Pigment is absent
from the dorsal midline, the head, nape, and lower
jaw, and is usually not in the hypural region. The
illustration shows some melanophores over the
hindgut and ventrally beneath the yolk sac. Wes-
trheim (1975) added that larvae of S. hel-
vomaeulatus, along with 10 other species which
had been reared for several days, develop pigment
spots on the head, nape, and/or lower jaw.

Identification (Table 10, Appendix Tables 2-6). —
Twenty-six specimens of S. helvomaeulatus, 7.7 to
183 mm long, were identified. Juveniles were
identified using the following combination of
characters obtained from specimens examined in
this study;

Gill rakers = 28-31

Lateral line pores = 35-43

Pectoral fin rays = 15-17, usually 16

Anal fin soft rays = 5-6, usually 6

Dorsal fin soft rays = 12-14, usually 13

Supraocular spine = present

Interorbital space = concave.

Of the Sebastes species occurring off Oregon, S.
helvomaeulatus has the best fit to the above
characters. Sebastes aurora and S. elongatus also
agi'ee with many of these characters, butS. aurora
was eliminated since it has 24 to 28 gill rakers and
S. elongatus was eliminated since it does not have
a supraocular spine. Larval and juvenile speci-
mens of S. elongatus identified from our collec-
tions are noticeably more slender than specimens
of S. helvomaeulatus and also are pigmented dif-
ferently. Pigment pattern, body shape, time of oc-
currence, and constancy in number of anal fin soft
rays and pectoral fin rays helped link together the
developmental series.

Distinguishing Features. — Characters useful in
distinguishing the smallest larva of S. hel-
vomaeulatus identified, 7.7 mm, are the pig-
mented fringes of the pectoral and pelvic fins; the
general lack of body pigment; melanophores in-
side the tip of the lower jaw; narrow interorbital
distance (317f HL); long, deeply serrated, parietal
spines (27% HL); and relatively long pectoral fins

30

RICHARDSON and LAROCHE; DEVELOPMENT AND OCCURRENCE OF ROCKFISHES

8.0 mm

10.9 mm

13.4 mm

FIGURE 12. — Planktonic larvae (8.0, 10,9 mml and transforming specimen (13.4 mm) o( Sebasles helvomaculatus.

31

FISHERY BULLETIN: VOL. 77, NO, 1

<. ^^,,, <

18 4 mm

^/y^A

41 6 mm

■^

Figure 13. — Transforming specimen (18.4 mm) and pelagic juveniles (22.4, 41.6 mm) of Sehastes helvomaculatus .

{2A'7c SL). Later stage larvae change very little in larva to pelagic juvenile. Meristics, presence of a

appearance from the smallest larva, except for an supraocular spine, the concave shape and narrow

increase of dorsolateral internal gut pigment. A width of the interorbital space, the patch of

distinctive pigment patch appears on the caudal melanophores on the caudal peduncle, and the

peduncleduring the period of transformation from single melanistic pigment saddle extending pos-

32

RICHARDSON and LAROCHE: DEVELOPMENT AND OCCURRENCE OF ROCKFISHES

Table 10.— Meristics from larvae and juveniles of Sebastes helvomaculatus off Oregon, based on unstained specimens Specimens
above dashed line are undergoing notochord flexion. All specimens had 8 superior and 7 inferior principal caudal fin rays and 7
branch iostegal rays on each side.

Standard
length
(mm)

77
80
80

Dorsal Anal fin

fin spines spines

and rays and rays

Pectoral
fin rays

Right

Pelvic fin
spines and rays

Left Right

Gill rakers
(first arch)

Lateral
line pores

Right

IIR7
III2.7

16
16

16

16
16

l.(')
l.(')
I.C)

l.(')
I.C)
I.C)

Right

Diagonal
scale
rows

88

—

111^.6

16

99

Xll|2,13

III2.6

16

109

XIIIM3

IIP.6

16

= 120

XIII'.IS

111^6

16

= 120

Xll|2,13

111^.6

16

=134

Xlll',13

lll=,7

16

=134

Xll|2,13

MR 6

16

= 136

XIIP.13

W3

16

= 178

XIII2.12

111^6

16

= 179

Xlll'.12

lll',6

16

= 184

XIIIM3

111^6

16

=184

Xlll',12

111^6

16

= 186

XIIIM3

III.6

16

'198

Xlll,13

III.6

16

'20 3

Xlll,14

111,6

16

■'21 6

XIII, 13

111,6

16

«22 1

XIII.14

111,6

16

422 2

XIII.13

111,6

16

422 4

Xlll,13

111,6

16

"238

Xlll,12

111,5

16

•41 6

Xlll,13

111,6

16

M364

XIII.13

111,6

16

5183

XIII.14

111,6

17

16
16

16
16
16
16
16
16
16
16
16
16
17
16
16
16
16
16
15
16
16
15
16

1.5
1.5
1.5
1.5
1.5
1,5
1,5
1.5
1.5
1.5
1,5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5

1.5

—

—

_

_

1.5

—

—

_

_

1.5

—

_

_

1.5

—

_

—

_

1,5

—

_

—

1,5

—

_

1.5

—

_

—

_

1.5

—

21+9 = 30

_

1.5

21+9=30

22 + 9 = 31

•42

—

1.5

21+9 = 30

21+9 = 30

_

_

1.5

21+9 = 30

20+8=28

_

_

1.5

21+9 = 30

21+9 = 30

42

_

1.5

19+8-27

19+8=27

—

—

1.5

21 +8 = 29

21+8 = 29

.40

_

1.5

21+9 = 30

20 + 8 = 28

-39

_

1.5

21+8=29

21+8=29

-39

_

1.5

20 + 9=29

20+8 = 28

-40

• 40

1 5

20+8=28

20+8=28

-38

-38

1.5

21+9=30

21+9 = 30

=41

-41

1.5

20 + 9 = 29

20 + 9 = 29

-43

-43

1.5

22 + 9=31

22 + 8=30

39

38

1.3

21+9 = 30

21+9=30

35

35

1,5

22 + 9 = 31

22+9=31

40

39

'Not formed

•'Posterior dorsal or anal spine appears as a soft ray

=Transtormtng

•Pelagic juvenile

^Benihic juvenile

teriorly from the nape to dorsal spine XI and ven-
trally about one-half the distance to the lateral
line, all serve to distinguish pelagic juveniles.

General Development. — The smallest larva of S.
helvomaculatus identified, 7.7 mm, is in the final
stage of notochord flexion, which is completed by
8.8 mm. Transformation to pelagic juvenile begins
in larvae =12 mm long with the initiation of spine
formation in the dorsal and anal fin "prespines"
and the appearance of a lateral pigment patch on
the caudal peduncle. Transformation of the "pre-
spines" to spines is completed in specimens >19
mm at which time some pigment appears beneath
the spinous dorsal fin and pigment is added to the
dorsal margin of the caudal peduncle pigment
patch marking the beginning of pelagic juveniles
pigmentation. More pigment is added beneath the
first dorsal fin during the pelagic juvenile period
although the saddle never becomes pronounced.
Additional small external melanophores cover
most of the fish by the end of the pelagic juvenile
period, which probably lasts until =40-60 mm.
The largest pelagic juvenile examined was 41.6
mm and the smallest benthic juvenile was 1.36.4
mm.

Morphology (Tables 4, 11). — Twenty-six speci-
mens of S. helvomaculatus, 7.7 to 183 mm long,
were measured for developmental morphology.
Relative body depth/SL changes little at the pec-
toral fin base, decreasing slightly then increasing
while it generally increases at the anus. Snout to
anus distance increases from 56 to 63 or 64% SL
and the snout to pelvic fin distance increases
somewhat then decreases.

Head length increases slightly (41-42*2 ) then
decreases (38%) with respect to standard length.
Eye diameter decreases (39-32% HL), as do the
interorbital distance (31-15% HL) and snout
length (32 or 33-27% HL). Upper jaw length in-
creases from 44-46 to 52% HL. The length of the
angle gill raker first increases (13-15% HL) then
decreases ( 1 1% ).

Larvae and juveniles <24 mm have a weak
symphyseal knob which becomes less obvious with
development.

Fin Development (Tables 4, 10, 11).— The adult
complement of 15 to 18 (usually 16) pectoral fin
rays can be counted on the smallest larva, 7.7 mm,
of S. helvomaculatus although the ventralmost
rays are not fully developed. Pectoral fins are

33

FISHERY BULLETIN: VOL 77. NO 1

Table 1 1. — Measurements (millimeters) of larvae and juveniles of Sehastes helvomaculatus from waters off Oregon Specimens

above dashed line are undergomg notochord flexion,

E m

?

U

i

n 2 *

I .S

^a

2y= -sBfi "£

).^>™2ca> (OCT

£ ti

(0 "* —

: 3! a?

7 7

95

43

32

1 1

1 5

1 2

1

25

1 6

1 9

96

64

10

30

10

10

- (')

(?)

I')

60

96

4 4

32

96

1 5

1 3

1

28

1 7

20

1

68

1 2

33

090

004

090 -

(')

(')

(')

80

9.9

46

34

1 1

1 4

1 3

1

26

I 6

1 7

1

66

10

33

78

08

78

(')

(')

(')

88

10,9

52

39

1 3

1 4

1 4

1 2

29

1 9

22

1 1

40

1 3

36

78

10

1 2

48

{")

80

(*)

99

12,3

58

4 1

1 3

16

1 5

1 3

33

26

24

1 1

1 2

1 6

40

80

22

1 3

56

88

12

60

109

134

65

4 4

1 5

1 8

1 6

1 4

37

28

26

1 2

1 6

1 7

45

70

22

—

62

82

1 3

76

«120

149

74

49

1 6

24

1 8

1 5

4 1

30

30

1 2

1 9

20

52

80

24

1 3

78

1 1

1 8

1 1

'120

144

7 1

49

1 5

26

1 9

1 5

4 3

3 1

34

1 3

2 1

24

52

72

24

—

88

—

1 9

1 2

'134

16 8

85

54

1 6

2 7

20

1 6

4 1

34

33

13

24

29

60

66

30

—

82

—

1 9

1 4

'134

168

85

56

18

26

20

1 6

4 7

36

36

1 5

24

26

57

72

26

1 3

72

—

1 9

1 3

'136

168

85

58

22

24

20

1 5

4 4

33

33

1 3

22

24

62

—

28

1 1

80

1 4

1 9

1 4

'17,8

22 1

107

75

2 7

32

24

1 8

57

4 5

45

1 6

34

38

72

1

32

—

1 1

23

26

23

'179

22 2

112

73

26

29

2 4

1 7

57

42

4 5

1 7

3 1

32

80

80

028

1 3

1 1

—

28

22

'18 4

229

11

6 7

2 1

30

2 5

1 9

59

43

49

1 8

32

37

70

096

36

1 4

1 1

2 1

—

1 9

'184

23

110

72

1 8

34

2 7

1 8

57

4 4

52

1 8

34

37

70

70

34

1 3

1 1

27

30

26

'186

21 1

120

80

2 7

34

26

19

58

43

48

1 8

34

34

88

72

24

1 3

1 1

—

26

—

'198

24 6

120

82

28

33

28

2 1

64

46

52

1 8

3 1

36

82

—

36

1 3

1 2

—

26

22

'20 3

25 3

128

84

28

40

28

20

62

4 7

53

1 8

^

4 1

90

80

34

1 3

1 2

—

30

20

'21 6

26 4

130

84

2 5

40

28

20

7 1

52

57

20

—

40

86

—

14

—

1 2

—

32

30

'22 1

26 4

142

89

30

4 2

30

1 9

72

53

59

20

34

44

98

0,72

26

—

1 4

28

32

27

'22 2

27 7

146

93

30

4 2

30

1 9

67

5 1

59

20

42

4 4

10 7

0,46

32

—

1 3

26

3 1

3 1

'22 4

27 7

134

8,4

26

38

3 1

20

72

56

60

20

4 1

48

88

—

44

1 1

1 3

30

32

32

'23 8

29 1

157

94

3 1

4 3

2 9

1 9

72

52

64

22

39

43

107

40

30

—

1 2

28

34

—

'41 6

49 8

26 2

165

4 4

70

57

22

11 8

88

70

34

56

72

166

18

—

042

2 1

49

6 1

64

'136 4

169

86

51 8

140

26 7

183

6 7

44

323

37 6

120

197

30

53 8

16

—

13

57

174

20 7

270

= 183

219

118 1

68 1

180

35 8

18 9

11 2

633

494

48 4

18,0

28 2

429

74,5

—

—

0,32

7,0

276

31,0

310

'Usually third or founh m
'Usually mtdfin
^The second spine
*Not formed
^Forming
'Transforming
'Pelagic juvenile
'Bentfiic juvenile

larvae.

fittfi or

sixth in

juveniles

rather long, averaging 24-269!^ SL during the
pelagic period. Depth of the pectoral fin decreases
from 12''f in flexion larvae to 97? in benthic
juveniles.

Pelvic fin spines and developing rays are visible
on the 7.7 mm larva. The adult complement of I, 5
is countable on the smallest postflexion larva, 8.8
mm. The relative length of the pelvic fin increases
from 14 to 23'7r^ SL with development. The pelvic
spine, always shorter than the pelvic fin rays, in-
creases from 8% SL in flexion larvae to IS'/r in
transforming larvae and then decreases to 15'% in
benthic juveniles.

The adult complement of 8 + 7 principal caudal
fin rays can be counted on the 7.7 mm preflexion
larva. Flexion is completed by 8.8 mm. Superior
and inferior secondary caudal rays on two stained
juveniles 22.4 and 23.8 mm long, were 12 + 12 and
11 + 11, respectively.

Bases of dorsal and anal fin spines and rays are
visible on the 7.7 mm larva. Rays and spines (in-
cluding "prespines"! are fully formed by 9.9 mm
and the adult complements can be counted. "Pre-

34

spines" become spines in specimens >19 mm. The
longest dorsal spine increases from 19% HL in
postflexion larvae to 377f in benthic juveniles. The
longest dorsal ray, always longer than the longest
dorsal spine, increases from 23 to 43*^7^ HL during
development. The longest anal spine increases
from 16 to 49^r HL.

Spination iTables 4, 12). — Spines on the left side
of the head of the smallest S. helvomaculatus (1.1
mm) include the parietal; first and third anterior
preopercular spines; second, third, and fourth
posterior preopercular spines; postocular; pterotic;
inferior posttemporal; and first spine of the
superior infraorbital series.

The parietal spine and ridge are deeply serrated
in larvae and pelagic juveniles, but the serrations
are no longer visible by 41.6 mm. The parietal
spine is very long in flexion larvae, averaging 27'^
HL. Its length decreases with development to 3%
HL in benthic juveniles. The much smaller nuchal
spine, which appears by 8 mm, averages 29f HL in
flexion larvae and increases to 4 or 5'S in postflex-

RICHARDSON and LAROCHE; DEVELOPMENT AND OCCURRENCE OF ROCKFISHES

Table 12.-

-Development of spines in the head region o(Sebastes helvomaculatus larvae and juveniles. Specimens above dashed
line are undergoing notochord flexion. + denotes spine present and - denotes spme absent.

Standard

length
(mm)

Panetal Nuchal

Preopercular
' (anlenof series)

Preopercular
(posterior series)

Opercular
Superior Inferior

Inler-
oper-
cular

Sub-
oper-
cular

Pre-
ocular

Supra-
ocular

Post-

1st 2d 3d

1st

2d

3d

4lh

5th

ocular

7 7
80
8.0

+ —
+ +

+ — +
+ - +
+ — +

-

+

+

+
+

+

-

-

-

-

-

-

+

8.8
9.9
10.9
'12.0
'12.0
'13.4
'13.4
'13.6
'17.8
'17.9
'18.4
'18.4
'18.6
=19.8
'20.3
321.6
322.1
322.2
322.4
323.8
341.6

'136-4

'183

+ +

+ +

+ +

+ +

Table 12.— Continued.

Infraorbitals

Nasal

Coronal Tympanic Plerotic

Posttemporal
Superior Inferior

^'Cr^:.'

Superior

Supra-

(mm) 1st 2d

3d

1st 2d 3d

4th

cleithral Cleithral

77
80
80

-

+ - -
+ - -
+ - -

-

-

- - +

- - +

- - +

- +

- +

- +

-

9.9

10.9
'12.0
'12.0
'13.4
'13.4
'13.6
'17.8
'17.9
'18.4
'18.4
'18.6
319.8
320.3
321.6
322.1
322.2
322.4
323.8
341.6

'136.4

'183

I})
I})

-(')

(')

'Transforming

^Bump indicating beginning of spine formation

^Pelagic juvenile

'Benttiic juvenile

ion, transforming, and pelagic juvenile stages.
The nuchal and parietal spines are fused together
by the time juveniles are 42 mm long.

The posterior preopercular spine series is prom-
inent in S. helvomaculatus larvae. The third spine

of the series is weakly serrated in larvae >8 mm
up to pelagic juveniles. It is relatively long in
larvae averaging 27 to 31'7f HL in flexion and
postflexion stages. Its length decreases to 2'7f in
benthic juveniles when it is no longer serrated.

35

FISHERY BULLETIN VOL, 77. NO, 1

Very weak serrations appear on the second and
fourth posterior preopercular spines of most larger
larvae and smaller pelagic juveniles. All five pos-
terior preopercular spines are present on speci-
mens >8.0 mm. The first and third anterior
preopercular spines seen on the smallest larva are
no longer visible on specimens >23 mm. The sec-
ond anterior preopercular spine never develops.

The superior and inferior opercular spines are
present on all specimens >8 mm. The interopercu-
lar spine is present at 8.8 mm and persists into
benthic juveniles. The subopercular spine is pres-
ent just above the interopercular spine on the
largest benthic juvenile, 183 mm.

The supraocular ridge and the anterior margin
of the postocular spine are serrated on specimens
up to 23.8 mm. The preocular and supraocular
spines are first seen as bumps in a 13.4 mm speci-
men. Serrations are present on the supraocular
spine but disappear along with those on the su-
praocular ridge on larger pelagic juveniles.

The first superior infraorbital spine is visible up
to 23 mm. The second superior infraorbital spine
appears on specimens 12 to 23 mm. The fourth
superior infraorbital spine is present on larvae >8
mm and the third superior infraorbital spine is
present on larvae >13.4 mm. The third and fourth
spines both disappear by 23 mm. The first and
second spines of the inferior infraorbital series are
present on all specimens >8 mm but appear only
as blunt projections on benthic juveniles. The
third inferior infraorbital spine never develops.
The nasal spine appears as a bump by 9 mm and
becomes strong and sharp during the larval
period.

The tympanic spine develops by 41.6 mm and
appears as a strong sharp spine on benthic
juveniles. The pterotic spine is present on all
specimens >41.6 mm. The inferior posttemporal
spine is present on all specimens examined but is
minute on the two benthic juveniles, 136 and 183
mm, and probably disappears in larger specimens.
The supracleithral spine is present on all speci-
mens >8.0 mm. The superior posttemporal ap-
pears at 13.4 mm and is present on all larger
specimens. Posterior to the opercle the cleithral
spine appears on all specimens >19 mm.

Scale Formation. — Lateral line pores first appear
anteriorly and are visible on specimens >17 mm.
Scale formation begins on pelagic juveniles >23
mm.

Pigmentation. — The smallest larva of S. hel-
vomaculatus, 7.7 mm (similar to the 8.0 mm
specimen illustrated), has pigment on the head
over the brain. Melanophores line the inner tip of
the lower jaw. In the abdominal region, an inter-
nal melanistic shield is present over the dorsolat-
eral surface of the gut. No other pigment is visible
on the body. The pectoral and pelvic fins are
fringed with expanded and fused melanophores
and have a light scattering of more contracted,
elongate melanophores on the fin blades. Both
inner and outer pectoral fin base surfaces are un-
pigmented.

During larval development, pigment over the
brain becomes obscured. At 13.4 mm pigment in-
side the lower jaw disappears. Specimens >17 mm
develop two to six internal melanophores dorsally
on the opercle.

During the transformation period, 12.0 to 18.6
mm, two or three melanophores may appear just
posterior to the orbit on specimens >18 mm. In-
ternal gut pigment increases ventrolaterally
reaching the ventral surface of the gut by 17.9
mm. The anterior margin of the cleithrum is usu-
ally unpigmented. A patch of 9 to 10 large stellate
melanophores appears laterally on the caudal
peduncle at 12.0 mm at the beginning of the trans-
formation period. Melanophores are added to this
patch until it extends to the dorsal body surface at
= 18 mm. Melanophores in this patch often appear
expanded and fused. The pectoral and pelvic fins
remain fringed with pigment although this may
not be obvious if the fins are frayed. The number of
melanophores on the fin blades generally de-
creases.

During the pelagic juvenile period, 19.8 to 41.6
mm. pigment appears over the head surface,
snout, and upper lip of specimens "^22 mm.
Melanophores are added along the posteroventral
margin of the orbit and a patch of melanophores
appears just dorsal to the first superior infraor-
bital spine. The internal pigment patch on the
operculum remains distinguishable. Internal gut
pigment becomes increasingly obscured by muscu-
lature. A single saddle of melanophores develops
on the dorsal surface of the body over the nape and
beneath the spinous dorsal fin anterior to dorsal
spine XI. The first melanophores generally appear
there at the onset of the pelagic juvenile stage,
although a few may develop earlier. This saddle
extends ventrolaterally from the nape to the vicin-
ity of the supracleithral spine and from the spi-
nous dorsal fin halfway to the lateral line by 22

36

RICHARDSON and LAROCHE: DEVELOPMENT AND OCCURRENCE OF ROCKFISHES

mm. By 41.6 mm small external melanophores
cover all but the ventralmost one-fourth of the
abdominal region including most of the pectoral
fin base and the dorsal one-fourth of the gut re-
gion. The dorsal saddle and internal gut pigmen-
tation still appear as more darkly pigmented
areas. The caudal peduncle patch expands to the
dorsal and ventral body margins. Specimens >20
mm have a few melanophores extending an-
teriorly from the peduncle patch along the dorsal
body margin under the posteriormost dorsal rays.
By 41.6 mm the entire tail region of the body is
also covered with small external melanophores,
although the caudal peduncle patch and dorsal
midline melanophores remain visible. Pectoral
and pelvic fins lose all pigment by 41.6 mm, except
for a patch of small melanophores on the base of
the central pectoral rays. The spinous dorsal fin
becomes completely covered with small melano-
phores by 41.6 mm and small melanophores cover
the proximal one-fourth of the soft dorsal fin.
Small melanophores extend onto the bases of the
caudal fin rays by 41.6 mm.

Melanistic pigment is inconspicuous on the
benthic juveniles examined. 136 and 183 mm. The
caudal peduncle pigment patch is no longer visi-
ble.

Occurrence (Figures 14, 15). — Sebastes hel-
vomaculatus ranges from Coronado Bank, off San
Diego, Calif, to Albatross Bank, Gulf of Alaska,
and occurs in depths from 133 to 456 m (Chen
1971). It is apparently primarily a deepwater
species judging by some of the older common
names given to it, "deep-water scacciatale" and

"deep-water scratch-tail" (Phillips 1957). The
largest numbers and smallest larvae were taken
83 and 120 km off Newport beyond the continental
shelf break. Most pelagic juveniles were taken at
the same locations as the larvae, probably reflect-
ing the increased sampling effort in that area. One
benthic juvenile, 136 mm, was taken in an otter
trawl at a depth of 370 m (lat. 44°47.9' N, long.
124°40.9' W). A second juvenile, 183 mm, was col-
lected after a seismic profiling explosion on
Stonewall Bank ( =lat. 44°30' N, long. 124°25' W).

JUL

I 1 1 ihX-

AU6

J.

X-L

SEP

OCT

NOV

JlL

-4-

20

to 60 80 100 120 140 180 190

Standard Length (mm)

Figure 15. — Seasonal occurrence of larvae and juveniles of
Sebastes helvomaculatus off Oregon, Data from 1961 to 1976
combined. Dashed line separates pelagic and benthic stages.

' ' ' 1^^-

, w--^-^-

'• )"-" -

■^ -

'. '. i .' L^.
\ 1

-

i

Jl'

A „,

Pelagic

Juveniles ]•

, , "^r-.

FIGURE 14. — Number of specimens and location of capture of larvae and juveniles of Se6as^es helvomaculatus off Oregon (1961-76)

described in this paper.

37

FISHERY BULLETIN: VOL, 77, NO, 1

Based on examination of gonads, Westrheim
(1975) reported that parturition of S. hel-
vomaculatus takes place primarily in June from
Oregon to British Columbia. We took small larvae
>10 mm only in July and August. Pelagic
juveniles were captured in August, September,
and November. The two benthic juveniles were
taken in July.

Adults of S. helvomaculatux are uncommon in
Oregon trawl landings iNiska 1976). They ranked
9th and 16th in biomass in trawl surveys on the
Oregon continental shelf and 8th on the continen-
tal slope together with S. elongatus and S. zacen-
triis (Demory et al. 1976). Larvae and juveniles
were not common in our collections.

COMPARISONS (TABLE 13)

Prior to this paper, developmental series of 7 of
the 69 northeast Pacific (including the Gulf of Cal-

ifornia) species of Sehastes had been described: S.
cortezi, S. sp. Gulf Type A, S. jordani, S. levis, S.
macdonaldi , S. melanostomus , and S. paucispinis
(Moser 1967, 1972; Moser et al. 1977; Moser and
Ahlstrom 1978). While pelagic stages of these
species exhibit some similarities to the three de-
scribed by us, they also differ in a number of
characters. The most notable of these are discus-
sed here in a comparative sense.

Flexion and postlarvae of S. pinniger are quite
deep bodied (38-40/f SL) although body depth at
the pectoral fin base decreases considerably (33'7f
SL) by the pelagic juvenile stage. Larvae and
juveniles of S. melanostomus are also deep bodied.
Pelagic stages of S. Jordani are comparatively
slender (17-24'7< SL). Prior to completion of
notochord flexion, S. paucispinis is also relatively
slender bodied. Pelagic stages of S. crameri, S.
he/vomaculatus. S. levis. and S. macdonaldi are
somewhat intermediate in body depth. Snout to

TABLE13, — Morphometric comparison of larvae and juveniles of nine species ofSebastes from the northeast Pacific. Values are mean
percentages of body proportions related to standard length (SL) or head length <HLl, Numbers m italics represent values for two
developmental stages combined.

S cor-t-

S, Cra-

S Gull

S he/vo-

S yor-

S.

S, mac-

S. me/a-

S, paucr-

S pin-

Item

ezi'

mer/

Type A'

maculatus

dam'

levts'

donaldi'

nosfomus'

spinis'

niger

Body depth at pectoral fin baseiSL

Preflexion

_

—

_

—

17

—

23

—

20

_

Flexion

32

33

21

28

32

36

23

40

Postllexion

32

33

38

Transforming

32

33

24

34

34

39

30

36

Pelagic )uvenile

_

33

—

31

22

35

31

37

27

33

Benthic luvenile

—

34

—

33

—

—

—

—

—

35

Snout to anus lengthSL

Preflexion

—

_

—

—

36

—

42

—

41

—

Flexion

_

54

_

56

42

49

52

57

45

59

Postllexion
Transforming

—

60
61

—

59
62

5/

59

60

59

57

60
61

Pelagic luvenile

—

62

—

63

53

63

64

64

62

61

Benthic luvenile

_

65

_

64

_

_

_

_

_

64

Pectoral fin length'SL:

Preflexion

7-9

—

6-9

—

7

9

8

—

—

_

Flexion

9-12

17

—

24

8

35

13

20

27

25

Postflexion

21

20

24

1 1

25

Transforming

21

27

26

20

45

19

22

36

27

Pelagic luvemle

23

32

—

27

22

41

30

26

28

26

Benthic juvenile

—

30

—

27

_

—

_

—

_

24

Pelvic fin lengtti>SL:

Preflexion

—

—

—

—

—

—

4

—

—

—

Flexion

7

_

14

1

6

6

12

14

14

Postflexion

15

16

17

Transforming

_

21

_

19

9

21

14

16

35

23

Pelagic juvenile

—

21

_

19

14

24

22

20

25

22

Benthic juvenile

_

21

_

23

-_

_

_

—

_

21

Parietal spine length HL:

Preflexion

—

—

Flexion

6

27

24

Postflexon

2r-22

7

25-34

18

20-23

20

Transforming

6

13

10

Pelagic juvenile

—

3

—

6

_

_

_

—

_

7

Benthic juvenile

3

Preopercular spine lengtti HL:

Preflexion

—

—

—

—

—

—

—

—

—

—

Flexion

18

27

34

Postllexion

17

_

31

_

_

35

_

32

Transforming

_

18

—

20

—

_

—

—

—

24

Pelagic juvenile

_

12

_

12

—

_

_

—

_

13

Benthic juvenile

-

7

-

2

—

—

—

—

—

5

'Values from Ivloser et al, (1977) and Moser and Ahlstrom (1978)

38

RICHARDSON and LAROCHE DEVELOPMENT AND OCCURRENCE OF ROCKFISHES

anus distance is markedly shorter in larvae and
juveniles oCS.jordaiii (36-53'^< SL) compared with
the other species.

The pectoral fins in S.jordani remain compara-
tively short (7-22% SL) during pelagic develop-
ment while those of S. levis attain an exceptional
size (to 45'7( SL). Late larval stages of S. pauci-
spinis also have outstandingly long pectoral fins
(36'"f SL). Fin lengths among the other species are
intermediate by comparison and vary to a lesser
degree during development. The pelvic fins of S.
pauc7spi>!ii' also become extraordinarily long (35'>
SL) during the late larval period whereas those of
S.jordani remain relatively short.

Parietal spine length varies among species with
the largest spines appearing in early larvae of S.
helvornacu/atus {279i HL) and S. sp. Gulf Type A
(25-349f HL). This spine is noticeablely short on S.
cramen (3-7% HL) during the entire pelagic
phase. The third preopercular spine is outstand-
ingly long on early larvae of S. macdonaldi (35%
HL) and S. pinniger (34% HL) but is compara-
tively short on S. cramen (17% HL) as is the
parietal.

Pigmentation on the paired fins varies from the
unpigmented condition in S.jordani to the heavily
pigmented fins of S. macdonaldi and S. crameri.
The pectoral fins of S. cortezi are pigmented at the
fin base but not the outer margin, while pigment is
primarily concentrated on the outer margin of the
fins in S. paucispinis, S. levis, and S. helvomacu-
latu.s at least during the early pelagic period. Pec-
toral fins of S. pinniger, S. melanostomus, and S.
sp. Gulf Type A are lightly pigmented.

General body pigmentation differs among the
species considered. Larvae of S. pinniger have a
'•haracteristic lack of body pigment. A patch of
uape pigment develops early in S. crameri and S.
macdonaldi. appearing more pronounced in the
former species. Postflexion larvae of both S. cram-
eri and S. macdonaldi develop pigment on the
entire spinous dorsal fin. A characteristic black
blotch develops on the posterior portion of the first
dorsal fin in pelagic juveniles of S. pinniger. Lar-
vae of S. melanostomu.'i, S. paucispini.'i, and S.
macdonaldi have a characteristically low number
of ventral midline melanophores, 4 to 11 (mean 8),
6 to 14 (mean 9), and 6 to 14 (mean 8), respectively.
A patch ofpigment forms on the caudal peduncle of
S. helvomaculatus , S . paucispinis, S.jordani, and
S. cortezi. The form of the patch varies with the
species and is most pronounced in S. hel-
vomaculatus. One characteristic melanophore ap-

pears at the base of the caudal fin in S. cortezi,
while melanophores form a line ofpigment at the
base of the caudal fin in S.jordani, but not in any
of the other species.

Pelagic juveniles of S. helvomaculatus develop
only one melanistic pigment saddle beneath the
spinous dorsal fin. Five distinct saddles form on S.
macdonaldi, S. crameri, S. levis, S. paucispinis,
and S. pinniger in comparable locations on the
body although a more blotchy pattern develops on
S. pinniger. On S. melanostomus, three pro-
nounced melanistic bars develop on the body. Ap-
parently no obvious saddles or bars develop on
pelagic juveniles of S. jordani or S. cortezi.

These comparisons together with distinguish-
ing features of each species given by us, Moser
(1972), Moser et al. (1977), and Moser and
Ahlstrom (1978), and range of occurrence should
aid in identification of all but the smallest larvae.
As additional species are described, such compari-
sons may also provide insight into relationships
within the genus Sebastes.

ACKNOWLEDGMENTS

We thank H. Geoffrey Moser for helpful advice
and for the use of unpublished data on color pat-
tern in a livejuvenile of S. crameri. Stuart G. Poss
offered useful advice on head spine terminology.
During the course of this study the following
people provided helpful information on Sebastes
spp.: Carl Bond, Jerry Butler, William N. Esch-
meyer, Colin Harris, Michael Hosie, Andy Lamb,
Bruce M. Leaman, Alex E. Peden. Jay C. Quast,
David Stein, Arthur D. Welander, Sigurd J. Wes-
trheim, Norman J. Wilimovsky. Range Bayer,
Robert A. Behrstock, Carl Bond, Jerry Butler,
Colin Harris, Michael Hosie, Robert Lea, Law-
rence Moulton. and Alex Peden provided addi-
tional specimens of Sebastes to examine. Special
thanks are extended to William G. Pearcy for al-
lowing us to use his extensive midwater trawl
collections from waters off Oregon. Lo-Chai Chen,
H. Geoffrey Moser, Stuart G. Poss, and Sigurd J.
Westrheim reviewed an earlier draft of the man-
uscript. This research was supported by a 1-yr ( 16
June 1976-15 June 1977) contract No. 03-6-208-
35343.

LITERATURE CITED

AHLSTROM. E. H.

1961. Distribution and relative abundance of rockfish

39

FISHERY BULLETIN; VOL 77. NO 1

{Sebastodes spp.) larvae off California and Baja Califor-
nia. Rapp. P-V. Reun, Cons. Int. Explor. Mer 150:169-
176.
1965, Kinds and abundance offi.'shes in the California Cur-
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Oceanic Fish, Invest, Rep. 10:31-52.

Bailey, R. M., J. E. Fitch, E. S. Her.ald. E. a. Lachner, C. C.

LINDSEV. C. R. ROBINS, AND W. B. SCOTf.

1970, A list of common and scientific names of fishes from
the United States and Canada, Am. Fish. Soc. Spec.
Publ. 6, 149 p

BARSLIKOV, V, V.

1973, A systematic analysis of the group Sebastex waki-
yai-S. paradoxus-S. steindachneri. Communication 2
(containing a redescription of .S. wakiyan. J Ichthyol,
(Engl, Transl, Vopr. Ikhtiol.l 13:824-833,

Chen, L.-C.

1971, Systematics, variation, distribution, and biology of
rockfishes of the subgenus Sfhastomus (Pisces, Scor-
paenidae,Sefca,s(e.<;). Bull, ScrippsInst,Oceanogr,,Univ,
Calif, 18, 115 p.

1975, The rockfishes. genus Sebaxtes (Scorpaenidae), of
the Gulf of California, including three new species, with a
discussion of their origin. Proc. Calif Acad. Sci. 40:109-
141.

DeLacy, A. C, C. R, Hit/., and R. L, Dryfoo.s,

1964. Maturation, gestation, and birth of rockfish iSebas-
todes) from Washington and adjacent waters. Wash.
Dep. Fish., Fish. Res. Pap. 2(31:51-67.

Demory, R. L., M. J. HosiE, N. Ten Eyck, and B. O,

FORSBERG.

1976. Marine resource surveys on the continental shelf off
Oregon, 1971-74. Oreg. Dep. Fish. Wildl,, Completion
Rep.. July 1, 1971 to June 30, 1975, 49 p.

EFREMENKO, V. N., AND L. A, LiSOVENKO.

1970, Morphological features of intraovarian and pelagic
larvae of some Sebastotles species inhabiting the Gulf of
Alaska. In P. A. Moiseev (editor), Soviet fisheries inves-
tigations in the northeast Pacific. Part V, p, 267-286,
(Transl, Isr, Program Sci, Transl,; available Clearing-
house Fed, Sci, Tech, Inf, Springfield, Va,, as TT71-
50127),

EIGENMANN, C, H,

1892, The fishes of San Diego. California, Proc, U.S.
Natl, Mus, 15:123-178.

FOLLETT, W. I., AND D. G. AINLEV.

1976. Fishes collected by pigeon guillemots, Cepphus co-
luniba (Pallas), nesting on Southeast Farallon Island,
California. Calif Fish Game 62:28-31,

Hart, J, L,

1973. Pacific fishes of Canada. Fish, Res. Board Can.
Bull, 180, 740 p.

Lea, R, N,, and J. E. Fitch.

1972, Sebastes rufinanus, a new scorpaenid fish from
Califomian waters, Copeia 1972:423-427,

Matsubara, K,

1943. Studies on the scorpaenoid fishes of Japan, Anat-
omy, phylogeny and taxonomy 1 and II, Trans, Sigen-
kagaku Kenkvusyo, Tokyo, 486 p,
MERKEL, T. J.

1957. Food habits of the king salmon, Oncorhynchus
tshawytscha i Walbaum), in the vicinity of San Francisco,
California, Calif Fish Game 43:249-270,

Miller, d. j,, .\nd r, n, lea.

1972. Guide to the coastal marine fishes of California.

40

Calif Dep, Fish Game, Fish Bull 157, 235 p,

Morris, R, W,

1956. Early larvae of four species of rockfish, Sebastodes.
Calif Fish Game 42:149-153,
MO.SER, H, G,

1967, Reproduction and development of Sebastodes
paucispinis and comparison with other rockfishes off
southern California. Copeia 1967:773-797,
1972, Development and geographic distribution of the
rockfish, Sebastes macdonaldi (Eigenmann and Beeson,
1893), family Scorpaenidae, off southern California and
Baja California. Fish, Bull,, US, 70:941-958.
M(.)SER, H. G., E, H, AHLSTROM, AND E. M, SANDKNOI',

1977, Guide to the identification of scorpionfish larvae
(family Scorpaenidae) in the eastern Pacific with com-
parative notes on species ofSebafttes and Helicolenus from
other oceans. U.S. Dep, Commer., NOAA Tech, Rep,
NMFS Circ, 402, 71 p,

MOSER, H. G., AND E. H. AHUSTROM.

1978. Larvae and pelagic juveniles of blackgill rockfish,
Sebastes melanostomus, taken in midwater trawls off
southern California and Baja California. J. Fish. Res.
Board Can, 35:981-996,

NISKA, E, L,

1976, Species composition of rockfish in catches by Oregon
trawlers 1963-71. Oreg. Dep Fish, Wildl, Inf Rep, 76-7,
80 p.

PACIFIC Marine Fisheries Commission.

1964-1976. Data series: Bottom or trawl fish section. Pac.
Mar. Fish. Comm., Portland, Oreg., p, 1-472, 500-510,

Phillips, J. B.

1957 A review of the rockfishes of California (family Scor-
paenidae), Calif Dep, Fish Game, Fish Bull 104, 158 p,
1964, Life history studies on ten species of rockfish (genus
Sebastodes). Calif. Dep. Fish Game, Fish Bull. 126, 70p

Powell, D, E., D, L. Alverson, and R, Livincstone, Jr.
1952, North Pacific albacore tuna exploration —
1950, U.S. Fish Wildl, Serv,, Fish, Leafl, 402, 56 p. i]

PRITCHARD, A. L., AND A. L, TESTER,

1944. Food of spring and coho salmon in British Colum-
bia. Fish. Res. Board Can Bull 65. 23 p.

QUAST, J. C, AND E. L, Hall,

1972. List of fishes of Alaska and adjacent waters with a
guide to some of their literature. U.S. Dep. Commer.,
NOAA Tech. Rep, NMFS SSRF-658, 47 p.

Richardson. S. L.

1977, Larval fishes in ocean waters off Yaquina Bay. Ore-
gon: abundance, distribution and seasonality January
1971 to August 1972. Oreg, State Univ, Sea Grant Coll,
Prog, Publ, ORESU-T-77-003, 73 p.

Richardson, S. L.. and W, G, Pearcy,

1977. Coastal and oceanic fish larvae in an area of up-
welling off Yaquina Bay. Oregon, Fish, Bull., US
75:125-145,

Rosenblatt, R. H., and L.-C. Chen.

1972. The identity o{ Sebastes babcocki and Sebastes rub-
rivmclus. Calif Fish Game 58:32-36,
SILLIMAN, R, P,

1941. Fluctuations in the diet of the chinook and silver
salmons iOncorhynchus tsckawytscha and O. kisutch ) off
Washington, as related to the troll catch of salm-
on. Copeia 1941:80-87.
SNVTKO, V, A,, AND N, S, FADEEV,

1974. Data on distribution of some species of sea perches
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RICHARDSON and LAROCHE DEVELOPMENT AND OCCURRENCE OF ROCKFISHES

mer - autumn season. Doc. Subm. Canada-USSR Meet,
on Fish, in Moscow-Batumi, USSR, November 1974, 14 p.
iTransl. 3436, Can. Transl. Ser.l

Taylor, W. R.

1967. An enzyme method of clearing and staining small
vertebrates. E>roc. US. Natl. Mas. 122(3596), 17 p.

VerHOEVEN, L, a. (editori.

1976. 28th annual report of the Pacific Marine Fisheries

Commission for the year 1975. Pac. Mar. Fish. Comm.,

Portland, Oreg., 46 p.
Waldron, K. D.

1968. Early larvae of the canary rockfish.Setastorfespm-
niger. J. Fish. Res. Board Can. 25:801-803.

Wales, J. H.

1952. Life history of the blue rocklish, Sebastodes mys-
tinus. Calif. Fish Game 38:485-498,
Weitzman,S. H.

1962. The osteology of Brycon meeki. a generalized
characid fish, with an osteological definition of the fami-
ly. Stanford Ichthyol. Bull. 8(1), 77 p.

WESTRHEIM, S. J.

1966. Northern range extensions for three species of
rockhsh iSebastesflai'idus.S.pauctspinis andS.ptnniger)
in the North Pacific Ocean. J. Fish. Res. Board Can.
23:1469-1471.

1975. Reproduction, maturation, and identification of lar-
vae of some Sehastes iScorpaenidae) species in the north-
east Pacific Ocean. J, Fish Res. Board Can. 32:2399-
2411.
WESTRHEIM, S. J., AND H. TSUYUKI.

1967. Sebastodes reedi, a new scorpaenid fish in the north-
east Pacific Ocean. J. Fish. Res. Board Can. 24:1945-
1954

1972. Synonymy of Sebastes caenaematicus with Sebastes
borealis, and range extension record. J. Fish. Res. Board
Can. 29:606-607.
WHITNEY, J. P.

1893. Salmon in salt water Forest Stream 41:120-121.
YOUNG, P. H,

1969. The California partyboat fishery 1947-1967. Calif
Dep. Fish Game, Fish Bull. 145, 91 p.

41

FISHERY BULLETIN VOL 77. NO 1

APPENDIX Table l. — Ranges of eastern North Pacific species ofSehastes.' This Hst does not include one new species being described by
Lea and Fitch (Chen 1975). Asterisk indicates species in the subgenus Sehastomus.

o o

— 3 ^

Species

Southern range limit

O 5

Northern range limit

S aleutianus

S alutus

S atrovirens

S aunculatus

S aurora

S babcocki

S borealis

S brevispmis

S camatus
'S caunnus^

S chlorostictus

S chrysomelas

S ciliatus

'S constellatus

S cortezi

S cramen

S dalli

S diploproa

S elongaius

S emphaeus
'S ensifer

S eniomelas
'S eos
'S exsul

S fiavidus

S gilli

S goodei
"S helvomaculatus

S hopkinsi

S lordani
"S lentiginosus

S lews

S macdonaldi

S maliger

S melanops

S melanostomus

S mtniatus

S mystinus

S nebulosus

S nigrocinctus
'S notius

S ovaJis

S paucispinis

S pendunculans

S phillipsi

S pinniger

S polyspinis

S pronger

S rastrelliger

S reedi
"S rosaceus
"S rosenblaW

S rubernmus

rubnvtnctus
'■ rufinanus

rufus

saxicola

semicinctus

serranoides

sernceps

Simulator

sinensis

spinorbis
umbrosus
variegatus
varispinis

' wilsoni
zacentrus

Monterey. Calif

La Jolla, Caht

Pt San Pablo, Ba)a

Hipolilo Bay, Baja

San Drego, Calif

San Diego, Calif

Eureka, Calif

Santa Barbara I , Calif

San Rogue, Baja

San Benito I . Baja

Cedros I , Baja

Natividad I . Baia

Dixon Entrance, B C

Thetis Bank. Baja

Gult ot Calif

Santa Catalina 1 . Calif

Sebastian Viscaino Bay, Baja

San Martin I , Baja

Cedros I . Baja

Punta Gorda, Calif ^

Ranger Bank, Ba/a

Todos Santos Bay. Baja

Sebastian Viscamo Bay, Baja

Gult of Calif

San Diego, Calif

Ensenada, Baja

Magdalena Bay, Baja

Coronado Bank, Calif

Guadalupe I . 6a|a

Cape Coinetl, Baja

Los Coronados I . Baja

Ranger Bank. Baja

Gulf of Calif

Pi Sur, Calif

Paradise Cove, Baja

Cedros I , Baja

San Benilo I , Baja

Pt Santo Tomas. Baja

San Miguel I , Baja

Pt Buchon, Baja

Uncle Sam Bank. Baja

Cape Coinetl. Baja

Pt Blanco, Baia

Gulf of Calif

Newport. Calil

Cape Coinetl, Baja

S E Alaska

San Diego, Calif

Playa Mario Bay. Baja

Crecent City, Calif

Turtle Bay. Baja

Ranger Bank, Baja

Ensenada. Baja

Cape Colnett, Baja

San Clemenli I , Calif

Guadalupe I , Baja

Sebastian Viscamo Bay, Baja

Sebastian Viscamo Bay Baja

San Benito I , Baja

Cedros I , Baja

Guadalupe I . Baja

Gulf of Calif

Gulf of Calif

Pt San Juanico, Baja

Queen Charlotte Sd . B C

Gull of Calif

Cortez Bank, Calif

San Diego, Calif

Aleutians and Japan

Bering Sea and Japan

Timber Cove, Sonoma Co , Calif

S E Alaska

Amphndile Pt , Vancouver I , 8 C

Amchilka I , Alaska

S E Kamchatka

Bering Sea

Eureka, Calif

Gult of Alaska

Copalis Head. Wash

Eureka. Caht

Benng Sea

San Francisco. Calif

Gult of Calif

Bering Sea

San Francisco. Calif

Alaska Peninsula

Green I , Montague I , Gult of Alaska

Kenai Peninsula, Gult ot Alaska

San Francisco. Calif

Kodiak. Alaska

San Francisco. Calit [''Wash)

Gult of Calif

Kodiak. Alaska

Monterey. Calif

Cape Scott. Vancouver I . B C

Albatross Bank. Gulf of Alaska

Farallon 1 . Calif

Le Perouse Bank, Vancouver I . B C

Santa Catalina I , Calif

Usal. Mendicino Co . Calif

Pt Sur. Calif

Gult of Alaska

Amchitka I , Alaska

Wash ^Bering Sea)

Vancouver I , B C

BC (''Bering Sea)

S E Alaska

S E Alaska

Guadalupe I . Baja

San Francisco. Calif

Kodiak. Alaska

Gult ot Calif

Monterey Bay. Calif.

S E Alaska

Eastern Kamchatka

Bering Sea

Yaquina Bay. Oreg

Sitka, Alaska

San Francisco, Calif CPuget Sd , Wash )

Avila, Calif CSan Francisco. Calif )

Gulf ot Alaska

San Francisco. Calif

San Clementi I . Calif

Mad River. Calif

S E Alaska

PI Pinos. Monterey Co . Calif

Redding Rock, Del None Co . Calif

San Francisco. Calif

San Pedro, Calif CPt Conception. Calif )

Gulf of Calft

Gulf of Calif

Pt Conception, Calif

Unimak Pass, Aleutian I

Gult of Calif

S E Alaska

Sanak 1 , Aleutians

'Compiled from Bailey etal ( 1970), Chen (1971). Lea and Filch (1972), Miller and Lea (1972), Ouast and Hall (1972). Rosenblatt and Chen (1972), Barsukov (1973),
Hart (1973), and Chen (1975), and original data for S emphaeus No records from ttie Sea of Okhotsk

^Includes S vexiiiaris (Chen 1975. W N Eschmeyer. Senior Curator tor Research, California Academy of Sciences. Golden Gate Park. San Francisco. CA 941 18,
pers commun November 1976)

^Based on data obtained dunng this study

42

RICHARDSON and LAROCHE: DEVELOPMENT AND OCCURRENCE OF ROCKFISHES

Appendix Table 2. — Chart showing interorbital curvature and presence or absence of the supraocu-
lar spine for rockiishes [Sebastes spp.) occurring off Oregon.' x indicates usual condition; o indicates
occasional occurrence.

Inlerorbital

Interorbital

Flat-convex Concave

Flat-convex Concave

Supraocular spine Supraocular spine
Species Present Absent Present Absent

Supraocular spine Supraocular spine
Species Present Absent Present Absent

S- aleutianus

S. alutus

S. aunculatus

S. aurora

S. babcocki

S. borealis

S. brevispinis

S. caunnus

S. chlorosticlus

S cramen

S. diploproa

S. elongatus

S. emphaeus

S. entomelas

S. eos^

S. flavidus

S goodei

S. helvomaculatus

S. lordani
S maliger
S melanops
S melanostomus
S miniatus
S mystinus
S nebulosus
S nigrocinctus
S paucispinis
S pinniger
S pronger
S rastrelliger
S reedi
S rosaceus^
S ruberrimus
S saxicola
S wilsoni
S- zacenlrus

' Compiled from Phillips ( 1 957) , Westrheim and Tsuyuki ( 1 967.
and original data for S emphaeus
^Species may be rare off Oregon

1972). Chen (1971). Miller and Lea (1972). and Hart (1973).

APPENDIX Table 3. — Numbers of dorsal, anal, and pectoral fin soft rays for rockiishes iSebastes spp.)
occurring off Oregon.' x indicates usual numbers, o indicates occasional occurence.

Species

Dorsal fin rays

Anal fin rays

Pecloral fm rays

11 12 13 14 15 16 17 5

10 11 15 16 17 18 19 20 21 22

S aleutianus

S alulus

S aunculatus

S aurora

S babcocki

S borealis

S brevispinis

S caunnus

S chlorostictus

S cramen

S diploproa

S elongatus

S emphaeus

S entomelas

S eos^

S tiavidus

S goodei

S helvomaculatus

S lordani

S maliger

melanops

melanostomus

miniatus

mystinus

nebulosus

nigrocinctus

paucispinis

pinniger

pronger
S rastrelliger
S reedi
S rosaceus^
S ruberrimus
S saxicola
S wilsoni
S zacentrus

'Compiled from Phillips (1957). Westrheim (1966), Westrheim and Tsuyuki (1967. 1972). Chen (1971). Miller and Lea
(1972). and Hart (1973), and onginal data for S emphaeus
^Species may be rare off Oregon

43

FISHERY BULLETIN: VOL 77. NO 1

Appendix Table 4. — Total numbers of gill rakers on first gill arch for rockfishes(Se6as/esspp.) occurring off Oregon.*
Species 22 23 24 25 26 27 26 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47

S aleutianus x x x x x x

S alutus xxxxxxxxx

S auriculatus x x x x x x

S aurora x x x x x

S babcocki x x x x x

S borealis x x x x x

S brevispinis x x x x

S caurmus x x x x x x x

S. chlorostictus x x x x x x

S crameri x x x x x x

S diplopora X X X X X X

S elongatus x x x x x x

S emphaeus x x x x x x x

S entomelas x x x x

S eos' X X X X X X

S flavidus X X X X X X X

S goodei x x x x x x

S helvomaculatus x x x x x x

S jordani x x x x x x x

S. maliger x x x x x

S melanops x x x x x x x

S rnelariostomus xxxxxxxxx

S miniatus xxxxx xxxx

S mysf/nus x x x x x x

S nebulosus x x x x x x

S nigrocinctus xxxxx

S paucispmis xxxx

S. pinntger x x x x x x

S. proriger xxxx xxxx

S. rastrelliger xxxx

S reed/ x x x x x x x

S fosaceus^ x x x x x x

S rubemmus x x x x x x

S. saxicola xxxxx

S wilsoni XX xxxx

S zacenfrus x x x x x x x

' Compiled from Phillips ( 1957), Westrhetm and Tsuyuki( 1967. 1972), Chen (1971). Miller and Lea (1972). and Hart (1973), and original data for S
empftaeus

^Species may be rare off Oregon.

44

RICHARDSON and LAROCHE DEVELOPMENT AND OCCURRENCE OF ROCKFISHES

3

1

2

O
O

Q

1

Q.

3

O

5

3

5

3

ra

O

fD

£

tl

ro

nj

-Q

-Q

■Q

O

CO

07 W CO CO </> t/l C/1

1

5 O.S

c o

O TD QJ

0)

a> o

i o t ^

t o c c

fe O O 0)

cocoi/icocococococo</)'^tocotococococococo

CD Cb o
C/) CO CO c

5d
. o

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:= (U

O Q.

tJCO

45

FISHERY BULLETIN VOL, 77. NO 1

Appendix Table 6. — Number of diagonal scale rows below the lateral line for rockfishes (Se6as(es spp.) occurring off Oregon.'
Species 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 56 59 60 61 62 63

S ateutinaus xxxxxxxxx

S alutus X X X X X X X

S aunculatus xxxxxxxx

S aurora xxxxxxxxxx

S babcocki

S borealis xxxxxxxxxxx

S. brevispinis x x x x x x

S caurinus xxxxxxxxxxxx

S chlorostictus x x x x x x

S crameri xxxxxxxxxxxxxxx

S diploproa x x x x x

S elongatus xxxxxxxxx xxxxx

S emphaeus xxxxxxxxxx

S entomelas x x x x x x

S eos^ xxxxxxxx

S flavidus X X X X x X

S goodei x x x x

S helvomaculatus x x x x x x x

S lordani

S matiger x x x x x x x

S melanops x x x x x x

S melanostomus x x x x x x

S minialus x x x x

S mystinus x x x x x x x

S nebulosus x x x x x x

S nigrocinctus xxxxxxxxxx

S paucispinis

S pinniger xxxxxxxx

S pTonger x x x x x x

S rastrelltger x x x x x x

S- reed/ x x x

S rosaceus^ xxxxxxxx

S rubemmus x x x x x x

S saxicola xxxxxxxxxxx

S wilsoni X X X X x X

S zacentrus xxxxxxxx

'Complied from Phillips (1957). Weslrheim and Tsuyuki (1967, 1972), Chen (1971), Miller and Lea (1972). and Hart (1973), and onginal data for S
emphaeus
^Species may be rare off Oregon

APPENDIX Table 6.— Continued.

Species 64 65 66 67 66 69 70 71 72 73 74 75 76 77 78 79 80 81 62 83 84 85 86 87 88 89 90

S aleutianus

S alutus

S auriculatus

S. aurora

S babcocki

S borealis

S brevispinis x x x x x x x

S caunnus

S chlorostictus

S crameri

S diploproa

S elongatus

S emphaeus

S entomelas x x x

S eos'^

S flavidus

S goodei xxxxxxxxxxxxxx

S helvomaculatus

S lordani x x x x x x

S maliger

S melanops

S melanostomus

S miniatus

S mystinus

S nebulosus

S nigrocinctus

S paucispinis xxxxxxxxxxxxxxxxxxx

S pinniger

S pronger

S rastrelltger

S reedi x x x x

S rosaceus'

S rubemmus

S saxicola

S wilsoni

S zacentrus

46

AERIAL SURVEY OF THE BOTTLENOSED DOLPHIN, TVRSIOPS

TRUNCATUS, AND THE WEST INDIAN MANATEE, TRICHECHUS

MANATVS, IN THE INDIAN AND BANANA RIVERS, FLORIDA

Stephkx Lkathkrwood'

ABSTRACT

Aerial surveys were conducted of the Indian and Banana Rivers, eastern Florida, to estimate numbers
of bottlenosed dolphins and West Indian manatees. Thirty-nine east- west transects, 4.63 km (2.5 n. mi.)
apart, were flown on six successive days in August. Observers at inlets from the ocean inventoried
dolphins and manatees entering or leaving the river during the hours of the surveys. There were 64
sightings of dolphins from aircraft, totaling 507 animals. Fifteen dolphins were seen entering or
leaving the river. Direction of movement within the inlets appeared unrelated to tidal flow. The
population of dolphins in the rivers during the week of the survey 1 10- 15 August 1 977 1 was estimated at
438 ±127. Calves composed 8.1 to 10. Kf of all animals seen. Feeding was observed at widely scattered
times and locations. There were 60 sightings of manatees totaling 151 animals. No attempt is made to
estimate the size of the manatee population. Calves made up 9.9 to 13.2^f of ail manatees seen.

The portion of the intracoastal waterway of east-
ern Florida between about lat, 28'47'N and
27 lO'N consists of the connected waters of the
Indian and Banana Rivers (Figures 1, 2, 3). To-
gether they form a complex waterway just over
185.0 km (100 n. mi.) long and from <0.93 km (0.5
n.mi.) to 9.3 km (5.0 n.mi) wide. Below thejunc-
tion of the two rivers at the southern tipof Merritt
Island (approximately lat. 28'09'30"N), the Indian
River is connected to the adjacent Atlantic Ocean
by boating channels at Sebastian and Fort Pierce
Inlets.

Like many other portions of the intracoastal
waterway, the Indian-Banana River complex is
home to Atlantic bottlenosed dolphin, Tursiops
tnnicatus. Although the numbers of dolphms in-
habiting the rivers is unknown, they have been
rumored to contain as many as 5,000 individuals
(Orr-I. Whatever its actual size, however, this
population is at the center of a grow;ing con-
troversy. Commercial fishermen in the river and
the adjacent ocean report that the dolphins are a
nuisance and menace, annually causing an esti-
mated $441,000 worth of damage to longlines and
trammel nets used in the Spanish and king mack-

'Biomedical Group, Naval Ocean Systems Center, San Diego,
Calif, present address; Hubbs/Sea World Research Institute,
1700 South Shores Road, San Diego, CA 92109.

-Orr. J M 1977 A survey of Tursiops populations in the
coastal United States, Hawaii and Territorial Waters. Contract
Report No PL92-522, to the U.S. Marine Mammal Commission.
Wash., DC, 18 p.

erel fisheries and not infrequent injury to fisher-
men (Cato and Prochaska 1976), The fishermen
have reportedly requested assistance from the
Federal government in controlling the dolphin
populations. (White-M. Recent attempts to use
sounds projected underwater to deter the dolphins
from approaching fishing nets and boats have had
little effect (Caldwell and CaldwelH). Because of
restrictions imposed on the "taking" of marine
mammals by the Marine Mammal Protection Act
of 1972, and concerns about the dolphins' roles in
the ecosystem, any attempts to reduce the alleged
interference of dolphins with the fishing activity
must fall under close scrutiny.

The river complex is also home, at least season-
ally, to some endangered West Indian manatees,
Trichechus manatus. The status of these and other
manatees of the mainland United States has been
most recently reviewed by Hartman'"' and Irvine
and Campbell (1978).

During August 1977, 1 conducted an aerial sur-
vey of Indian and Banana Rivers to estimate the
size and productivity (number of calves) of the
bottlenosed dolphin population. In addition, I took

Manu.^cnpl accfpU'd Aufjust I 97H

FISHKRY mUJ.ETI.N VOL 77. NO 1.1979.

^J. R White, Doctor of Veterinary Medicine, 16501 S.W. 184th
St., Miami, Fla.. pers. common Julv 1977.

^Caldwell, D. K., and M. C. Caldwell. 1975. Dolphins and
fisheries. In A report on the Sea Grant program, p. 28-29. State
University System of Florida

'•Hartman. D. S. 1974. Distribution, status and conserva-
tion of the manatee in the United States. Unpubl. rep in tiles of
U.S. Dep. Inter., Natl Fish Wildl. Lah . Wa.sh . DC , 126 p.

47

nSHERY BULLETIN: VOL 77. NO, 1

advantage of the survey to count manatees and to
note numbers of manatee calves.

MATERIALS AND METHODS

The survey design follows the recommendations
of Leatherwood et al. ( 1978) for a strip census of
bottlenosed dolphins. Thirty-nine east-west
transects were placed 4.63 km (2.5 n.mi.) apart.
Each day for six successive days (10-15 AugustI
the replicate transects were flown in a Cessna 172
Skyhawk'5 travelling 167.0 km/h (90 kn) at an
altitude of 150 m (500 ft).

The visual angle which provided 0.463 km (0.25
n.mi. ) coverage on each side was determined prior
to the survey and marked by tape on the wing
struts and windows. One observer on each side
searched for dolphins within 0.463 km of the air-
craft. Sightings near the outer boundary of the
survey strip were checked using an inclinometer.
Sightings outside the survey strip and on connect-
ing legs were ignored. Each time dolphins were
sighted within the survey strip, the aircraft di-
verted to the group and circled until the following
information could be obtained: location of the
sighting (using landmarks and local navigational
aids), number of individuals, number of apparent
calves of the year, group activity, and swimming
direction.

Each time manatees were sighted, both on the
survey transects and on the legs connecting tran-
sects, the same procedure was followed. Adults
and calves were clearly distinguishable (calves
were defined as small animals in the close com-
pany of a much larger adult). A total of five indi-
viduals of a third class, intermediate-sized ani-
mals, were logged separately as possible older
calves. Because manatees were secondary targets
of the survey, less time was generally spent on
manatee than on dolphin sightings.

As an index to through-water visibility, records
were maintained on 3 days of the percentage of
each transectfor which the bottom within the strip
was visible from the aircraft. To minimize effects
of other potential variables on counts the follow-
ing controls were exercised: all flights were con-
ducted between 0725 and 1300; observers
remained the same and maintained the same posi-
tions in the aircraft; altitude and speed were held
constant; methods of searching and circling were

the same throughout; estimates of totals and
numbers of calves were agreed upon by observers
before each sighting was logged and transects re-
sumed. Surveys were only conducted when the sea
surface and winds were estimated to be a Beaufort
number of 1.5 or below. Because weather was gen-
erally excellent for all 6 days, this required only
one 40-min suspension on 14 August to permit a
rain squall and associated winds to pass. Each day,
during the hours of the aerial surveys, observers
stationed on shore logged numbers of dolphins and
manatees entering or leaving Indian River by
Sebastian and Fort Pierce Inlets and the direction
of travel of these animals relative to tidal flow.

Resultant data on dolphins were analyzed fol-
lowing the procedures outlined by Leatherwood et
al. (1978) for a strip census of bottlenosed dol-
phins. Inherent in the application of this method is
the critical assumption that all dolphin herds
within the 0.926 km (0.5 n.mi.) are observed. Re-
sultant data on manatees are presented as inci-
dental observations with no attempt to estimate
population size.

RESULTS

Dolphins

On each replicate of the transects, I surveyed
approximately 174.0 linear km (94 n.mi.) or 161.2
km^ (47 n.mi. 2) of water, an estimated 20^ of the
surface area of the rivers. In all, 64 sightings of
dolphins, totaling 507 animals (Table 1) were
made on the transects (Figures 1, 2, 3). Sightings
included from 1 to 35 individuals about a mean of
8.2 and a median of 5. The distribution of herd
sizes by replicate is shown in Figure 4.

Animals clearly identifiable as calves of the
year were seen with 22 groups (34.4%) and com-
prised 8.n of all animals seen (Table 1). Slightly
larger animals, perhaps older calves of the year.

T.^BLE 1. — Numbers of herds and individuals of bottlenosed
dolphins observed in Indian and Banana Rivers, Fla.. during
aerial surveys, 10-15 August 1977.

'Reference to trade names does not imply endorsement by the
National Marine Fisheries Service, NOAA.

Total no

Total no, of

Survey no

Total no

of

calves of

(replicaiei

Date

of hefds

individuals

tfie season

t

10 Aug

11

90

6 (6 7%)

2

11 Aug

10

74

7 (9 5%)

3

12 Aug.

16

106

13 (12.3%)

4

13 Aug

7

49

3 (6 1%)

5

14 Aug

7

84

6 (7 1%)

6

15 Aug

13

104

6 (5 8%)

Totals

64

507

41 (8 1%)

48

LEATHERWOOD AERIALSL'RVEY OF DOLPHINS AND MANATEES

28° 55'

45'

40'

35

30'

25"

20'

28°15'

1

PONCE DE LEON INLET

TO

CAPE CANAVERAL

NAUTICAL MILES

CAPE CANAVERAL

Su.-t

No

Dale ol

u.«ev

1

•

Aug 10

1977

2

o

Au9 11

1977

3

▲

Aug 12

1977

4

A

Aug 13

1977

5

Aug 14

1977

6

D

Aug 15

1977

30'

Figure 1.— Indian and Banana Rivers. Fla., indicating locations of transects 1-14 and sightings of herds of bottlenosed dolphins.
Numbers by the symbols indicate numbers of individuals counted. The symbols indicate locales that were contained within the
0.463-km i0,25 nmi.i strips.

49

FISHERY BULLKTIN VOL 77, NO 1

28°15

10

05'

28'

55'

50'

45'

50'

is-

le-

CAPE KENNEDY

TO
BETHEL SHOAL

T r 1 1 I I

UTlCAL MILES

17-

18

Survey

No

Date of

iufvev

1 •

Aug 10

1977

2 O

Aug 11

1977

3 ▲

Aug 12

1977

4 A

Aug 13

1977

5

Aug 14

1977

6 G

Aug 15

1977

45'

SHORE STATION

5 4 'i^^SEBASTIAN INLET

01

80° 20'

Figure 2. — Indian and Banana Rivers, Fla., indicating locations of transects 15-26 and sightings of herds of bottlenosed dolphins.
Numbers by the symbols indicate numbers of individuals counted. The symbols indicate locales that were contained within the
0.463-km (0.25 n.mi.) strips.

were seen with seven groups (10.9^J) and com-
posed 2'~'( of all animals seen. Depending on the
correct classification of these larger animals, total
calves of the year surviving at the time of survey
appeared to range from 8.1 to lO.lCf. The herd

densities (number of herds per square kilometer)
and mean herd sizes ( mean number of animals per
herd) for each replicate and the variances of both
values are summarized in Table 2. The estimated
densities of dolphins were calculated from:

50

LEATHERWOOD AERIAL SURVEY OF DOLPHIN'S AND MANATEES

27° 45'

40'

35'

BETHEL ISLAND

TO
JUPITER INLET

VERO BEACH

30

25

20

15'

10' -

27° 05'

I

I I I

NAUTICAL MILES

SHORE STATION

FORT PIERCE INLET

Survey

No

Date of

ufvev

1 •

Aug 10,

1977

2 O

Aug 11.

1977

3 ▲

Aug 12.

1977

4 A

Aug 13.

1977

5

Aug 14.

1977

6 n

Aug 15.

1977

T LUCIE INLET

80° 20'

55'

FiGL'RE 3. — Indian and Banana Rivers, Fla,. indicating locations of transects 27-39 and sightings of herds of bottlenosed
dolphins. Numbers by the symbols indicate numbers of individuals counted. The symbols indicate locales that were contained
within the 0.463-km iO-25 n.mii strips.

51

FISHERY BULLETIN VOL

Mode

FlGllRK 4. — Distribution of herd sizes
of bottlenosed dolphins for each of the
six replicates.

o

il 2

[ I Survey 1
I — H Survey 2
(^^ Survey 3
['.y\ Survey 4
|§§3 Survey 5
^H Survey 6

N-64

15 20 25

No. of individuals per herd

K±4

30

35

hcl

ll)

where h = mean herd size

a = mean herd density, described as I'zL)
inlw) where L = total length of tran-
sects, n = total sightings, and iv =
the one-sided strip width of 0.463
km (0.2.5 n.mi.l.

The estimated variance of this product (S'^((/)) was
calculated from Goodman (1960):

S-Md) = h-'S-Ha)+ a'S-'(h) - S^iSlS^l/;)

(2)

where h = mean herd size

a = mean herd density
S^(h) = estimated variance of mean herd

size
S'^ta) = estimated variance of mean herd
density.

Feeding was observed in portions of 36'r i23 of
64 ) of the groups encountered and was observed in
all survey periods and areas. Feeding behaviors
were similar to those previously reported for Tur-
siops sp. (Leatherwood 197.5).

There was no correlation between the visibility
index and the number of sightings on any given
transect or set of transects regardless of how data
were grouped (rank correlation with Kendall's
Tau (Conover 1971) at a = 0.05, indicating that
significantly larger numbers of animals probably
were not missed in the most turbid water).

TaBI.F 2. — Herd density 1 number ofherds per square kilometer),
mean herd size (mean number of dolphins per herdi, and dolphin
densities (numbers of dolphins per square kilometer) on each
replicate. Except where noted means and their variances were
calculated over replicates.

Survey no

Date

Herd

Mean

Dolphin

(teplicale)

(1977)

density

herd size

densities

1

10 Aug

068

8 18

0,556

2

11 Aug

062

7 40

0459

3

12 Aug

099

6.63

0.656

4

13 Aug

043

700

0301

5

14 Aug

043

12 00

0516

6

15 Aug

080

800

0640

Means

066

820

521

Variance ol

means

9 204 • lO"

6 35 10-'

1837

Using ailernale method described in text Density estimate of dolphins lih =
542 ((rom Equation ( 1 )) Variance ot density estimate of dolphins S^id) =
094 (from Equation (2))

Manatees

In all I made 60 sightings of manatees, totaling
151 animals (Figures 5, 6, 7). Sightings ranged
from individuals to concentrations of as many as
22 animals with a mean of 2.5. Animals clearly
identifiable as calves were part of 14 of the 60
sightings 123.3'^^ ) and made up 9.9'i (15 of 151 1 of
all manatees seen (Tables 3, 4). Intermediate-
sized animals, possibly yearlings or older calves,
were part of 5 of the 60 sightings iS.'i"! ) and com-
posed 3.3'/ (5 of 151 ) of all manatees seen. If these
intermediate-sized animals were also part of this
year's crop, total number of calves of the year
surviving at the time of the survey may be 13.2'; .

No attempt was made to estimate numbers of
manatees because all manatees were recorded
whether on transects or connecting legs and
whether within or outside the transect strip.

52

LEATHERVVOOD AERIAL SURVEY OF DOLPHINS AND MANATEES

28° 55'

45'

40'

35'

30' -

25

20

28''15' -

80° 55'

Nij

•

Djil' Ql ■.U.vfV

1

•

Aug 10, 1977

2

Aug 11, 1977

3

A

Aug 12. 1977

4

A

AuB 13. 1977

5

Aug 14, 1977

6

D

Aug 15. 1977

PONCE DE LEON INLET

TO

CAPE CANAVERAL

• UTICAL MILES

80° 20

Figure 5. — Indian and Banana Rivers, Fla,. indication locations of transects 1-14 and .sightings of West Indian manatees. Numbers by

the symbols indicate estimated numbers of individuals.

Manatees were often observed in several loca-
tions ( Figures 5,6,7) though the numbers counted
in each location varied among days.

A single dark adult manatee with a diagonal
yellowish slash (perhaps a scar) across the back.

seen 12 August near the east end of transect 3 was
again observed 1-3 August, 200 yd from the east
end of transect 4.

Manatees were sighted in the inlets on four oc-
casions during the survey (Table 3), a group of two

53

FISHERY BULLETIN VOL 77. NO

28° 10'

05

28'

55'

50'

27° 45' -

50'

15

16.

17-

MELBOURNE

18

19-

'jUI V

^

Nr

Date ot s

ufvey

1

•

Aug 10,

1977

2

o

Aug 11.

1977

3

▲

Aug 12.

1977

4

A

Aug 13.

1977

5

Aug 14.

1977

6

D

Aug 15.

1977

45'

40

SHORE STATION

SEBASTIAN INLET

80" 20

FlOL'KK 6. — Indian and Banana Rivers. F"la . indication locations of transects 1.5-26 and sightings of West Indian manatees.
Numbers by the symbols indicate estimated numbers of individuals.

animals milling within Fort Pierce Inlet, a group
of two adult.s moving against the tide, and two
,separate individuals moving with the tide.

Like the dolphins', manatees' movements ap-
peared unrelated to tidal flow within the channels.

DISCXSSION

Dnlphins
The estimated number iil dolphm.^ in the river at

the time of the survey 1 438 ± 127) wasconsiderabl.v
smaller than nni' wnuld have expected for the area
based on the accounts of Cato and Prochaska
I I97Ki and Orr (see fontnute 2i and on discussicms
with fishermen and other residents of the area.
However, the densities of dolphins observed were
generally much higher than those reported from
aerial surveys of the waters of .Alabama, .Missis-
sippi, and Louisiana (Leatherwood et al. 1978)
and the west coast of Florida (Odell and

54

LEATHKRVVOun AERIAL SIRVKV i IH lldl.PHINS \M I MANATEES

27° 45'

40'

35'

30'

25'

20'

15' -

10

27° 05'

28*

BETHEL ISLAND

TO
JUPITER INLET

VERO BEACH

AUTICAL MILES

SHORE STATION

FORT PIERCE INLET

I I I

Sum

'V

Nl

Ojl,' o(

\ur\/i;y

1

•

Aug 10

1977

2

o

Aug 11

1977

3

▲

Aug 12

1977

4

A

Aug 13

1977

5

Aug 14

1977

6

□

Aug 15

1977

ST LUCIE INLET

80° 20

55

Ficl'RE 7, — Indian and Banana Rivers, Fla . indicating locations of transects 27-39 and sightings of West Indian manatees.
Numbers by the symbols indicate estimated numbers of individuals.

55

FISHKRY BULLETIN VOL

T \liLK 3. — Numht*r> (if bcittlenosed dolphins and West Indian manatees entering or leaving the Indian River during the time of the
aerial surveys, indicating direction of travel relative to tidal flow

Dale

11977)

Bottlenosed dolphins

West Indian manatees

10 Aug

1 1 Aug

12 Aug

13 Aug

14 Aug

15 Aug

Total

4 adults moving against tide into river through Sebas-
tian Inlet

7 adults 2 calves moving with tide trom river into
Sebastian Inlet thence against tide back into river

1 adult moving against tide into river through Sebas-
tian Inlet

1 luvenile milling within Sebastian Inlet at slack
tide

15 individuals consisting ol 5 moving against tide
9 moving both with and against tide and i milling
within inlet

2 adults milling within Fori Pierce Inlet

2 adults moving against tide into nver through Fort

Pierce inlet

1 adult moving with tide from river to ocean through

Sebastian Inlet
1 adult moving with tide from river to ocean through

Sebastian Inlet

6 individuals, consisting ol 2 milling withm inlet 2
moving against tide, and 2 moving with tide

T\HLK 4 — Summary of West Indian manatee sightings by day
during the six 1-day aerial surveys. August 1977.

TaHLK 5. — Some estimates of density of bottlenosed dophms,
Tursiops sp., in coastal waters of the southeastern United States.

Survey

Total no ot

Number of an

mals

Calves ol

Other possible

Date

no

sightings

Total

season

calves

10 Aug

1

9

13

H7 6%)

1(0 7»„)

11 Aug

2

12

21

2(9 5%l

1(0 7%)

12 Aug

3

8

18

2(11 1%I

O(-)

13 Aug

4

1 1

18

1(5 6%)

Ot-)

14 Aug

5

11

41

5(12 2°^l

O(-)

15 Aug

6

9

40

4(10 0°o|

3(2 O-'o)

Total

60

151

15(9 9%)

5(3 3%)

Reynolds'i. and were consistent with those re-
ported from aerial surveys conducted in Texas
using similar methodology (Barham et a!.**! (Table
5). This consistency and the relatively low var-
iance estimates are evidence that this was a
realistic estimate of the numbers of dolphins in the
rivers during the time of the survey.

Biittlenosi'd dolphins have been observed to
occur as individuals and in groups of over 200
animals i Leathfruiind and Platter''). Mean herd
sizes iif hdtlleno.sed dolphins off eastern P^lnrida
and in {hv C!ulf of Mexico vary considi'iahiy I'nim
one area to another- ('ii'oups apparently decrease

'Odell. D K.. and J, E Reynolds III In press. Distribution
and abundance of the bottlenosed dolphin. Tursiitps Iruniiitus.
on the west coast of'Florida. Contract Report to the U.S. Marine
Mammal Commission. Wash., D.C., 5.5 p. National Technical
Information Service. Wash.. DC

'Barham. E, G . J, C. Sweeny. S. Leatherwood. R. K Beggs.
and C. L, Barham, 1978, Aerial census of bottlenosed dol-
phins tTursifips truiicatiist in a region of the Texas coast. Un-
publ- manuscr,. 34 p. Southwest Fisheries Center. National
Marine Fisheries Service. NOAA. P.O, Box 271. La Jolla, CA
920.38

"Leatherwood. S,, and M. F, Platter, 1975, Aerial assess-
ment of bottlenosed dolphins off Alabama. Mississippi, and
Louisiana, hi D, K, Odell, D. B, Siniff. and G, H. Waring
ifditorsi. 7\irsiiips tnmcaliis assessment workshop, p, 49-86,
Final Report. U,S, Marine Mammal Commission, Contract
MM5AC021

Dolphin

Dolphins

Location

Reference

per km^

per n mi.^

Mississippi

Leatherwood et al

023

057

gull coast

(1978)

Louisiana

Leatherwood et al

44

1 08

gulf coast

(1978)

Florida'

Odell and Reynolds

23

57

West Coast

(see footnote 7)

Texas

Barham et al (see

65

1 61

gull coast

footnote 8)

Florida

This paper

0.6B

1 77

Indian River

^Derived trom their Table 10 by computing the product ol mean I
(5 43) and mean herd density (0 0497)

in size with distance from shore lOdell and
Reynolds see footnote 7i; tend in coastal waters to
be larger in deeper and in open water areas than in
shallou embaymenls. lagoons, and marshlands
I LeatheiuDod and Platter see footnote 9; Leath-
erwood et al. 1978; Shane and Schmidley'"); and
tend to fluctuate in size seasonally with little pat-
tern discernible i Shane and Schmidley see foot-
note lOi. The mean group size observed during this
stt-id\- IS. 21 \sas well within the limits reported by
all authors for eastern Florida and gulf coast v\a-
ters. This and the lack olcorrelation between herd
size and herd densit\' lurther suppoi't the reason-
ableness of this population estimate (only if the
distribution of herd sizes were normal could the
inference technically lie made that the two vari-
ables were independent (Figure 4ii.

Because the estimation of variance in total
numbers of animals assumes that herd size and

'".Shane, S, H,, and D, J, Schmidley, In press. Population
hiiilogy of .Atlantic bottlenosed dolphins, Tursittpti truncatus, in
the .Aransas Pass area of Texas, Contract Report to the U.S.
Marine .Mammal Commi.ssion. Wash,, DC. 2.'i8 p. National
Technical Inform.itinn .Service. Wash., D.C.

56

LEATHERWOOD AERIAL SURVEY (IF DOLPHINS AND MANATEES

herd density are mutually independent, the data
by day were examined for correlation. Using Ken-
dall's rank correlation coefficient (Conover 1971)
at a = 0.05, mean herd size and mean herd density
were demonstrated to be uncorrelated within the
area surveyed.

The dolphin densities per square kilometer were
then multiplied by the area surveyed and a factor
of 5 (since the survey covered 20' V of the total area)
and the 95'^i confidence limits calculated for the
estimate. The figures support an estimate of
438±127 dolphins for the Indian and Banana Riv-
ers during the time of the survey.

As an alternate method for estimating dolphin
densities, I took the average density over repli-
cates from column 3, Table 2. This procedure re-
sults in a density estimate of 0.40 dolphin km-
(1.36 dolphins/n.mi.^), a value very close to the
estimate obtained using the method described
above (0.41 dolphin km-, 1.41 dolphins/n.mi.^),
but having a variance twice as large (0.1837 vs.
0.0941. Because of the higher variance, it can be
argued that the first method used, because it takes
into account both average herd size and average
herd density, is preferable in this case.

The numbers of dolphins entering or leaving the
river at Sebastian (4 groups totaling 15 animals)
and Fort Pierce Inlets (none sighted) were negligi-
ble and were judged as insignificant to the total
population size. Two of those groups were entering
the river against an outgoing tide, one moved from
the river into the inlet on an ebbing tide, then
turned around and reentered the river, and one
was milling within the inlet (Table 3).

The surprisingly low estimate does, of course,
raise an important question. Is the population of
bottlenosed dolphins in the river complex always
this small (and only appears larger because of
periodic concentrations of animals in limited
areas) or is it augmented seasonally by influxes of
animals from other areas migrating into,the rivers
in response to the movement of fishes?

Caldwell ( 1955) and others have suggested lim-
ited home ranges for bottlenosed dolphins. Wells
et al.," Irvine et al.,'- and Shane and Schmidley

"Wells. R. S.. A, B. Irvine, and M. D. Scott 1977, Home
range characteristics and group composition of the Atlantic
bottlenosed dolphin Tur>ii(>ps tnirtcatus on the west coast of
Flonda. In Proceedings lAbstr.l of the Second Conference on
the Biology of Marine Mammals, San Diego, Calif., 12-15 Dec.
1977, p. l.i

'■^Irvine, A. B., M D, Scott, and R. S Wells, 1977, Move-
ments and activities of Atlantic bottlenosed dolphins. In Pro-
ceedings lAbstr.l of the Second Conference on the Biology of
Marine Mammals, San Diego. Calif, 12-15 Dec. 1977. p. 16.

(see footnote 10) have all clearly demonstiated
limited home ranges for portions of the popula-
tions in their study areas; Wells et al. (see footnote
1 1 ) have shown differences in size and locations of
home ranges based on age and sex classes, and all
these authors have reported some movements ol'
animals into and out of their study areas.

Caldwell and Caldwell (1972) summarize the
views of the fishermen from eastern Florida that
there are "river" and "ocean" T. Iriniciiliis popula-
tions. Caldwell et al. (1975) presented evidence
from the distribution of cases of "Lobos" disease
(lobomycosis) in bottlenosed dolphins that indi-
cate greatest susceptibility to the disease in
riverine-estuarine stocks and suggest isolation of
river from ocean stocks.

Shane''' reported that the offshore population of
bottlenosed dolphins off Texas rarely interacted
with the bay population but that the winter popu-
lation in the Port Aransas area was at least twice
as large as that in summer, because the bay popu-
lation was augmented by "large numbers" of dol-
phins entering that area for the winter either from
the adjacent gulf or from adjacent bay systems.
Whether or not a similar influx occurs in the In-
dian River is unclear. Additional surveys during
the peak seasons of the most important midwinter
fisheries (king and Spanish mackerel, bluefish,
spots, and pompano) might provide answers.

In considering the questions of the dolphins'
population size and alleged damage to nets, it
should be remembered that bottlenosed dolphins,
at least in some areas, are not uniformly distrib-
uted but tend to concentrate in areas of high fish
productivity (Leatherwood and Platter see foot-
note 9) which are often areas of highest human use
(Leatherwood 1975). Irvine et al. (see footnote 12),
for example, reported that short-term movements
of bottlenosed dolphins near Tampa Bay appear to
correlate with movements of mullet. Frequent
joint use of resources by dolphins and humans
make the dolphins highly visible and could result
in inflated estimates of their numbers.

Even if not augmented seasonally by immigra-
tion from other areas, the relatively small dolphin
population in Indian and Banana Rivers could be
responsible for net damage of the types reported by
Cato and Prochaska ( 1976). Feeding by dolphins
near seine and gill net fisheries is well known

'^Shane. S, H. 1977, Population biology of Twr-'iio/w /ra(i-
latus in Texas. In Proceedings (Ab.str.l of the Second Confer-
ence on the Biologvof Marine Mammals. San Diego. Calif. 12-15
Dec. 1977. p. .57. '

57

FISHERY BULLETIN VOL 77, NO 1

( Leatherwood 1975), and dolphins sometimes be-
come entangled as a consequence (Mitchell 1975).
An entangled adult dolphin, struggling for escape,
is certainly capable of ripping a small-mesh net
apart. Further, bottlenosed dolphins have been
documented stealing fish from longlines (Iver-
son'''). Even so, dolphins may not actually be re-
sponsible for all or even the majority of the dam-
age in Indian River. Cato and Prochaska (1976)
refer to damage to nets by sharks and cite the need
for deterrents. D. K. Caldwell'^ reviewed the evi-
dence and concluded that the majority of damage
to nets in the Indian River was probably caused by
sharks and not by dolphins, citing as support
numerous reports by fishermen and others work-
ing the area of sharks around nets. He also con-
cluded, however, that dolphins were stealing fish
and damaging gear in the king mackerel fishery in
the nearby Atlantic Ocean. During the aerial sur-
veys, I observed huge concentrations of sharks on
the sand bars at the entrance of St. Lucie Channel.
Therefore, the question of what causes the damage
to nets is still open and regulation of the dolphin
population based on its supposed size and levels of
damage to the fisheries would be premature.

Irvine et al. (see footnote 12) reported that in
spring calves composed as much as 147^ of the
bottlenosed dolphin population near Tampa Bay.
Shane (see footnote 13) reported that calves con-
stituted from 3.65% (February) to 12.92% (May) of
the dolphins in the Port Aransas area (x = 7.61);
Leatherwood et al. (1978) reported summer
figures from 7.7 to 7.9% calves for coastal Ala-
bama, Mississippi, and Louisiana. The 8.1-10.1%
calves observed during this survey therefore are
well within the reported ranges of percentages of
calves in local bottlenosed dolphin populations.

It has been noted that in areas where tidal flow
is negligible, as is the case within these rivers,
dolphin movements appear to be related to some
factor other than tide (Shane and Schmidley see
footnote 10). Shane and Schmidley found that the
dolphins in areas of swiftest current moved
against tidal flow. The inability to ascertain a
relationship between swimming direction of

'■•Iverson.R, T. B. 1975. Bottlenosed dolpliins stealing fish
from Hawaiian fishermen's lines. Unpubl- manuscr., 12 p.
Southwest Fisheries Center Honolulu Laboratory, National
Marine Fisheries Service. NOAA, P O. Box .3830, Honolulu, HI
96812.

"'D. K. Caldwell. University of Florida, Biocommunication
and Marine Mammal Research Facility. Rt. 1, Box 121, St. Au-
gustine, FL 32084, pers. commun. September 1977.

groups and tidal flow in the river inlets in this
study is perhaps related to our small sample size.

Manatees

Hartman (see footnote 5) and Irvine and
Campbell (1978) reported that Florida manatees
concentrated near warmwater refugia during
winter months but dispersed during the remain-
der of the year. The 151 manatees (some no doubt
repeats on successive days) sighted during this
survey were distributed throughout the nearshore
waters of the Indian-Banana River complex, in-
cluding several less saline canals, and animals
were not concentrated near the St. Lucie power
station or other potential warmwater areas where
winter concentrations have been reported (Irvine
and Campbell 1978). No manatees were observed
in the deeper open water of the rivers. All were in
shallower coastal waters, marinas, creek mouths,
bayous, and canals. The number of calves ob- |
served, composing from 9.9 to 13.2% , depending on
the correct classification of the intermediate-sized
animals observed, falls within the ranges of 9.6%
calves (winter) and 13.4% calves (summer) re-
ported by Irvine and Campbell (1978).

ACKNOWLEDGMENTS

I thank the following for help with this project:
aircraft from Orlando Flying Service, Orlando,
Fla., were flown by Steve Negrich. Glen Young,
Sea World of Florida, flew as second observer. Both
men were very competent and patient with the
arduous flight schedule. Ed Asper,Sea World, Inc.,
provided observers at the ocean inlets and offered
valuable advice on the animals of the river. Leola
Hietala and Louise Anello Irwin typed the manu-
script. D. K. Caldwell, A. B. Irvine, Mari Schaef-
fer, J. Powers, T. J. Quinn, S. Shane, and R. Wells
reviewed the manuscript and made useful sugges-
tions for its improvement. Fishery Bulletin re-
viewers L. L. Eberhardt and J. R. Gilbert were
especially thorough in their treatment.

LITERATURE CITED

Caldwell. D, K

1955. Evidence of home range of an Atlantic bottlenose
dolphin J. Mammal. 36:304-305.
C.-^LDWELL. D. K., AND M. C. CALDWELL,

1972. The world of the bottlenosed dolphin J B Lippin-
cott Co., Phila.. 157 p.

58

LEATHERWOOD AERIAL SURVEY OF DOLPHINS AND MANATEES

Caldwell. D. K.. M. C. Caldwell. J. C. Woodard, L. ajello,

W. KAPLAN, and H. M. MCCLURE

1975. Lobomycosis as a disease of the Atlantic bottlenosed
dolphin ^Tiirsiops truncatus Montagu. 1821), Am J. Trop.
Med. Hygiene 24:105-114.

CATO. J. C, AND F. J. PROCHASKA

1976. Porpoise attacking hool<ed fish irk and injure
Florida fishermen. Natl. Fisherman 56(9i:3B. 16B.

CoNOVER. W. J

1971. Practical nonparametric statistics. John Wiley and
Sons. Inc.. N.Y.. 462 p.

Goodman. L. a.

I960. On the exact variance of products. J. Am Stat As-
soc. 55:708-713.
IRVINE. A. B.. AND H. W. CAMPHKLI.

1978. Aerial census of the West Indian manatee.

Truhi'ihiis fuanaliis, in the southeastern L'nited .States
J. Mammal .59:613-617.

LKATHERWOOD S.

1975. .Some observations of feeding behavior of bottle-
nosed dolphins iTursiops trutn-atus) in the northern Gulf
of Mexico and iTurxiops cfr.gi//;) off southern California.
Baja California, and Nayarit. Mexico. Mar. Fish. Rev.
37l9l:10-16

LKATHERWOOD S. J. R. GiLHKUT .WD D. G. CHAI'MAN

197H. An evaluation of some techniques for aerial censuses
of bottlenosed dolphins. J, Wildl. Manage 42:239-2,50.
MlTi HKl.L E

1975. Porpoise, dolphin and small whale fisheries of the
world: status and problems. Int. Union Conserv. Nat..
Monogr. 3. 129 p

59

DEVELOPMENT OF PELAGIC LARVAE AND POSTLARVA OF

SQUILLA EMPilSA (CRUSTACEA, STOMATOPODA), WITH AN

ASSESSMENT OF LARVAL CHARACTERS WITHIN THE SQUILLIDAE

Stkvkn G. Moki;an' anu Anthony J. Pkuvkn/.ano, Jh.'

ABSTRACT

Larvae of the predator\' crustacean .S't/fn/Za enipusa were collected from the plankton in Chesapeake
Bay and reai^ed in the laboratory to permit description of the pelagic stages before the postlarval stage.

Characters such as rostral length and spinulation, carapace spinulation. relative size of telson,
overall body size, and appearance probably are of more value for specific than for generic identification-
The presence or absence of teeth on the dactylusof the second maxilliped. the presence or absence of a
spine on the basis of the second maxilliped. and the number of epipods may be useful characters in
determining generic alliances of larvae belonging to the Squill idae, but present data are not adequate
for construction of generic keys to stomatopod larvae.

Mantis shrimps are formidable predators, able to
slice a swimming shrimp in half or smash open a
bivalve with enlarged second maxillipeds (Mac-
Ginitie and MacGinitie 1968). Even though the
strike occurs under water, it is one of the fastest
movements known in the animal kingdom taking
4 to 8 ms to complete and traveling at a velocity of
1,000 cm/s (Burrows 1969). Basically, any animal
of appropriate size may fall prey to a stomatopod
including fish, shrimp, crabs, annelids, clams,
mussels, snails, squids, and echinoderms (Pic-
cinetti and Manfrin 1970).

Stomatopod larvae are often met with in great
swarms, particularly in tropical waters. The
planktonic larval stages constitute a considerable
portion of the diet of reef fishes and commercially
important pelagic fishes such as the tunas, skip-
jack tuna, mackerel, herring, and snapper iSunier
1917; Fish 1925; Reintjes and King 1953; Randall
1967; Dragovich 1970).

Squilla cntpusa Say 1818 is found in the western
Atlantic Ocean and ranges from Mass'achusetts,
U.S.A. to northern South America, including
Trinidad. Venezuela, Surinam, and French
Guiana (Manning 1969). It is abundant through-
out its range, but is especially prevalent in com-
mercial shrimp beds, and is believed to be a serious
predator of the shrimp Hildebrand (1954) ob-

'Institute of Oceanography, Old Dominion University, Nor-
folk, Va.; present address: Institute of Marine Science, Univer-
sity of North Carolina, Morehead City, NC 28.557,

^Institute of Oceanography, Old Dominion University, Nor-
folk, VA 23508.

Manuscript accepted August 1978

FISHERY BUl.I.ETI.N VOL. 77, NO 1. 1979

served that it is the most abundant crustacean in
the offshore trawl fishery of the Gulf of Mexico
except for Penacus sp. and Ccilli nectes sp,
Stomatopods are fished and eaten in most
Mediterranean countries, Japan, and the tropical
Pacific (Kaestner 1970).

Like the adult, the larvae of S. cnipusa are
rapacious predators. Able to attain a length of 17
mm, they can capture zooplankters as large as
themselves by using their second maxillipeds
(Lebour 1924). Squilla enipiisa larvae not only fill
a role as predators, but also as prey. To date very
little has been published on the ecology of the
larvae nor has the sequence of pelagic stages been
established for this species.

Of the 350 known species of stomatopods. only 1
in 10 can be identified with their larvae and only 1
has been reared from hatching to metamorphosis.
Difficulty in rearing the larvae has forced inves-
tigators to base their accounts on reconstructions
made from preserved specimens or from holding
planktonic larvae through one ecdysis to connect
successive stages. The species of stomatopods for
which larvae are definitely known by the rearing
of late stage larvae through metamorphosis were
listed by Provenzano and Manning (1978).
Stomatopod species for which larvae are definitely
known by the hatching of eggs also are listed by
Provenzano and Manning.

The only description of the developmental se-
quence of S. enipusa was made almost 100 yr ago
by Brooks (1878) who captured larvaeat Fort Wool
near the mouth of the Chesapeake Bay. Because

61-

-io

FISHERY BULLETIN: VOL. 77, NO 1

none of Brooks' larvae metamorphosed into post-
larvae, he could not be sure of their identity. How-
ever, of the thousands he collected, all appeared to
Brooks to be "specifically identical" and the series
of forms were so complete with the differences
between the successive stages so slight that he
concluded there was "no reason to doubt that they
are all of the same species, and that species the
only one which is known to occur in the
Chesapeake Bay." However, we now know that
early larval stages of at least one other species of
stomatopod occur at the mouth of Chesapeake Bay
(Provenzano and Goy, pers. obs.) Brooks' descrip-
tion is inadequate to permit stages to be
adequately assigned to larvae.

Brooks apparently was unable to obtain success-
ful molting in his larvae, but instead had to rely on
reconstruction to describe the larval history. He
provided no conjecture as to the number of pelagic
stages, and only partially described four stages.
Furthermore, the illustrations which Brooks in-
cluded were of whole specimens only; detailed
figures of appendages, necessary for accurate
species identification, were not made.

Faxon (1882), working in Rhode Island, held
what he considered to be the last pelagic stage of S.
empusa until it metamorphosed and could be iden-
tified. However, the last stage larva and postlarva
appear to belong to another species, notS. empusa
(see Discussion).

In this paper we describe the pelagic larval de-
velopment and postlarval stage of S. empusa. Be-
cause egg masses were not collected, hatched, and
reared, the propelagic stages remain undescribed.
Furthermore, because larvae were obtained from
the plankton, we are not positive that the larvae
described as stage I are the true first pelagic stage.
However, of the hundreds of larvae collected these
stage I larvae are the least developed and closely
resemble stage I larvae of other species reared
from eggs.

A brief review of previous efforts to associate
stomatopod larvae with adults and a discussion of
possible specific and generic larval characters
within the Squillidae is presented.

METHODS

Larval specimens of S. empusa were collected
weekly 1 to 2 km north of Cape Henry at the mouth
of the Chesapeake Bay where we have determined
that a population of adults exists. A Vz-m plankton
net ( 153-/xm mesh) was used to make 10-min

stepped oblique tows, as the ship circled the collec-
tion site at idle speed.

Each plankton sample was placed into one or
two 1.9-1 (Va-gal) jars filled with sea water until
stomatopod larvae could be separated from the
sample. Separation of larvae from the samples was
started aboard ship and completed in the labora-
tory. Larvae were sorted according to size to
minimize cannibalism, and held temporarily in
aerated 1.9-1 jars filled with seawater.

The larvae were then placed in compartmen-
talized plastic trays, one per compartment. Each
tray contained 18 compartments measuring 4.5 x
5x4 cm. Medium for rearing the larvae was made
from Instant Ocean Synthetic Sea Salts^ (Aqua-
rium Systems, Inc., Eastlake,Ohio) and tapwater.

Larvae were reared over a range of tempera-
tures ( 10° to 25°C ) and salinities ( 10 to 35%o) in an
attempt to insure survival of at least some larvae
since optimum conditions were unknown. Because
the larvae were not hatched in the laboratory
under the temperature-salinity combination at
which they were reared, some larvae had to be
acclimated to the test conditions. Lavae were
never acclimated to temperature changes of more
than 5°C and 10%o/day. The larvae were main-
tained in total darkness except for brief periods ( 15
to 20 min/day) when they were examined and
transferred to newly prepared trays.

Each larva was reared in 25 ml of water and
given approximately 30 Artemia salina nauplii/ml
daily. Decapod larvae and A. salina, grown on
yeast or an algal culture ofDunaliella, were fed to
larvae that became too large to capture or obtain
substantial nutrition from the A. salina nauplii.
Larvae were transferred daily, early stages by
means of a pipette, later stages with a spoon, into
compartments containing freshly prepared sea-
water and food. During this transfer, frequency of
molting, duration of larval development, survival,
and the stage of development were recorded. Dead
larvae were preserved in 709c ethyl alcohol and
10% glycerin. Preserved larvae were heated in a
59c potassium hydroxide solution to dissolve the
tissue so that only the exoskeleton remained. The
larvae were then stained in acid fuchsin red to
facilitate description and illustration. Larvae and
exuviae were dissected in lactic acid. All larval
appendages were illustrated using a Tasco camera
lucida on a Unitron binocular compound scope,

^Reference to trade names does not imply endorsement by the
National Marine Fisheries Service, NOAA.

62

MORGAN and PROVENZANO; DEVELOPMENT OF SQUILLA EMPUSA LARVAE AND POSTLARVA

while the postlarval appendages were illustrated
with the aid of a Bausch and Lomb microprojector.

The descriptions of all larval stages were based
on five specimens; four specimens were used to
describe the postlarva. Carapace length (CL) indi-
cates the distance from the tip of the rostrum to the
median posterior margin of the carapace, exclu-
sive of the median spine; telson length itL), dis-
tance from the articulation with the sixth abdom-
inal somite to the median posterior margin of the
telson. The term pleotelson (Kaestner 1970) is
used to refer to the telson before the sixth abdomi-
nal somite has become completely articulated.
Pleotelson length (PL) indicates the distance from
the articulation with the fifth abdominal somite to
the median posterior margin of the pleotelson; tel-
son width iTW) and pleotelson width (PW), dis-
tance across the widest portion; rostral length
(RL) of the larva, distance from the tip of the ros-
trum to the base of the anterolateral spines of the
carapace; rostral length of the postlarva, distance
from the tip of the rostrum to the posterior margin
of the rostrum; rostral width (RW) of the post-
larva, distance from the tip of the rostrum to the
median posterior margin of the telson; and total
length (TL) of the postlarva, distance from the
anterior margin of the rostrum to the median
posterior margin of the telson.

Maxillules, maxillae, pleopods. distal spinules
of the rostrum, and most epipods were omitted
from illustrations of the whole animal for the sake
of clarity.

RESULTS

The pelagic larval development of S. empusa
was found to include nine stages before the post-
larval stage. Juvenile stages reared for several
months after metamorphosis attained sizes of ap-
proximately 30 to 40 mm TL and could be posi-
tively identified with the adult. Although none of
the 576 larvae reared at the 16 different tempera-
ture and salinity combinations was reared
through the entire pelagic development to
metamorphosis, larvae survived well and molted
frequently at two of the test combinations. Of lar-
vae kept at 20'C, 25%o salinity, or at 25°C, 25%o
salinity, 47'* molted three or more times, 24%
underwent at least five ecdyses, and 'y^r molted
seven times over a 6-wk period. Thirty-four ani-
mals molted to postlarva. Great increases in size
from the first to the last stage necessitated ad-
justments in food size and quantity. Detailed re-

sults of effects of various experimental conditions
are being prepared by Morgan for publication
elsewhere.

The difficulty in rearing the larvae through the
lengthy pelagic development made it necessary to
reconstruct the developmental sequence by ob-
serving the larvae molt through successive stages.

Stage I (Figure I A)

Measurements (mm): RL, 0.70 to 1.10; PL, 0.4
to 0.8; TL. 2.9 to 3.3; CL, 0.80 to 1.30; PW, 0.3 to
0.6.

Rostrum deflexed, extending slightly beyond
antennular flagella, ventral spinules absent.

Carapace with one pair of supraorbital spines.
Lateral margins of carapace convex, armed ven-
trally with four spinules. Posterior margin of
carapace deeply notched, armed with a median
dorsal spine. Posterolateral spines, armed with
one ventral spinule, extending to fourth abdomi-
nal somite.

Ocular somite articulated, armed with one spine
on median ventral margin. Antennular somite not
articulated.

Antennule (Figure 2Al with long two-
segmented inner flagellum, apical segment armed
with one strong and one weak seta distally and a
pair of weak setae medially, proximal segment
armed with one strong and two weak setae dis-
tally. Outer flagellum armed with one large and
one small seta distally, followed by one weak seta
and six aesthetascs arranged 1-2-3 along inner
margin. Median flagellum absent.

Antenna (Figure 3A) armed with nine plumose
setae, endopod absent.

Mandible (Figure 4A) serrate, mandibular palp
absent.

Maxillule ( Figure 5A ) with coxal endite bearing
three spinules and one seta, basal endite with one
strong tooth flanked by two strong setae, palp with
one long seta, endopod absent.

Maxilla (Figure 6A) unsegmented. armed with
six setae.

First maxilliped (Figure 7A) with dactylus
small, pointed. Propodus with two extremely mi-
nute spinules, inner margin bearing seven strong
setae arranged 2-3-2. Carpus with one strong seta
distally. merus without setae, epipod absent.

Second maxilliped (Figure 8A) large, basis with
stout proximal spine. Propodus with 1 strong ter-
minal tooth followed by 17 to 20 denticles on inner
margin. Dactylus armed with spinules, distal

63

FISHERY BULLETIN VOL, 77. NO. 1

FlGI'RE \ —Squilla cmpusa . A-C . siages\-U
respectively, ventral views.

64

MORGAN and PROVENZANO: DEVELOPMENT OF S^f/i-tA EMPUSA LARVAE AND POSTLARVA

Figure 2.Squilla empusa. A-I:
stages I-IX respectively, antennules.

65

FISHERY BULLETIN VOL, 77. NO 1

1 A 1

II ISmm

1 B-D 1

25mm

1 E-l 1

Figure 3. — Squilla empusa, A-I: stages MX respectively, antennae.

66

MORGAN and PROVENZANO: DEVELOPMENT OF SQUILLA EMPUSA LARVAE AND POSTLARVA

A-D
Imin

_E I

iF-l I
Imri-.

Figure 4. — Squilla empusa, A-I: stages MX respectively, mandibles.

Figure 5.— Squilla empusa, A-I: stages MX respectively, maxillules

67

FISHERY BULLETIN VOL. 77. NO I

Kl(;i'HK 6. — Squilla empiisa, A-I: stages I-IX respectively, niaxilUu

portion of cutting edge minutely serrate. Epipod
present.

Third, fourth, and fifth maxillipeds absent.

Fereiopods absent.

Posterolateral angles of pleomeres rounded,
Pleopods (Figure 9A to 9D) one through four pres-
ent with appendix interna. Pleopod setation of this
and other larval stages presented in Table 1.

Sixth pleomere not articulated, subinedian
spines absent, uropods absent.

Pleotelson (Figure lOAi with paired lateral, in-
termediate, and posterolateral spines, 4 pairs of
intermediate denticles, 15 subinedian denticles
bearing spinules.

68

Stage II (Figure IB)

Measurements (mm): RL, 1,.'J5 to L.'S.'i; PI,.
0.70to0.90;TL. 4.2()to4.60;CL, 1.05 to 1.30; P\V,
0.55 to 0.75,

Rostrum extending wel I beyond end of antennu-
lar flagellum, armed with one to four ventral
spinules.

Carapace slightly convex, posterolateral spines
extend to anterior section of telson.

Antennule (Figure 2B) as in previous stage.

Antenna (Figure .3Bi with 10 to 13 plumose
setae, endopod present as incipient bud.

MORGAN and PROVENZANO DEVELOPMENT OF SQU I LLA EMPUSA LARVAE AND POSTLARVA

Figure 7. — Squilla empusa. A-I: stages MX respectively, first maxillipeds.

69

FISHERY BULLETIN VOL 77, NO 1

1

A-C 1

5mm

1

D-E 1

Smm

F-l ,

Figure S.—Squilla empusa. A-I: stages MX
respectively, second maxillipeds.

70

MORGAN and PROVENZANO DEVELOPMENT OF SQUILLA EMPUSA LARVAE AND POSTLARVA

Figure 9. — SquUla empusa, A-D. stage I, first to fourth pleopods respectively. E-I: stage II, first to fifth

pleopods respectively.

71

FISHERY BULLETIN VOL 77, NO 1

Table i.

— Number

ofsetae on margins of pleopods fur pelagic la

rval stages

I to IX of

Squilla

empusa.

Fifth pleopod does

not appear

until

stage V.

Abdominal somite

EndoDod

Exopod

stage

1

2

3

4

5

1

2

3

4

5

1

6

6

6-7

6-7

_

7

7

7-9

7-9

_

II

6

7-8

7-8

7

_

7-8

9-10

9-11

9-10

—

III

8-10

9-13

10-14

9-14

—

9-10

12-13

13-14

11-14

—

IV

12-13

14-15

15-16

15-17

_

12

16-17

17-18

16-17

_

V

14-15

15-18

16-18

15-20

—

14-15

17-19

19-20

18-19

7-8

VI

16-20

18-25

20-27

20-27

3-8

15-20

21-26

23-29

21-27

12-16

VII

22-28

26-28

26-31

26-32

23-28

22-30

26-31

29-33

28-31

20-23

VIM

25-29

27-32

28-36

31-38

30-39

24-30

32-36

32-38

31-38

24-31

IX

27-31

32-39

35-42

36-45

40-47

36-41

36-41

38-46

37-45

33-39

Mandible (Figure 4B), maxilluie (Figure 5B),
maxilla (Figure 6B), and first maxilliped (Figure
78) as in previous stage.

Second maxilliped (Figure 8A) with propodus
bearing proximal tooth followed by another large
tooth and 19 to 21 denticles along inner margin.

Pleopods one through four (Figure 9E to 9Ht
increase setation slightly (Table li. Fifth pleopod
(Figure 91) present as bifurcated bud.

Pleotelson (Figure lOB) as in previous stage.

Stage 111 (Figure 2C)

Measurements (mm): RL. 1.90 to 2.10; PL.
1.00 to 1. 10; TL, 5.80 to 6.50; CL, 1.50 to 1.78; PW,
0.75 to 0.95.

Rostrum with four to eight spinules ventrally
for stages III to VIII.

Carapace with lateral margins straight, armed
with two anterior and three posterior spinules all
ventrally directed, and one median spinule later-
ally directed. Posterolateral spines extend to pos-
terior region of pleotelson.

Antennule (Figure 2C) with two-segmented
inner flagellum, proximal segment armed with
one strong distal seta. Outer flagellum two-
segmented with 9 or 10 mesial aesthetascs ar-
ranged in three groups of 2 or 3, each group with a
weak seta.

Antenna (Figure 3C) with 13 to 16 plumose
setae, length of unsegmented endopod increased.

One median ventral spine situated between
base of antennules and antennae.

Mandible (Figure 4C) essentially unchanged.

Maxilluie ( Figure 5C ) with coxal endite bearing
four to eight teeth.

Macilla (Figure 6C) with six to eight setae.

First maxilliped (Figure 7Cl with 9 or 10 strong
setae arranged in four groups of 2 or 3 on propodus,
carpus with 1 or 2 strong setae distal ly.

Second maxilliped (Figure 8C) with propodus
bearing 23 to 27 denticles, basis with proximal

72

spine well developed.

Third maxilliped present as bud.

Pleopods one through four (Figure HA to IID)
increase setation (Table 1). Fifth pleopod (Figure
HE) biramous, nonsetose.

Sixth pleomere partially articulated, one pair of
small submedian spines present. Uropods (Figure
IOC) present as buds.

Pleotelson (Figure IOC) with 8 to 10 pairs of
intermediate denticles, including 1 pair in axis of
intermediate spines 15 to 27 submedian denticles.

Stage IV (Figure 12)

Measurements (mm): RL, 2.50 to 2.90; PL,
1.20 to 1.40; TL, 6.50 to 6.90; CL, 1.80 to 2.25; PW,
1.00 to 1.20.

Rostrum with a row of minute spinules distally
for stages IV to VIII.

Antennule (Figure 2D) with three-segmented
inner flagellum armed with two strong setae on
distal half of proximal segment. Outer flagellum
divided into a two-segmented median flagellum,
and a broader outer flagellum with 10 or 11 aes-
thetascs arranged in four groups of 2 or 3, a small
seta with each group. Antennular somite articu-
lated.

Antenna (Figure 3D) with 17 to 19 plumose
setae, length of unsegmented endopod increased
slightly.

Mandible (Figure 4D) essentially unchanged.

Maxillule( Figure 5D) with coxal endite bearing
seven to nine teeth, palp with two setae.

Maxilla (Figure 6D) with eight to nine setae.

First maxilliped (Figure 7D) with 12 or 13
strong setae arranged in five groups of 2 or 3 on
propodus, carpus with 4 distal setae, merus with 1
strong distal seta.

Second maxilliped (Figure 8Di with propodus
bearing proximal tooth followed by 2 strong teeth
in opposition and 25 to 33 denticles along inner
margin.

MORGAN and PROVENEANO; DEVELOPMENT OF SQUILLA EMPUSA LARVAE AND POSTLARVA

FIGURE 10— Squilla empusa. A-I, stages
I-IX respectively, tail fans. Setae omitted
from uropods of stage IX.

73

FISHERY BULLETIN VOL 77. NO 1

Figure II. — Squilla empusa, A-E: stage III, first to fifth pleopods respectively, F-J: stage IV. first to fifth pieopods respectively.

Third, fourth, and fifth maxi II ipeds (Figure 13A
to 1.3C) unsegmented buds,

Pereiopodsl Figure 14Ato 14C) present as buds.

Posterolateral angles of pleomeres acute,
Pleopods one through four (Figure IIF to 111) in-
crease setation. Fifth pleopod (Figure IIJ) setose
and possessing appendix interna.

Sixth abdominal somite articulated, Uropods
(Figure lOD) biramous,

Pleotelson (Figure lOD) with 1 denticle in axis
of lateral spine, 8 or 9 pairs of intermediate denti-
cles, 23 to 30 submedian denticles.

Stage V (Figure 15)

Measurements (mm): RL. 2.50 to 3.25; PL,
1,50 to 1.65; TL, 8.50 to 9.00; CL, 2.30 to 2.50; PW,
1.40 to 1.60.

Antennule (Figure 2E) with three-segmented
inner flagellum armed with two to four setae on
distal half of proximal segment; median flagellum
also three-segmented.

74

Antenna (Figure 3E) with 19 to 23 plumose
setae, length of unsegmented endopod now nearly
equal to segments bearing it.

Epistome with small apical spine.

Mandible (Figure 4E) essentially unchanged.

Maxillule (Figure 5E) with coxal end ite bearing
8 to 12 teeth.

Maxilla (Figure 6E) with 10 or 11 setae.

First maxilliped (Figure 7E) with 13 to 17
strong setae arranged in five or six groups of 2 to 4,
carpus with 5 to 8 distal setae.

Second maxilliped (Figure 8E) with propodus
armed with 30 to 43 denticles.

Third, fourth, and fifth maxillipeds (Figure 13D
to 13F) still unsegmented, but increased in length,

Pereiopods( Figure 14D to 14F) present as bifur-
cated buds.

Uropods (Figure lOE) with basal prolongation
present,

Pleotelson (Figure lOE) with 8 to 10 pairs of
intermediate denticles, 28 to 33 submedian denti-
cles.

MORGAN and PROVENZANO: DEVELOPMENT OF SQUILLA EMPUSA LARVAE AND POSTLARVA

Figure 12. — Squilla empusa, stage IV, ventral view.

Stage VI (Figure 17 A)

Measurements (mm): RL, 3.00 to 3.50; PL,
1.65 to 2.00; TL, 9.80 to 10.60; CL, 2.65 to 2.95;
PW, 1.45 to 1.75.

Antennule (Figure 2F) with four-segmented
inner flagellum. Median flagellum with three
segments. Outer flagellum with 12 to 14 aes-
thetascs arranged in four groups of 2 or 3, each
group with a seta.

Antenna (Figure 3F) with 22 to 25 plumose
setae, endopod now two-segmented.

Mandible (Figure 4F) essentially unchanged.

Maxillule (Figure 5F) with coxal endite bearing
10 to 12 marginal teeth and 1 or 2 very short
medial setae, palp well developed, armed with 2
setae.

Maxilla (Figure 6F) five-segmented, subproxi-
mal segment with endite bearing 14 to 19 setae.
Palp articulated.

First maxilliped ( Figure 7Fi with 18 to 22 strong
setae arranged in six or seven groups of 2 to 4 on
propodus, carpus with 8 to 12 distal setae, con-
spicuous epipod present.

Second maxilliped (Figure 8F) with 33 to 47
denticles along inner margin of propodus.

Third maxilliped (Figure 13G) with endopod
four-segmented, dactylus not reflected against
propodus.

Fifth maxilliped (Figure 131) with endopod un-
segmented.

Pereiopods (Figure 14G to 151) unsegmented,
distally bifurcate, increased in length.

Pleopods one through five (Figure 16F to 16J)
with gills present as buds on inner proximal mar-
gin of exopod.

Uropods (Figure lOF) with basal prolongation
half length of endopod. exopod with or without one
spine on outer margin.

Pleotelson (Figure lOF) with 8 to 10 pairs of
intermediate denticles. 29 to 33 submedian denti-
cles.

Stage VII (Figure 17B)

Measurements (mm): RL. 3.20 to 3.70; PL,
2.00 to 2.20; TL, 11.60 to 13.60; CL. 2.85 to 3.55;
PW, 1.85 to 2.30.

Antennule (Figure 2G) with seven-segmented
inner flagellum, median flagellum five-
segmented, outer flagellum with 18 or 19 aes-
thetascs arranged in five or six groups of 2 or 3,
each with a seta.

Antenna (Figure 30) with 32 to 39 plumose
setae, endopod with three segments.

Mandible (Figure 40) essentially unchanged.

Maxillule (Figure 5G) with coxal endite bearing
13 marginal teeth and 2 medial setae, endite with
spine flanked by 1 strong seta. Palp unchanged.

Maxilla (Figure 60) four-segmented, the two
more proximal segments each with one endite.
Maxilla armed with 32 to 34 setae.

First maxilliped (Figure 70) with 23 to 26
strong setae on propodus, in seven or eight groups
of 2 to 4. carpus with 21 to 27 setae.

Second maxilliped (Figure 80) with 52 to 60
denticles along inner margin of propodus.

Third, fourth, and fifth maxillipeds (Figure 13J
to 13L) fully articulated.

Third maxilliped (Figure 13J) with dactylus
armed with spinules and reflected against prop-
odus, latter armed with 10 or 11 spinules. carpus
with 4 to 6 spinules.

75

FISHERY BULLETIN VOL 77. NO 1

FKUIRK 13.— Squilla empusa, A-C: stage IV,
third to fifth maxillipeds respectively; D-F:
stage V. third to fifth maxillipeds respec-
tively; G-I: stageVI, third to fifth maxillipeds
respectively; J-L: stage VII. third to fifth
maxillipeds respectively; M-O; stage VIII.
third to fifth maxillipeds respectively; P-R;
stage IX, third to fifth maxillipeds respec-
tively.

76

MORGAN and PROVENZANO DEVELOPMENT OF SQUILLA EMPUSA LARVAE AND POSTLARVA

lA-Fi

OOSmn

1 G

-' 1

1

mm

1 J-

O 1

21

1 P-

R 1

s

Tim

FIGURE 14.—Sqmlla empusa. A-C: stage IV. first to third pereiopods respectively; D-F: stage V,
first to third pereiopods respectively; G-I: stage VI. first to third pereiopods respectively; J-L: stage
VII, first to third pereiopods respectively; M-0: stage VIII, first to third pereiopods respectively;
P-R: stage IX, first to third pereiopods respectively.

Fourth maxilliped (Figure 13K) with dactylus
armed with spinules and partially reflected
against propodus, latter armed with four to eight
spinules, carpus with four to six spinules, epipod
present.

Fifth maxilliped (Figure 13L) segmented, dac-
tylus unarmed and not reflected against unarmed
propodus, carpus with zero to three spinules.

Pereiopods (Figure 14J to 14L) with, clearly dif-
ferentiated endopods and exopods. though seg-
mentation not yet distinct.

Pleopods (Figure 18A to 18E) with bilobed
rudimentary gills.

Sixth pleomere partially separated from telson.
Uropods (Figure lOG) with basal prolongation
acute. Exopod with one or two spines on outer
margin, armed with zero to five plumose setae.
Endopod with zero to two plumose setae.

Pleotelson (Figure lOG) with 9 or 10 pairs of
intermediate denticles, 32 to 35 submedian denti-
cles.

Stage VIII (Figure 19)

Measurements (mm): RL, 3.25 to 3.45; tL, 2.30
to 2.50; TL, 13.90 to 15.30; CL, 3.90 to 4.35; TW,
2.25 to 2.65.

Antennule (Figure 2H) with inner flagellum
bearing 9 to 11 distinctly articulated segments.
Median flagellum with five to seven distinct seg-
ments. Outer flagellum with 21 to 23 aesthetascs
arranged in six or seven groups of 2 or 3, each
group with a seta in addition.

Antenna (Figure 3H) with 40 to 55 plumose
seta.

Mandible (Figure 4H) essentially unchanged.

Maxillule ( Figure 5H) with coxal endite bearing
15 to 19 marginal teeth and 2 to 4 medial setae,
distal margin of basis with 1 median seta.

Maxilla ( Figure 6H) armed with 40 to 58 setae.

First maxilliped (Figure 7H) with 29 to 31
strong setae on propodus arranged in eight groups
of 2 to 5, carpus with 37 to 44 setae.

77

FISHERY BULLETIN VOL 77. NO 1

Figure 15, — SquUla empusa. stage V. ventral view.

Second maxilliped (Figure 8H) with 61 to 75
denticles on propodus.

Third, fourth, and fifth maxillipeds ( Figure 13M
to 130i with dactylus armed with spinules and
reflected against propodus, epipods present.

Third maxilliped (Figure 13M) with propodus
armed with 12 to 21 spinules, carpus with 6 to 9
spinules.

Fourth maxilliped (Figure 13N) with propodus
armed with 12 to 16 spinules, carpus with 5 to 8
spinules.

Fifth maxilliped (Figure 130) with propodus
armed with 6 to 11 spinules, carpus with 4 to 7
spinules.

78

Pereiopods (Figure 14M to 140) with two-
segmented exopods, endopods shorter, unseg-
mented.

Pleopods ( Figure 20A to 20E) with trilobed gills.

Sixth abdominal somite completely separated
from telson. Uropods (Figure lOH) with two-
segmented exopod. Basal segment with 2 to 4
spines on outer distal margin, apical segment with
4 to 14 plumose setae on distal margin. Endopod of
uropod with four to eight plumose setae on distal
margin.

Telson (Figure lOH) with 10 pairs of inter-
mediate denticles and 31 to 35 submedian denti-
cles.

Stage IX (Figure 21)

Measurements ( mm): RL, 2.40 to 4.50; tL, 2.30
to 2.60; TL, 13.00 to 17.50; CL, 3.00 to 3.90; TW,
2.10 to 2.80.

Rostrum with decrease in number of spinules,
now with two to six spinules; with or without mi-
nute distal spinules.

Antennule (Figure 21) with inner flagellum
bearing 14 to 20 distinctly articulated segments.
Median flagellum with 8 to 11 distinctly articu-
lated segments. Outer flagellum with 23 to 33
aesthetascs arranged in seven to nine groups of 2
to 7, each group with a seta.

Antenna (Figure 31) with 48 to 60 plumose
.setae, endopod with 6 to 9 segments.

Mandible (Figure 41) essentially unchanged.

Maxillule (Figure 51) with coxal endite bearing
20 to 25 marginal teeth and 1 or 2 medial setae,
margin of basal endite with 1 or 2 setae.

Maxilla (Figure 6U) with 78 to 131 setae.

First maxilliped (Figure 71) with 35 to 44 setae
arranged in 9 or 10 groups of 2 to 5, carpus with 59
to 107 setae, dactylus with or without cluster of
setae on median outer margin, propodus with or
without cluster of setae on distal outer margin.

Second maxilliped (Figure 81) with 71 to 92 den-
ticles on propodus.

Dactylus of third, fourth, and fifth maxillipeds
(Figure 13P to 13R) with or without regularly
spaced setae along outer margin, propodus with or
without a cluster of setae on distal outer margin.

Third maxilliped (Figure 13P) with propodus
bearing 19 to 56 spinules, carpus with 11 to 22
spinules.

Fourth maxilliped (Figure 13Q) with propodus
bearing 17 to 51 spinules, carpus with 10 to 28
spinules.

MORGAN and PROVENZANO: DEVELOPMENT OF SQUILLA EMPUSA LARVAE AND POSTLARVA

-^

■s

a

i

>

<

f

a

79

KiSHKKV BULLETIN' VOL

FlGl'RE 11 ^Sqiiilla emptisa. A-B:
stages VI and VII respectively, ventral
views.

Fifth maxilliped (Figure 13Ri with propodus
bearing 18 to 40 spinules, carpus with 9 to 20
.spinules.

Pereiopods (Figure 14P to 14Ri slender with or
without distal segment of e.xopods setose.

Pleopods (Figures 22A to 22C; 23A. 23Bi with
distal lobe of gill pinnate.

Uropod (Figure 26C) with basal segment ol'
exopod armed with 6 to 8 spines, apical segment of
exopod with 17 to 60 plumose setae. Endopod of
uropod with 10 to 38 plumose setae. Inner spine of
basal prolongation with blunt spine on outer prox-
imal margin. Basal uropod segment with a dorsal
spine on distal margin.

Telson (Figure 141) with 8 to 10 pairs of inter-
mediate denticles, 26 to 34 submedian denticles.

P()stlar\a (Iigure 2

Measurements (mmi: RL, 0.50 to 0.60: CL,
2.90 to 3.30; TW, 2.55 to 3.10; RVV. 0.65 to 0.75; tL.
1.95 to 2.55: TL, 12.3 to 14.20.

Eyes large, extending to middle of second seg-
ment of antennular peduncle. Cornea bilobed, set

obliquely on stalk. Ocular scales rounded, anterior
margin of opthalmic somite evenly rounded.

Antennular process produced into blunt spine
directed anterolaterally, antennular peduncle
slightly shorter than carapace, antennule ( Figure
25Ai with inner flagellum bearing 34 segments,
median flagellum with 30 segments, outer flagel-
lum with 15 segments and 22 aesthetascs ar-
ranged in eight groups of 2 or 3.

Antenna (Figure 25Bi with 63 to 75 plumose
setae, endopod with 16 segments.

Rostral plate wider than long, lateral margins
tapering to rounded apex. Median carina present.

Anterolateral angle of carapace without spine,
almost forming right angle, posterolateral mar-
gins broadly rounded, carinae poorly developed,
median carina not bifurcate anteriorly or pos-
teriorly, intermediate and lateral carinae present,
reflected carinae absent.

Mandible (Figure 25C) serrate, mandibular
palp absent.

Maxillule (Figure 25D) with coxal endite bear-
ing 26 to 27 strong marginal teeth and 6 to 9 small
medial teeth. Basal endite with one spine flanked

80

MORGAN and PROVENZANO, DEVELOPMENT OF SQUILLA EMPUSA LARVAE AND POSTLARVA

FIGURE 18. Squilla empusa. A-E:
stage VII, first to fifth pleopods re-
spectively.

by one strong seta. Distal margin of basis with
three setae. Endopod present as palp on distal
margin of basis, armed with two setae.

Maxilla (Figure 25E) four-segmented, two prox-
imal segments with endites, second bilobed.

Five pairs of maxillipeds (Figure 25F to 25J)
each maxilliped with one epipod. First maxilliped
(Figure 25F) with distal margin of propodus bear-
ing 14 teeth, inner margin with 48 to 50 strong
setae arranged in 10 transverse rows, 2 or .3 most
distal setae spatulate with strong setules.

Second maxilliped (Figure 25Gi with dactylus
bearing six teeth, pectinate propodus with three
moveable proximal spines, dorsal ridge of carpus
undivided.

Pereiopods (Figure 26A) with setose endopod
and exopod.

Last three thoracic somites with unarmed sub-
median and intermediate carinae. Lateral process
of fifth thoracic somite subacute, sloping pos-

teriorly. Lateral processes of next two somites
bilobed each with a small anterior lobe and a large
broadly rounded posterior lobe. Median ventral
keel of eighth somite with rounded apex.

Abdomen broad, depressed, Submedian, inter-
mediate, lateral, and marginal carinae present.
Abdominal spines in submedian carinae of sixth
somite, intermediate and lateral carinae of fifth
and sixth somites, and marginal carinae of fifth
somite, formula: submedian 6; intermediate 5 to 6;
lateral, 5 to 6; marginal, 5. Sixth abdominal so-
mite with sharp ventral spine anterior to uropod
articulation.

Pleopods (Figure 26B to 26Fl with gills. Pleopod
setation presented in Table 2.

Uropod (Figure 26G) with eight graded move-
able spines on outer margin of proximal segment
of exopod, last extending to middle of apical seg-
ment. Apical segment of exopod extending pos-
teriorly to apex of intermediate spine. Basal seg-

81

FISHERY BULLETIN: VOL 77. NO 1

Table 2. — Number of setae on margins of pleopods of the post-
larva ofSqutlla empusa.

Figure 19- — SquiUa empusa. stage VIII. ventral view.

merit of uropod with dorsal spine on distal margin.
Basal prolongation of uropod with two spines, me-
sial longer. Single rounded lobe between spines of
prolongation. Mesial margin of basal prolongation
sinuate.

Telson (Figure 24) as wide as long, median
carina with sharp posterior spine, prelateral lobes
absent, postanal ventral carina absent, subme-
dian teeth with moveable apices, denticle formula:
submedian, 8 to 10; intermediate, 7 to 10; lateral,
1.

Postlarva white with brown chromatophores on
eyes and all appendages except mouthparts.
Carapace with few chromatophores. Exposed
thoracomeres with chromatophores along pos-
terior margin. Pleomeres with chromatophores
along intermediate and lateral carinae and pos-
terior margin. Telson with chromatophores along
curved dorsal striations and posterior spine.

Abdominal somite

structure

1

2

3

4

5

Protopod
Endopod
Exopod

12-15
55-60
55-59

12-15
60-71
61-64

12-15
66-72
62-64

12-14
63-72
61-63

8-11
59-67
53-56

DISCUSSION

Brooks 11878) and Faxon ( 1882) have produced
the only prior publications on the larvae ofSquilla
empusa. Brooks partially described the develop-
ment by reconstruction, and Faxon held an un-
identified last stage through metamorphosis to at-
tempt to identify it with the adult. .'Although
Brooks* illustrations and descriptions indicate
that he probably was working with S. empu.'^a,
Faxon's do not. The carapace of Faxon's last stage
larvae appears to be too broad, the posterolateral
spines are too short, and a spinule is present on the
posterior margin of the carapace midway between
the dorsal and posterolateral spines. Further-
more, in Faxon's illustrations both the last larval
stage and postlarva have broad abdomens with the
first pleomere being as wide as the sixth, but in .S.
empusa, the abdomen is tapered with smaller an-
terior pleomeres grading into larger posterior
ones.

Faxon collected his larva from Newport, R.I.,
where only four species of stomatopods are known
to reside: S. empusa. Nannnsquilla grayi. Hetern-
squilla arinata. and Platysquilla cnodis (Manning
1974). Because the telson of Faxon's postlarva
bears four intermediate denticles, it can be attrib-
uted to the Squillidae, and S. empusa is the only
squillid known to inhabit the area; the other three
species belong to the Lysiosquillidae. Few larval
descriptions have been made on southern species
of squillid larvae, and of these none possesses the
pair of spines on the posterior margin of the
carapace, seen in Faxon's larva, nor does S. em-
pusa. If Alikunhi (1952, 1967) was con-ect in his
identification of the late larva and postlarva, these
spines occur on Cloridopsis scorpio from the In-
dian Ocean. The spines may be only a specific
character or they may be diagnostic for the genus
Cloriflopsis. The only member of that genus in-
habiting the waters of the Western Atlantic is C
(luhia which ranges from South Carolina to Brazil.
Perhaps Faxon collected a larva of C. duhia which
drifted north with the Gulf Stream. Until more
larval descriptions are worked out for western At-

82

MORGAN and PROVENZANO DEVELOPMENT OF SQUILLA EMPUSA LARVAE AND POSTLARVA

FR;URE 20.— Squilla cmpusa. A-E:
stage VTII, first to fifth pleopods re-
spectively.

lantic species of stomatopods, the identity of Fax-
on's larva will remain uncertain.

To identify larvae of S. empusa the spinules of
the carapace and denticles of the telson should be
examined. Stages I and II possess four spinules on
the lateral margin of the carapace and four inter-
mediate denticles. The third to ninth stages are
armed with six spinules on the lateral margin of

the carapace. There are two anterior and three
posterior spinules all ventrally directed, and one
median spinule laterally directed. The telsons of
stages III to IX have S to 10 mtermediate denti-
cles.

Except for Provenzano and Manning (1978),
who reared Gonadactyius oerstedii from hatching
to metamorphosis, experimenters who have at-

83

FISHERY BULLETIN VOL 77. NO 1

Figure 21. — SquiUa empusa. stage IX, ventral view.

tempted to hatch and rear larvae either to link
them with an adult or to describe the entire larval
development have been unsuccessful at rearing
larvae past the first pelagic stage because the lar-
vae could not be induced to feed (Manning and
Provenzano 1963). Pyne ( 1972) was unable to rear
Pterygosquilla arinata schizodontia eggs past the
first pelagic stage, but did hold stages I to VII
larvae taken from the plankton for periods as long
as 10 to 16 days wherein the larvae passed through
at least one ecdysis. Pyne also found it possible to
keep later stage larvae for very much longer
periods of up to 165 days during which time they
molted as many as six times. Pyne reared his lar-
vae in mass culture using 4-in (10.2-cm) finger

bowls. Alikunhi ( 1975) reared planktonic larvae of
Oratosquilla nepa in aquaria through metamor-
phosis until they reached adulthood, bred, and
produced eggs.

The manner in which all .species of Squillidae
develop is similar. All Squillidae hatch as
pseudozeae with four pairs of pleopods and develop
into the alima form. Some, if not all, pass through
two propelagic stages before the first truly
planktonic stage. The alima is characterized by a
telson with four or more intermediate denticles,
the distance between the submedian spines in
later stages being not larger than that between
the intermediate and submedian spines, the pro-
podus of the second maxilliped bearing three basal
spines, the antennular somite generally having a
median spine, the posterolateral spine of the
carapace having a basal accessory spine, the eye-
stalks long, and the exopod of the uropod being
longer than the endopod (Gurney 1942, 1946).
Alikunhi (1952) added that alima larvae possess
carapaces armed with a varying number of
spinules on the lateral margins, the sixth abdomi-
nal somite usually being equipped with a pair of
submedian dorsal spines, and in advanced larvae,
the posterolateral angles of the abdominal somites
ending in acute or subacute spines.

Alikunhi (1952) noted that between allied
species, the specific differences are often "trivial"
but remarkably constant. He determined that
some features, such as the size of the final pelagic
stage, the shape and spinulation of the carapace,
telson, and uropods.and the presence or absence of
teeth other than the terminal on the dactylus of
the second maxilliped, hardly show any variation
within a species. These characters may be used for
specific determinations but are presently of little
aid in defining generic alliances for three reasons.

First, relatively few stomatopods have been as-
sociated definitely with the adult of the species.

Second, most of these have had described only
one larval .stage of the entire development. Only
19 of the Squillidae have been definitely connected
with their larval forms. Provenzano and Manning
(1978) listed 17 species of identified stomatopod
larvae, but O. masnavensis was omitted and S.
empusa has now been added to the list. Of the 19
species, only 2. P. arinata schizodentia andS. em-
pusa, have been reared in the laboratory through
essentially their entire pelagic development. Two
additional species have been hatched from eggs
obtained from a known adult and the first pelagic
stage described, i.e., Chirida vhoprat by Gurney

84

MORGAN and PROVENZANO DEVELOPMENT OF SQUILLA EMPUSA LARVAE AND POSTLARVA

•"'11 III r^hMk *!i%

FIGURE 22— Squilh empusa. A-C: stage IX, first to third pleopods respectively.

Figure 2Z.—SquiUa empusa. A-B: stage IX, fourth to fifth pleopods respectively; C: stage IX, uropod.

85

FISHERY BULLETIN VOL 77. NO 1

FlOURE 24. — Squilla empiisa. postlarva. dorsal view.

( 1946) andS. mu/ilis by Giesbrecht ( 1910), and the
remainder have had the last stage described by
holding the final pelagic stage until metamor-
phosis occurred and the stomatopod could be corre-
lated with an adult of the species. Reconstructions
of the larval development of three species, .S. man-
tis by Giesbrecht ( 1910), O. oratoriu by Komai and
Tung (1929), and O. maasavensis by Gohar and
Al-Kholy (1957), were attempted by collecting
larval stages from the plankton and piecing them
together. Metamorphosis from the last larval
stage was obtained for O. massavensis, but since
the larvae were not reared, the larval histories
may not be entirely factual. Thus, because so few
larval forms have been identified and because

most of these have had only one stage described, it
is difficult to discover which characters are shared
by all members of a genus and which characters
are only specific. Of the nine genera of Squillidae
which have had larvae described, four genera have
had one or more larval stages of a single species
described, four more genera have had two species
identified, and one genus has had larvae of eight
species described. A determination of generic
characters is difficult at best for those genera for
which only one or two species have been described,
especially since there are no adequately rep-
resented genera with which to compare charac-
ters.

The third reason why specific characters are of
little help in generic definition lies in the incom-
plete descriptions of the larval stages. Characters
noted by one author are frequently omitted by
another, so that even for the genus Oratosquilta,
represented by larval descriptions of eight species,
consistent characters are difficult to recognize.

An assessment of larval characters was at-
tempted to determine which ones were constant
within each genus. Most characters mentioned in
the descriptions appeared to vary a gr-eat deal for
the species within a genus, or the characters that
varied relatively little within a genus were fre-
quently found in other species of different genera.
Of possible value in defining generic associations
is the presence or absence of teeth (other than the
terminal ) on the dactylus of the second maxilliped.
These teeth occur during the last stage in the
genera Anchisquil la , Clorida , Pterygosquilla , and
Squilloides, although for each of these genera lar-
vae of only one species have been described. The
dactylus of P. annata schizodontia is armed with 5
to 8 teeth and the first stage is easily diagnosed by
the posterior spines of the carapace which bear 6 to
16 spirally arranged, proximal spinules. The
spinules are replaced by three ventral spinules in
the remaining stages (Pyne 1972). The dactyl of
the second maxilliped is equipped with two free
teeth in A. fasciata, three teeth inS. lata, and inC.
latreillei is usually armed with one tooth, rarely
with two (Alikunhi 1952). Newly hatched larvae
of C. choprai were too inadequately described to be
compared withC. latreillei (Tweedie 1935; Gurney
19461, but the dactylus of the second maxilliped
was observed to be unarmed. This is not surprising
since C. latreillei and S. lata develop teeth on the
dactylus of the second maxilliped in the later
stages and P. armata schizodontia develops its
first tooth in the third stage.

86

MORGAN and PROVENZANO DEVELOPMENT OF St^CILLA E.VtPL'SA LARVAE AND POSTLARVA

1 A.R F

J 1

1 0mm

1 C-E

1

Figure 25. — Squilla empusa. postlarva. A, antennule; B.
antenna; C, mandible; D. maxillule; E, maxilla; F-J, first to
fifth maxillipeds respectively.

87

FISHERY BULLETIN VOL 77. NO 1

I, ,^.^f?ffe

mm

0mh ilM^.

Figure 26. — Sqmlla cmpusa, postlarva. A, first pereipod; B-F. first to fifth pleopods respec-
tively; G, uropod.

88

MORGAN and PROVENZANO: DEVELOPMENT OF SQL' ILL A KMPl'SA LARVAE AND POSTLARVA

The second maxilliped of the remaining de-
scribed larvae is unarmed throughout the larval
development. To distinguish these genera, other
characters, such as the presence or absence of a
spine on the basis of the second maxilliped, must
be relied on. The spine is definitely born by seven
of the eight species oi OratosquiUa, but was not
mentioned for O. massavensis. Other species,
Squilla enipusa. P. armata schizodontia , Aliina
hyalina, and Meiosquilla lebouri have the spine,
while Harpiosqiiilla harpax and A. fasclata
definitely do not.

The development of epipods on five pairs of
maxillipeds in older larvae appears to be a generic
character of Squilla as most other genera bear four
pairs of epipods.

Characters such as rostral length and spinula-
tion. carapace and telson shape, size, and spinula-
tion, and overall body size and appearance have
been too variable within the limited number of
species presently described to use them in defining
generic associations of the larvae. Deriving
characters which apply to the youngest larvae as
well as the old will be difficult since far fewer
characters are present in the early stage larvae,
and the gross appearance of the young larvae is
very similar due to the small degree of differentia-
tion. Other characters such as antennular seg-
mentation, mouthpart morphology, setation, spi-
nation of the maxillipeds, or the presence of
ocular, antennular, epistomal, or basal uropodal
spines may also need to be examined. The setation
and spination of the first maxilliped may be of
great value in defining alliances of the species as
well as in making specific determinations. How-
ever, many more complete descriptions of the lar-
val developments undergone by the various
species must be accomplished before larval
characters can be used in establishing generic re-
lationships.

The postlarva of Squilla empusa exh-ibited the
basic features of first stage postlarva as deter-
mined for other species by Alikunhi (1967). These
include the absence of anterolateral spines on the
carapace, the extremely poorly developed carina-
tion of the carapace, acutely pointed marginal
denticles of the telson, and moveable apices of the
submedian spines of the telson. As with the adult,
the postlarva possesses the full complement of
teeth on the raptorial dactylus, just as Alikunhi
11967) found. Furthermore, the five pairs of
epipods found in the adult are also possessed by
the postlarva. Other adult characters were de-

veloped upon the next molt. The dorsal carinations
of the carapace were developed, the lateral proces-
ses of the exposed thoracic somites five through
eight resembled those of the adult, the marginal
denticles of the telson were not as acute, and the
submedian spines were fixed. The abdominal spi-
nal formula was still not equal to that of the adult.
Nevertheless, after the postlarva had undergone
its first molt more than enough characters were
shared with the adult to make a definite determi-
nation of the species.

CONCLUSIONS

1. Squilla einpusa undergoes nine pelagic
stages before attaining the postlarval stage.

2. The last stage stomatopod larva and post-
larva described by Faxon (1882) are not S.
t'inpusd.

3. Larvae of .S. cmputia may be identified by the
spinules of the carapace and the inter-
mediate denticles of the telson. Stages I and
II possess four spinules on the lateral margin
of the carapace and four intermediate denti-
cles. The third to ninth stages are armed with
six spinules on the lateral margin of the
carapace. There are two anterior and three
posterior spinules all ventralh' directed, and
one median spinule laterally directed. The
telsons of stages III to I.X have 8 to 10 inter-
mediate denticles.

4. Rostral length and spinulation. carapace and
telson size and spinulation, and overall body
size and appearance probably are specific
rather than generic characters.

5. The presence or absence of teeth on the dac-
tylus of the second maxilliped. the presence
or absence of a spine on the basis of the sec-
ond maxilliped. and the number of epipods
may all be useful characters in determining
generic status of larvae belonging to the
Squillidae. However, many more complete
descriptions of the larval developments un-
dergone by the various species are needed
before larval characters can be used in estab-
lishing generic relationships.

ACKNOWLEDGMENTS

We are indebted to the National Science Found-
ation for its support of this work under grant
DEB76-11716 to the Old Dommion University Re-
search Foundation.

89

FISHERY BULLETIN VOL 77. NO. 1

LITERATURE CITED

Alikl'nhi. k. h.

1952. An account of the stomatopod larvae of the Madras
plankton. Rec. Indian Mus. (Calcutta! 49:239-319.

1967. An account of the post-larval development, moult-
ing, and growth of the common stomatopods of the Madras
coast. In Symposium on Crustacea. Ernakulam, India,
1965, p 824-939. Mar. Biol. Assoc. India, Symp. Ser. 2.

1975. Studies on Indonesian stomatopods 1. Growth,
maturity and spawning of Squilla nepa. Bull. Shrimp
Cult. Res. Cent. 1(11:27-32.
BROOKS. W. K.

1878. The larval stages of Squilla empusa Say. Johns
Hopkins Univ., Chesapeake Zool. Lab. Sci. Res.
1878:143-170.

Burrows. M.

1969. The mechanics and neural control of the prey cap-
ture strike in the mantid shrimps S(//;i //a andHemisquil-
la. Z. vgl, Physiol. 62:361-381.

DRAGOVICH. A.

1970. The food of skipjack and yellowfin tunas m the At-
lantic Ocean. U.S. Fish Wildl. Serv., Fish. Bull. 68:445-
460.

F.WON. W.

1882. I. — Crustacea. In A. Agassiz, W. Faxon, and E. L.
Mark (compilersl. Selections from embryological mono-
graphs. Mem, Mus. Comp. Zool, (Harv. Univ. I 9(li, 14
plates.

Fish. C. J.

1925. Seasonal distribution of the plankton of the Woods
Hole region. Bull. [U.S.I Bur, Fish. 41:91-179.
GIESBRECHT, W.

1910. Stomatopoden. Erster Theil. Fauna Flora Golfes
von Neapel, Monogr. 33, 239 p.
GOH.'^R. H. A. F., .-XNl) A. A. AL-KHOLY

1957. The larval stages of three stomatopod Crustacea
(from the Red Sea). Publ. Mar. Biol. Stn., Al-Ghardaqa
(Red Seal 9:85-130.
GURNEY. R.

1942. Larvae of decapod Crustacea. Ray Soc. (Lond.i

Publ. 129, 306 p.
1946. Notes on stomatopod larvae. Proc. Zool. Soc. Lond.
116(11:133-175.
HlLDEBR.-\ND, H. H.

1954. A study of the fauna of the brown shrimp tPcnacux
aztecus Ives) grounds in the western Gulf of
Mexico. Publ. Inst. Mar. Sci., Univ. Tex. 3:233-366.

Vol. 3, Crustacea. Wiley In-

Kaestner. a.

1970. Invertebrate zoology,
terscience, N.Y., 523 p.

KOMAi. T., AND Y. M. Tung.

1929. Notes on the larval stages of Squilla oratoria, with
remarks on some other stomatopod larvae found in the
Japanese Seas. Annot, Zool. Jpn. 12:187-214.
LEBOUR, M. V.

1924 Young anglers in captivity and some of their
enemies. A study in a plunger jar. J. Mar. Biol. Assoc.
U.K. 13:721-734.

MacGinitie, G. E.. and N. MacGinitie.

1968. Natural history of marine animals, 2d
ed. McGraw-Hill, NY., 523 p.

Manning, R, B,

1969. Stomatopod Crustacea of the western Atlan-
tic, Stud. Trop. Oceanogr. (Miami) 8, 380 p.

1974. Marine flora and fauna of the northeastern United
States. Crustacea: Stomatopoda. U.S. Dep. Commer.,
NOAA Tech. Rep. NMFS CIRC-387, 6 p.

Manning. R. B., and A. J. Provenzano, Jr.

1963. Studies on development of stomatopod Crustacea I.
Early larval stages of Gonodactylus oerstedii Han-
sen. Bull. Mar. Sci. Gulf Caribb. 13:467-487.

PICCINETTI, C, AND G. P. MANFRIN

1970. Prime osservazioni suH'ahmentazione di Squilla
mantis L. Bologna Univ. Inst. Zool. Note 3l 101:251-263.

PROVENZANO, A. J., JR . AND R. B. MANNING

1978. Studies on development of stomatopod Crustacea II.
The later larval stages oi Gonodactylus oerstedii Hansen
reared in the laboratory. Bull. Mar. Sci. 28:297-315.
PYNE, R, R.

1972, Larval development and behaviour of the mantis
shrimp Squilla armnta Milne Edwards (Crustacea:
Stomatopodal. J. R. Soc. N.Z. 2:121-146.

Randall, J, E.

1967. Food habitsof reef fishes of the West Indies. Stud.
Trop. Oceanogr. (Miami) 5:665-847,
RKINT.JES. J. W., AND J, E. KING.

1953. Food of yellowfin tuna in the central Pacific. U.S.
Fish Wildl. Serv., Fish. Bull. 54:91-110.
SUNIER. A.

1917. The Stomatopoda of the collection "Visscherijsta-
tion" at Batavia. Contrib. Faune Indes Neerl. 1(4):62-
75.
TWEEDIE. M. W. F.

1935. Two new species of Squilla from Malayan waters.
Bull. Raffles Mus. 10:45-52.

90

VARIATION IN THE FOURBEARD ROCKLING,

ENCHELYOPUS CIMBRIUS, A NORTH ATLANTIC GADID FISH,

WITH COMMENTS ON THE GENERA OF ROCKLINGS

Daniel M. Cohen' and Joseph L. Russo^

ABSTRACT

Enchelyopus cimbriun, the fourbeard rockling, is a gadid fish living around the rim of the North
Atlantic Ocean. It varies geographically in color pattern; anal, dorsal, and pectoral fin ray counts; and
vertebral and gill racker counts. There is a lack of overall concordance in patternsof vanation in color
and meristics. Morphometric characters do not distinguish populations from different geographical
areas, and the fourbeard rockling is considered to be a single species.

New distributional records include the Gulf of Mexico, West Greenland, and West Africa.

We classify the rockiings as a tribe, Gaidropsanni, of the subfamily Lotinae. Characters previously
used to separate rockiings into five genera — skull shape, vomerine tooth patch shape, number and
distribution of supratemporal pores, length of first dorsal fin ray, and size of jaw teeth — do not
distinguish nominal genera. Number of snout barbels divides rockiings into three groups that we
tentatively recognize as genera: Gaidropsarus. the threebeard rockiings, with two snout barbels;
Enchelyopus, the fourbeard rockling. with three snout barbels; and Ciliata, the fivebeard rockiings.
with four or more snout barbels. Onogadus and Antonogadus are referred to the synonymy of Gaidrop-
sarus.

The correct generic name for the fourbeard rockling isEnckelyopus Bloch and Schneider 1801 , with
Rhinonemus Gill 1863 as a junior synonym. It is not preempted by Enchelyopus Gronovius 1760 in
Zoarcidae. which was used in a work that was not consistently binominal.

The fourbeard rockling, Enchelyopus cimbritis, is
a locally abundant gadid fish found around the
margins of the North Atlantic Ocean. Although
this fish has been recorded in the literature for
more than 200 yr, many aspects of its biology are
obscure. Adults are sedentary bottom dwellers
taken at depths ranging from about 1 to 650 m [we
have been unable to verify depth records to 1,325
m given by Goode and Bean ( 1896) ]. There is some
indication that seasonal offshore-onshore move-
ments occur (Bigelow and Schroeder 1953; Tyler
1971). The pelagic larval stages are similar in
appearance to young hakes ( Urophycis ) and some-
times occur in silvery swarms near the surface
(Bigelow and Schroeder 1953).

Recent collections discussed in this paper show
that fourbeard rockiings are more widely distrib-
uted than previously was known and that geo-
graphical variation is present. One of our objec-
tives in this paper is to describe, compare, and

'Systematics Laboratory. National Marine Fisheries Service,
National Museum of Natural History, Washington, DC 20560.

^Systematics Laboratory, National Marine Fisheries Service,
National Museum of Natural History, Washington, DC; pres-
ent address: Department of Biological Sciences, The George
Washington University, Washington, DC 20006.

Manuscript accepted August 1978
FISHERY BULLETIN VOL 77. NO 1, IHTH

evaluate geographical variation of selected
characters and to show that a single species is
represented throughout the range of the fish.

The rockling group of the family Gadidae, which
is characterized by several distinctive features,
recently was divided into five genera (Wheeler
1969), although most ichthyologists have recog-
nized only three (albeit under a variety of names).
The second of our objectives is to show that at
present there are valid reasons for only three.

The fourbeard rockling is currently named En-
chelyopus cimbrius by North American
ichthyologists and Rinonemus cimbrius by Euro-
peans. Our final objective is to show that En-
chelyopus is the correct generic name.

METHODS

All observations were made on museum speci-
mens listed in the Appendix. Counts of dorsal and
anal fin rays and vertebrae were taken from X-ray
photographs. Vertebral counts do not include the
terminal ural element. Gill raker counts include
all rakers on upper and lower arms of the first
arch. Head pores were examined with the aid of a
compressed air jet. Measurements and their

91

FISHERY BULLETIN VOL 77. NO 1

statistical analysis are described under Body
Proportions. Statistical tests were performed on
the IBM :i70-148' computer at The George
Washington University, using computer pro-
grams written and maintained at the Systematics
Laboratory, NMFS, NOAA. and following .statis-
tical methods presented by Zar (1974).

GEOGRAPHICAL VARIATION

The distribution of the fourbeard rockling may
be summarized as the coastal waters of the North
Atlantic. In the western Atlantic the species oc-
curs in: West Greenland (new record); the north-
western Gulf of Saint Lawrence and around New-
foundland as well (Leim and Scott 1966 and this
paper) to Cape Fear (about lat. 34°N) ( Bigelow and
Schroeder 1953); the northeast coast of Florida
(Bullis and Thompson 1965); off the Florida Keys
(new record); and in the northern Gulf of Mexico
(new record). In the eastern Atlantic the species
occurs: around Iceland (Saemundsson 1949) and
the Faroes (Joensen and Taaning 1970); from
northern Norway at about lat. 71°N in the Barents
Sea and south along the coasts of Scandinavia
(Andriyashev 1954); in the western Baltic (rarely
to the Gulf of Finland, Svetovidov 1973); th rough -

^Reference to trade names does not imply endorsement by the
National Marine Fisheries Service, NOAA.

out the Noi'th Sea and around the British Isles to
the northern Bay of Biscay (Wheeler 1969; Du
Buit 1968); and off Cape Blanc, Mauritania (new
record). It is not known from the Mediterranean.
Figure 1 shows the approximate localities from
which we have studied specimens. More detailed
locality data are presented in the Appendix.

Sampling Areas

We have compared fish from the following geo-
graphical areas.

Gulf of Mexico. Only 3 localities are represented
in our collections. These specimens are among the
most darkly pigmented of any we have studied.

Southern Atlantic. Specimens taken from the
South Carolina coast at about lat. 33°N to about
lat. 29^N on the east coast of Florida, which is as
far south as specimens have been caught in the
western Atlantic outside of the Gulf of Mexico.
There is no reason to doubt that this population is
continuous with those farther north, and the
northern boundary as here given is arbitrarily
limited by available study material.

Intermediate. Fish caught in the vicinity of Cape
Hatteras from about lat. 35°N to the vicinity of
Norfolk Canyon at about lat. 37"N are included in

Figure l. — Localities for our specimens of Efichelyopus cimbriu^. Some dots represent more than one collection. For detailed data on

localities see Appendix.

92

COHEN and RUSSO: VARUTION IN FOURBEARD ROCKLING

this area, which we separate because it is geo-
graphically between the region to the south.
where fishes are mostly dark colored.

Northern Atlantic. This region extends along
the western Atlantic coast from north of the vicin-
ity of Norfolk Canyon to the northern North
American limit of E. cimbrius occurrence.

Greenland. A single specimen from West Green-
land is apparently the only known occurrence of £.
cimbrius from Greenland.

Iceland. The region around Iceland.

Europe. Although E. cimbrius occupies a con-
siderable area we have examined only a small
sample, mainly from Denmark and Norway.

Africa. Two specimens from off the coast of
Mauritania ca. lat. 21°N are the most southerly
known.

Color

Enchvlyopus cimbrius from the Gulf of Mexico
and Southern Atlantic areas have on the average
more of the dorsal fin colored with dark pigment
than do fourbeard rocklings from other areas (Ta-
ble 1 ). We have attempted to quantify this charac-
ter by coding it on a 0-10 scale with representing

Table l. — Frequency distributions of degree of dorsal fin pig-
mentation in Enchelyopus cimbrius from eight geographical
areas. = no dark pigment in dorsal fin; 10 = entire fin darkly
pigmented.

Degree of

pigmenta

ion

N

Area

1

2 3

4

5 6 7

8

9

10

X SD

Gull ol Mexico

2

1

5 2 4

1

1

2

18

62 2 1

Southefn Atlantic

1

- 2

6

1 6 17

6

6

2

47

67 19

Intermediate

7

6 4

6

2

1

3

1

30

3 6 2 8

Northern Atlantic

29

5 7

3

— 2

46

18 13

Greenland

1

1

5 -

Iceland

5

2 2

1

■*

10

19 11

Europe

1 26

1 1

1

2

32

14 09

Afnca

1

1

2

1 5 —

a fin with no dark pigment and 10 representing a
fin that is completely dark. Values were subjec-
tively assigned by a single observer (Cohen). Fig-
ure 2A shows a New England fish that would be
coded as 1; Figure 2B shows the color pattern of a
fish from the Gulf of Mexico, which would be coded
as 6. Note that fish are morphologically inter-
mediate and most variable in the Intermediate
region'* where the mean is 3.8 and the standard
deviation is highest at 2.8.

Two other pigment characters were noted; how-
ever, neither was quantified. Fish with light fins
lacked dark pigment in the groove along the base
of the row of filaments between the strong first
dorsal ray and the beginning of the normally de-
veloped dorsal fin ( Figure 3 A); fish with dark dor-
sal fins had varying amounts of dark pigment in
this region (Figure 3B). Also, in many Gulf,
Southern Atlantic, and Intermediate fish the body
was dusky; in most others the body was a rather
light straw color.

Meristics

Frequencies of both anal fin rays and dorsal fin
rays show a pattern similar to, though less pro-
nounced than, that shown by dorsal fin pigmenta-
tion in the western Atlantic (Tables 2, 3), with fish
from the Intermediate area being intermediate
between fish from the north and the south. Also,
for anal fin rays the standard deviation is larger in
fish from the Intermediate area than in adjacent
samples. These two characters differ from dorsal
pigmentation in having the highest mean in the
Iceland sample.

Frequencies of pectoral fin rays and vertebrae
for North American samples from the Inter-
mediate area have nearly identical means in both

■'Detailed descriptions of color variation in samples from Nor-
folk Canyon and comparisons with specimens from the northeast
coast of Florida have been presented by: P, Szarek. 1974 A
preliminary study of Norfolk Canyon Enchelyopus cimbrius.
Ichthyology Term Paper. Virginia Institute of Marine Science.

Table 2. — Frequency distributionsof numbers of anal fin rays in Enchelyopus cimbrius from

eight geographical areas.

Number of anal fin rays

N

X

Area

36

37

38

39

40 41

42

43

44

45

46

47 48

49

SO

Gulf of Mexico

6

4 2

4

16

40 2

1 2

Southern Atlantic

6

1 1 18

8

3

46

40 8

1 1

Intermediate

1

2 5

4

7

2

2

2

— —

1

26

42 8

22

Northern Atlantic

8

8

9

13

9

2

2 1

52

43 5

1 7

Greenland

1

1

43

—

Iceland

2

4

3

1

10

453

09

Europe

1

—

1

1

— 2

1

3

6

1

—

— —

1

17

426

30

Afnca

1

1

2

44 5

—

93

FISHERY BULLETIN; VOL, 77. NO. 1

FIGURE2.—£nc/n>/yDpu.s(imfcriu.s. A, USNM 213501. standard length 282 mm, offCape Cod, dorsal fin pattern coded as 1 (see text). B,
color pattern of a fish from the Gulf of Mexico (USNM 2 1 784.3 1 drawn on the outline of the fish shown in Figure 2 A, dorsal fin pattern
coded as 6 (see text).

Table 3. — Frequency distributions of numbers of dorsal fin rays in Emhelyapus
ctmbnus from eight geographical areas.

Number of dorsal fi

n rays

N

X

Area

45

46

47 48

49

50

51

52

53

54

55

SO

Guit ol Mexico

1

1

11 3

16

47

07

Southern Atlantic

1

8

10 12

7

8

1

47

4/9

15

Intermediate

1 3

8

9

5

—

2

1

29

49 9

1 6

Northern Atlantic

1

—

- 6

13

8

12

4

4

3

1

52

50 4

1 y

Greenland

1

1

51

—

Iceland

5

2

3

10

50 8

09

Europe

1

2 3

3

4

3

1

17

49 2

1 7

Africa

2

2

50,0

—

of these characters with Northern Atlantic fish,
rather than being intermediate (Tables 4, 5); how-
ever, for pectoral fin rays, fish from these two areas
have lower counts that are in between Gulf and
Alantic, and Greenland, Iceland, and Europe
samples. Iceland fish average highest of all in dor-
sal and anal fin ray counts and in vertebral counts
(not including the few specimens from Greenland
and Africa). In pectoral counts, however, Iceland
and Europe specimens have identical means.

In total gill raker counts (Table 6) eastern At-
lantic samples have higher means than do western

Atlantic samples, with the highest standard de-
viation being in the Northern Atlantic samples.

Body Proportions

Measurements were taken of the following eight
body parts and compared for six of them in fish
from the six geogi-aphical areas listed below and
described previously under sampling areas
(Greenland and Africa are not included in the
present analysis). Linear regressions were calcu-
lated for the following dependent variables, with
standard length as the independent variable:

94

COHEN and RUSSO: VARIATION IN FOURBEARD ROCKLING

Table 5. — Frequency distributions of numbers of pectoral fin
rays in Enchelyopus cimbrius from eight geographical areas.

FIGURE 3— Enchelyopus cimbrius. A. USNM 213501, head
length 62.8 mm, off Cape Cod, note absence of dark pigment
along base of fin with short rays. B, USNM 217843. head length
33.2 mm, Gulf of Mexico, note dark pigment along base of fin
with short ravs.

Table 4, — Frequency distributions of numbers of vertebrae in
Enchelyopus ctmbnus from eight geographical areas.

Number of v

'ertebrae

N

X

Area

49 50

5t

52

53

54

55

SD

Gulf of Mexico

9

7

16

51 4

05

Soutfiem Atlantic

1 1

18

22

10

52

51 8

09

Intermediate

4

7

12

6

1

30

52 8

1

Northern Atlantic

3

14

26

15

1

59

52 9

09

Greenland

1

1

54

—

Iceland

4

3

3

10

53 9

09

Europe

2

3

7

3

15

52 7

1,0

Africa

1

1

2

545

—

Number of

pectoral fin

rays

Area

15

16

17

18

19

N

X

SD

Gull of Mexico

1

2

9

6

1

19

17.2

0.9

Southern Atlantic

9

21

14

1

45

172

08

Intermediate

2

9

14

4

29

167

08

Northern Atlantic

5

21

21

5

1

53

165

09

Greenland

1

1

17

—

Iceland

1

2

2

5

10

17 1

1 1

Europe

1

2

8

4

1

16

17 1

10

Afnca

2

2

16

—

Table 6. — Frequency distributions of total numbers of gill rak-
ers on first arch in Enchelyopus ctrnhrtus from eight geographi-
cal areas.

Number

of g

ill rakers

Area

5

6 7

8

9

10

11

12

13

N X SD

Gulf of Mexico

5

3

2

—

1

11 90 13

Southern Atlantic

2

9

12

17

4

44 9 3 1,0

Intermediate

1

1

11

6

5

24 9 5 1.0

Northern Atlantic

3

1 1

8

8

12

6

2

41 9 1 18

Greenland

1

1 9 —

Iceland

2

5

2

1

10 10.209

Europe

6

4

3

1

1

15 10,1 1.3

Africa

1

—

1

2 10.0 —

tic 53 (50.5-297); Iceland 10 (151-327); Europe 27
(93.8-300).

Analysis of covariance was used to compare re-
gression lines (Tables 7, 8) for six measurements
that we have treated as linear based on a
coefficient of determination ir^) of 0.73 or higher
(Table 8). Two measurements, ventral fin length
and barbel length, had coefficients of determina-
tion ranging from 0.42 to 0.61 and were not further
analyzed.

Fishes from all si.x geographical areas demon-
strated overall coincidence at the 0.05 level of sig-
nificance in two characters, head length and upper
jaw length. Hypotheses concerning overall coinci-
dence of regressions for the other characters were
rejected and hypotheses concerning the equality of
slopes and intercepts were simultaneously tested.

The hypothesis concerning the equality of slopes
was rejected for the Dj-Dj distance versus stan-
dard length regression lines. Regression data were

snout to first dorsal fin (pre D, distance); first dor-
sal fin to the dorsal fin beginning posterior to the
row of small filamentous rays (D,-D:i distance);
head length; pectoral fin length; upper jaw length;
horizontal diameter of eye (orbit length); length of
barbel on lower jaw; and ventral fin length. Num-
bers of specimens measured and their size ranges
(standard length in millimeters) were: Gulf of
Mexico 17 (125-228); Southern Atlantic 46 (125-
263); Intermediate 29 1 104-202); Northern Atlan-

TABLE 7. — Significance of differences in six morphometric
characters in Enchelyopus cimhrius from six geographical re-
gions. Independent variable is standard length.

Overall

Equality

Equality

Dependent variable

N

coincidence

ol slopes

of intercepts

Pre Di distance

165

'0 0048

5342

"49 10 *

D,-D3 distance

165

'00024

'00111

'0 0012

Head length

182

03004

—

—

Pectoral fin length

150

'00061

0617

'0 0011

Orbit lengh

166

'22 10 '

0.1839

"2 4 10 '

Jaw length

166

2892

—

—

'Rejection of hypothesis of equality at the 05 level of significance
'Reiection of hypothesis of equality at the 001 level of significance

95

FISHERY BULLETIN: VOL.

Table 8. — Y intercepts in millimeters, slopes, coefficients of determination ir^).
and N for regression lines calculated on Enchelyopus cimbnus from six geographi-
cal areas. Independent variable is standard length.

Measurement

Geographical

PreD,

D,-Dj

Head

Pectoral

Upper jaw

Orbit

area

distance

distance

length

fin length

length

length

Gulf of f^lexico:

V intercept

2 91

2 21

2 29

17

-3 08

10

Slope

16

12

18

14

11

04

r'

89

86

93

87

87

79

N

16

16

17

14

17

17

Soutfiern Atlantic:

Y intercept

Oil

■4 74

22

-0 89

-1 83

76

Slope

17

015

20

15

11

04

r'

96

89

94

091

89

090

N

43

44

46

43

44

44

intermediate

Y intercept

■0,60

-0 74

■0 71

48

■2 69

-0 06

Slope

18

12

021

14

11

005

/■'

95

86

92

87

92

79

W

29

29

29

29

29

28

Northern Atlantic.

Y intercept

•0,32

47

■0 43

-2 22

■3 38

1 64

Slope

18

12

21

16

12

004

1-2

0,97

89

97

92

87

92

N

51

51

53

38

51

50

Iceland:

Y intercept

0,47

3 59

2 09

6 02

■5 71

2 65

Slope

0,17

10

20

12

13

03

r'

79

92

99

87

98

98

N

10

10

10

10

9

10

Europe:

Y intercept

-061

■4 37

■0 74

■2 06

■4,70

1,29

Slope

18

16

21

15

12

04

I-'

097

73

91

0,90

91

94

N

16

16

27

16

16

17

submitted to a Newman-Keuls multiple range test
in order to determine which population sample or
groups of population samples were different from
others. This procedure failed to detect differences
between any slopes, a not uncommon occurrence
due to the fact that the analysis of covariance is a
more powerful test than is the multiple range test.
The sample from Iceland had the lowest slope at
0.10, the Northern Atlantic, Gulf of Mexico, and
Intermediate samples each had a slope of 0.12, the
Southern Atlantic sample had a slope of 0.15, and
the sample from Europe had a slope of 0.16.

The hypotheses concerning the equality of Y
intercepts was rejected at the 0.0.5 level of sig-
nificance for all four characters tested. These re-
gression data also were submitted to a Newman-
Keuls multiple range test in order to determine
which population sample or groups of population
samples were different from others. Again, this
procedure failed to detect significant differences
between any Y intercepts.

If a more stringent 0.001 level of significance is
used, only orbit length tests as being significantly
different with respect to overall coincidence. Data
for this regression from each of the six samples
were submitted to a continuation of analysis of
covariance to determine whether differences in

the regression lines were attributable to the slopes
and/or the Y intercepts. We accept equality of the
slopes with a probability of 0.85. However we re-
ject the equality of the Y intercepts after calculat-
ing a probability of equality of 2.06 x 10"''. Re-
gression data were submitted to a Newman-Keuls
test, which failed to detect differences between
any pairs of intercepts. Inspection of our data
shows that rocklings from Iceland appear to have a
proportionally larger eye than do other rocklings;
however, our sample is small and may be biased by
larger fishes; hence we do not draw inferences
from this apparent difference.

Although differences between samples appar-
ently exist, we do not interpret them as represent-
ing the kind of discontinuity that indicates dis-
tinct species. Their significance is beyond the
scope of this paper.

Discussion

We believe that the fourbeard cockling is best
considered as a single species throughout its en-
tire range. Differences in pigment pattern, meris-
tics, and the relative size of several body parts do
exist; however, there are neither trenchant dis-
continuities in variation nor is there any overall

96

COHEN and RVSSO VARIATION IN FOL'RBEARD ROCKLING

concordance in patterns of variation. Differences
between and similarities among samples are
summarized in Figure 4 and discussed below for
meristics and color pattern. Differences in morph-
ometric characters are so slight that we do not
further consider them.

Gulf of Mexico and Southern Atlantic samples
are quite similar, although at this time the two
might be semi-isolated from each other. The
clockwise loop current system in the Gulf of
Mexico provides a possible pathway for the disper-
sal of young, pelagic stage rocklings out of the gulf;
there is no present avenue for recruitment into the
Gulf of Mexico. If the single rockling taken off the
Florida Keys represents more than a stray, then
perhaps Gulf of Mexico and Southern Atlantic
populations are continuous; otherwise, the north
Gulf-northeast Florida distribution pattern is
similar to that noted first in fishes by Ginsburg
(19521. Although E. cimhnus seems rare in the
Gulf of Mexico its occurrence at two widely sepa-
rated localities, with a collection of 16 individuals
from one of them, indicates that the .species is estab-
lished there. Although pelagic stages have not yet
been taken from the Gulf of Mexico or Southern
Atlantic areas, it seems reasonable to assume that
they occur there and are available for dispersal in
the Gulf Stream system.

Rocklings from the Intermediate area are in-
deed intermediate between adjacent populations
to the north and south in degree of pigmentation

and in dorsal and anal ray counts. Furthermore,
for two of these characters, color and number of
anal fin rays, the standard deviation is larger than
in other populations, implying that recruits from
different spawning populations are entering the
area or that the characters are genetic and variabil-
ity is being maintained during spawning in the
Intermediate area. For two characters, numbers of
vertebrae and pectoral fin rays. Intermediate and
Northern Atlantic fish are nearly identical and
differ from Southern Atlantic and Iceland sam-
ples. These characters must be determined or
mediated differently than are color pattern and
dorsal and anal fin ray counts. Gill raker count
appears to reflect still a third method of character
determination as the means are different on the
two sides of the Atlantic. Although pelagic early
stages have not been taken in the Intermediate
area, they may be available for dispersal to the
northeast by means of the Gulf Stream and to the
southwest in coastal currents that parallel the
Gulf Stream. Such dispersal patterns would help
to account for the occurrence of dark-colored rock-
lings in the north and light-colored ones in the
south.

Rocklings from the Northern Atlantic area
more closely resemble fish from Europe and Ice-
land in degree of pigmentation and number of
vertebrae than they do their immediate neighbors
to the south. Conversely they are closer to other
North American samples in numbers of pectoral

CHARACTER

Gulf

S. Atl.

GEOGRAPHICAL AREA

Intermed .

N. Atl.

Iceland

Europe

Color
Anal Rays
Dorsal Rays
Vertebrae
Pectoral Rays
Gill Rakers

6.2

40.2

47.0

51.4

17.2

6. 7

40.8

47.9

51.!

17.2

3.8

42.8

43.5

49.9

50.4

52.8

52.9

16.7

16.S

1.9

1.)

42.6

49.2

FIGL'RE 4. — Summary of means of character states for Enchelyopu^ cimbnus from six geographical areas. Heavy lines are drawn
around entries that are discussed in the te.xt as separate entries and that illustrate overall lack of convergence m character states.

97

FISHERY BULLETIN; VOL, 77. NO, 1

rays and gill rakers. Spawning is known to occur
in the Northern Atlantic area. Eggs have been
taken from surface tows in Passamaquoddy Bay,
where spawning peaked at bottom temperatures
of 9° to 10°C (Battle 1930). In Long Island Sound
eggs were found to be most abundant in the upper
12 m (Williams 1968). In reviewing the natural
history of E. cirnbriuK in the Gulf of Maine,
Bigelow and Schroeder (1953) mentioned the pos-
sibility of planktonic existence as long as 3 mo.
Given such a time span, the complex hydrographic
regime of the area might occasionally distribute
early stages to the south inshore of the Gulf
Stream or even more rarely might transport them
via the Gulf Stream to the eastern Atlantic.

Iceland rocklings are usually light colored, as
are fish from the Northern Atlantic and Europe
areas. For counts of dorsal and anal fin rays, and
vertebrae, Iceland fish have the highest means of
all (ignoring the two fish from Africa); perhaps
these characters are influenced by temperature, as
Iceland has the lowest temperatures of any of the
six areas. In numbers of pectoral rays, Iceland and
European fish are identical and in gill rakers
nearly so, and different from counts of North
American ones. Adults at least of the Iceland
population may be isolated as Kotthaus and Krefft
(1967) did not catch E. cinibritis along the
Iceland-Faroe ridge. Enchelyopus cinihrius
spawns at least around the southwest coast of Ice-
land (Einarsson and Williams 1968).

The linear range of the fourbeard rocklingalong
the coasts of Europe is about as great as along the
coasts of North America. We have examined only a
small sample, from southern Scandinavia; hence,
it is possible that more variation exists than we
have recorded. However, we point out that in our
sample the color pattern resembles that of Iceland
and Northern Atlantic fish, that counts of anal and
dorsal fin rays and vertebrae are lower than those
in Iceland, and that in numbers of pectoral fin rays
and gill rakers Europe and Iceland fish are more
like each other than they are like North American
populations. Rocklings are known to spawn in
European waters [Svetovidov 1 1973) gives several
references]. Enchelyopus cimbrius could have
reached Europe from the west via the Gulf Stream
system; it seems unlikely that east to west disper-
sal is possible.

We do not know whether the West Greenland
specimen of E. cimbrius represents a breeding
population or a stray.

The two West African examples are so far re-

98

moved from their nearest known neighbors ( Bay of
Biscay ) that we forego conjecture as to their origin.

THE GENERA OF ROCKLINGS

The rocklings are classified in the subfamily
Lotinae of the family Gadidae (Svetovidov 1948)
and can be distinguished by the nature of the three
dorsal fins, which, although scarcely separated
from each other, bear quite different kinds of rays
(Figure .5). The first dorsal fin consists of a single,
unsegmented ray which is not bilaterally divided
(we have examined microscopic sections) and is
supported by a strong pterygiophore. The ray is
thicker than any others in the dorsal fin and in
many species is longer as well. In Enchelyopus
cimbrius it is soft, being ossified only proximally.
Sharply distinguished from the first and third dor-
sal fins is a row of small, unsegmented, bilaterally
divided filaments which appear fleshy, although
they stain with alizarin. These small rays origi-
nate on a compressed ridge that rises from a mid-
dorsal groove. Although Bogoljubsky (1908) fol-
lowed by Svetovidov ( 1948) did not consider these
filaments to be true fin rays they should be consi-
dered as such, as examination of an alizarin prep-
aration and of sections shows that a simple, os-
sified, rod-shaped skeletal support is present for
each. The third dorsal fin is composed of ordinary,
bilaterally divided, segmented rays, each with a
well-developed pterygiophore.

A second characteristic of the rocklings is the
presence on the snout of prominent barbels ithe
closest approach to this character among other
gadids being a nasal cirrus in Lota ) in addition to
the barbel at the tip of the lower jaw.

Thus, the rocklings are distinguished by two
specialized characters and can be considered as a
distinct tribe of Lotinae, the Gaidropsarini [clas-
sified as a distinct family by some, for example, de
Buen (1934)].

Although rocklings have been treated under as
many as 14 different generic names [see
Svetovidov (1973) for synonyms], many
ichthyologists (for example, Andriyashev 1954;
Norman 1966) follow Svetovidov (1948) in recog-
nizing three. More recently, however, five genera
have been recognized (Wheeler 1969). How many
genera should be recognized and why?

In his 1948 treatment of the rocklings,
Svetovidov provided diagnoses for the three gen-
era that he recognized based on barbel number,
skull shape, vomerine tooth patch shape, and

COHEN and RUSSO VARIATION IN FOURBEARD ROCKLING

'muiidiiiiiiilM'-

r//

Fl( ;L'RE 5, — Enchelyopus cimhrius. USNM 217900, standard length 135 mm; photograph of an alizarm preparation m glycerin showing
the three different kinds of dorsal fin rays and their skeletal supports.

number and distribution of supratemporal pores
(our Table 9). Unfortunately, he was unable to
study all of the species. We have examined six of
the nominal Gaidropsarus species that he recog-
nized, both species oiCiliata, and, of course, En-
vhelyopus (study material of all genera is listed in
the Appendix).

Number of barbels is the only character that
unequivocally divides our material according to
Svetovidov's classification.

Proper evaluation of the skull-width character
will require the examination of osteological prep-
arations, which we have not done. We note, how-
ever, that although Ciliata inustela has a notably
broad skull, that ofC septentrionalis appears to be
narrower. Also, although most species oiGaidrop-
Hcinis appear to have narrow skulls, that of G.
guttatus appears broad.

Regarding the size and shape of the vomerine
tooth patch, it is highly variable, and although it
may serve to distinguish some species it is of
doubtful value at the genus level.

Table 9. — Summary of diagnostic characters for three rockling
genera given by Svetovidov (1948).

Characters

Genus and no.

No. of

Skull

Supratemporal

of species

barbels

shape

Vomer

pores

Gaidropsarus

3

Narrow

Head large.

3 - 1 pair + 1

(13)

apex angular

median

Enchelyopus

4

Narrow

Small

3 - 1 pair + 1

(1)

median

Ciliata

5 or

Broad

Head small,

2 - 1 pair

(2)

more

anterior a
semicircle

Number of supratemporal pores also is a vari-
able character. Five of the Gaidropsarus species
that we have studied show the pattern given for
the genus by Svetovidov (1948), one median and
one pair of pores ( = 3). However, G. argentatus has
two pairs and no median pores ( = 4). In Ciliata, C.
mustela has one pair ( = 2), while C . septentrionalis
has three pairs ( = 6).

As noted above, Wheeler ( 1969) recognized five
genera, the three recognized by Svetovidov (1948):
Enchelyopus. CUiata. and Gaidropsarus: and also
Onogadus de Buen 19.34; and a genus introduced
for the first time, Antonogadus.

Onogadus was originally proposed for Gaidrop-
sarus ensis, one of the threebeard rocklings, be-
cause of its elongate first dorsal ray. Wheeler (in
Svetovidov 1973) has subsequently assigned to
Onogadus, G. argentatus, a species with a far
shorter first dorsal fin ray. We have found the
length of the first dorsal fin to be highly variable in
Enchelyopus. As presently used, this character
does not separate genera. (Wheeler^ has informed
us that Onogadus may be differentiated on the
basis of vertebral counts. Due to insufficient data
we have no comment on this character.) As we
have mentioned above, G. argentatus differs from
G. ensis and resembles Ciliata in lacking a median
supratemporal pore.

'A. Wheeler. Department of Zoology. British Museum
(Natural History), Cromwell Road, London S.W. 7. England.
Pers. Commun. March 1978.

99

FISHERY BULLETIN VOL 77, NO 1

Antonogadus Wheeler 1969 was first introduced
in the combination Anionngaclus macrophthal-
mus (Giinther), unfortunately, in a key to species
rather than a treatment of genera. Subsequently,
another threebeard rockling, Gaidropsarus
megalokynodon (Kolombatovic 18941, was refer-
red to Antonogadus (Wheeler in Svetovidov 1973)
in a checklist. There is no way to tell if the original
key characters describing dentition, mouth size,
and color are diagnostic of the genus Antonogadus
or the species A. macropththalnius; however, we
assume that they apply to the genus. Color may be
discounted as a generic character as it is highly
variable among the species of Gakhvpsarus and
varies geographically in the single species of En-
chelyopus. Regarding mouth size, Wheeler (1969)
noted "mouth large, extending well past eye":
however, figures of macrophthalnius given by
Gunther [1867, pi. 5, fig. B and 1887, pi. 42, fig. D.
the latter as Onus carpenteri, a junior synonym of
mac!-ophthalmus according to Wheeler in
Svetovidov (1973)] show fish with small mouths.
The second species referred to Antonogadus.
megalokynodon, is figured by Soljan ( 1963) as hav-
ing a large and capacious mouth, but he shows the
same condition for several other species of
threebeard rocklings. So far as we can tell mouth
size is not a useful generic character. Carrying on
to dentition, Wheeler (1969) noted, "A pair of
large, fang-like, teeth (sometimes three or four) in
front of the upper jaw." If Antonogadus is recog-
nized on the basis of such a character then it would
be necessary to place the two species of Ciliata in
separate genera, as C. mustela, the type-species of
the genus has bands of equal-sized teeth in the
upper and lower jaws, while C. septcntrionalis has
in addition to these bands a much enlarged outer
row of teeth in the upper jaw and an enlarged
inner row in the lower jaw.

It is by no means clear that number of barbels
alone divides the rocklings into natural species
assemblages; convergence may have occurred and
other groupings based on different characters may
produce a phyletically more correct classification.
Obviously, thorough study and a careful analysis
of characters is required. For the present there
seems insufficient information available to do
other than recognize on the basis of number of
barbels a single genus with three subgenera, or
three genera. We follow the latter course as it is
the most conservative in terms of the present
usage of names. We recommend therefore, that for
the present Onogadus be relegated once again to

the synonymy of Gaidropsarus where it should be
joined by Antonogadus.

THE CORRECT GENERIC NAME FOR
THE FOURBEARD ROCKLING

Although differences at the species level have
not evolved in populations of the fourbeard rock-
ling on both sides of the North Atlantic, curiously
enough geographical isolation seems to have af-
fected the evolution of different generic names.
Rhinoncinus is used by European ichthyologists
(see, fore.xample, Svetovidov 1973); North Ameri-
can ichthyologists use Enrhelyopus (see, for
example, Leim and Scott 1966). Which is the cor-
rect name?

Enchelyopus Gronovius 1760 was the first of the
two names proposed. Although only a brief color
description was given, reference was made to the
same author's pre-Linnean Museum Ichthyo-
logicum published in 1754, in which work
under the names Mustela vivipera and viviparous
eelpout is presented a recognizable description of
the species presently named Zoanvs viviparus
(Linnaeus). This identification is further verified
by a Gronovius specimen still extant in the British
Museum, which Wheeler ( 1958) has suggested is a
type-specimen of Blennius viviparus Linnaeus.
Use of Enchelyopus in Zoarcidae, where it is a
senior synonym of Zoarces Cuvier 1829 has
been accepted by Norman (1966) and noted as
being correct by Andriyashev (1973). Some
ichthyologists (Gill 1863b;Jordan 1917), however,
seem to have overlooked Gronovius ( 1760) and at-
tributed the name to Gronovius (1763) in his
Zoophylaceum, a work subsequently ruled on by
the International Commission on Zoological
Nomenclature (Opinion 89) as being unavailable
for purposes of zoological nomenclature. The
Commission noted in its ruling that combinations
used in the Zoophylaceum were "binary" though
not "binomial," which interpretation complied
with the then current edition of the Rules, and the
work was declared unavailable by suspension of
the Rules.

Although Gronovius (1760) never has been
ruled on by the Commission it follows the same
system of nomenclature as does Gronovius (1763)
and clearly is not binominal. The same is true of
Gronovius (1762), which has been rejected (Opin-
ion 332). Under the provisions of the present Code
(Article 11(c)), names published in Gronovius
( 1 760) are not available as the author did not con-

100

COHEN and RUSSO VARIATION IN FOURBEARD ROCKLING

sistently apply the principles of binominal
nomenclature. Although Article ll.(c)(i) ("Uni-
nominal genus-group names published before
1931 without associated nominal species are ac-
cepted as consistent with the prmciples of binomi-
nal nomenclature, in the absence of evidence to
the contrary.") might serve as a basis for arguing
that the names in Gronovius ( 1760) are available,
the interests of stability would be served best by
considering the work unavailable, as its accep-
tance would require not only that Enchelyopiis
Gronovius 1760 replace Zoarceg Cuvier 1829, but
also that Cyclogaster Gronovius 1760 replace
Liparis Scopoli 1777.

If Gronovius (1760) is considered as unavailable
for purposes of zoological nomenclature then the
first valid use of Enchelyapus is by Bloch and
Schneider (1801). The type-species was stated by
Jordan (1917) as Gadus cimbrius Linnaeus 1766
as first restricted, and Svetovidov (1973) gave the
type as Gadus cimbrius Linnaeus 1766 by
monotypy. However, neither of these methods of
type fixation is correct as Bloch and Schneider
referred 12 species to the genus, and although
cimbriua is the first one in order, there is no action
that could be construed as a type designation. The
earliest type designation for Enchelynpus Bloch
and Schneider 1801 that we have been able to find
is that of Jordan (1917) as Gadus cinibrius Lin-
naeus 1766.

Rhinonemus Gill (1863a) was proposed for
Motella vaudavuta Storer 1848, a junior synonym
of Gadus cimbrius Linnaeus (Goode and Bean
1879) and is therefore a junior synonym of En-
chelyopus Bloch and Schneider.

ACKNOWLEDGMENTS

We are grateful to A. Wheeler for information
and discussions about rockling taxonomy, P.
Szarek for allowing us to read her unpublished
manuscript, and S. Johnson for information on
zoarcid nomenclature. For reading and comment-
ing on all or part of the manuscript we thank A.
Cohen. B. Collette, L. Dempster. M. Fahay, and W.
I. Follett. G. S. Myers assisted by allowing access
to rare literature. For access to study material we
thank D. McAllister, National Museums of
Canada; R. Jenkins, Cornell University; J.
Kaylor, NMFS, NCAA, Gloucester, Mass.; M.
Dick, Harvard University; R. Wigley, NMFS,
NCAA, Woods Hole, Mass.; C. Wenner and J.
Musick, Virginia Institute of Marine Science; G.

Jonsson, Marine Research Institute, Reykjavik; J.
G. Nielsen. University of Copenhagen; A.
Wheeler. British Museum (Natural History); and
M. L. Bauchot, Natural History Museum. Paris.
For assistance with computer processing we
thank K. K. Beach, E. M. Hamilton, and the Office
of Technical Assistance at The George Washington
University Center for Academic and Administra-
tive Computing. Figures 1-4 were prepared by
Keiko Hiratsuka Moore. George Clipper took
X-ray photographs. Histological sections of the
dorsal fin were prepared by Margaret Melville.
The manuscript was typed by A. McClain and V.
Tucker.

LITERATURE CITED

ANDRIYASHEV, A. P.

1954. Ryby severnykh moryei SSSR. Opred. Faune
SSSR53,566p,Akad.Naul5SSSR, iTransl 1964, Fishes
of the northern seas of the U.S.S.R. Keys to the fauna of
the U.S.S.R. 53. 617 p.. U.S. Dep. Commer,, Natl.Tech. Inf.
Serv., Springfield. Va. OTS 63-11160.1

1973. Zoarcidae. In J C. Hureau and Th Monod
(editorsi. Check-list of the fishes of the north-eastern At-
lantic and of the Mediterranean. Vol. I, p. 540-547. UN-
ESCO. Pans.

Battle, H. I.

1930. Spawning periodicity and embryonic death rate of
Enchelynpus cimhrws iL.) m Passamaquoddy bay. Con-
trib. Can. Biol. Fish., New Ser. 5:363-380.
BICELOW, H. B., AND W. C. SCHROEDER.

1953. Fishes of the Gulf of Maine. U.S. Fish Wildl. Serv.,
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102

COHEN and RUSSO: VARIATION IN FOIIRBEARD ROCKLING

APPENDIX

The following abbreviations indicate institu-
tions or collections: CU, Cornell University; MCZ.
Museum of Comparative Zoology, Harvard Uni-
versity: MNHN, Museum National d'Histoire
Naturelle, Pans: NEFC, Northeast Fisheries
Center, Woods Hole, Mass.; NMC, National
Museum of Natural Sciences, Ottawa: USNM, Na-
tional Museum of Natural History, Washington.
D.C.; ZMUC, Zoologisk Museum, Copenhagen.
The "Intermediate" region, below, extends from
about lat. 35"N to about lat. 37°N in the western
Atlantic.

Enchelyoptis cimhriin

GULF OF MEXICO— USNM 190346 (3 speci-
mens), Si/wrSavstn 294, 27°54'N,95°23'W, 79m.
USNM 217843 (16), Oregon 3724, 29°04'N,
88°31'W, 403 m. USNM 217939 (1), Oregon .5795,
24'16'N. 82'30'W, 439 m.

SOUTHERN ATLANTIC— USNM 217923 (2),
Silver Bay 1611, 29°06'N, 80°00'W, 339-384 m.
USNM 217924 (2), Silver Bay 223, 29°14'N,
80°05'W, 247 m. USNM 217935 (1), Oregon 5798,
29n4'N, 80°05'W, 357 m. USNM 217933 (5). Ore-
gon 5098, 29°17'N, 80°05'W, 379 m. USNM

217931 (1), Silver Bay 4227, 29°20'N, 80°05'W,
348 m. USNM 217949 ( 2 ), Silver Bay 224, 29°29'N,
80°09'W, 329 m. USNM 217937 (1), Combat 475,
29^30 'N, 80°10'W. 293 m. USNM 217934 (3) Ore-
gon 5093, 29''31'N, 80'=09'W, 384 m. USNM

217932 ( 1 ), Silver Bay 219, 29°34'N, 80°09'W, 348
m. USNM 217917 (1), Silver Bay 1607, 29°34'N,
80°09'W, 371 m. USNM 217943 (1). Combat 325,
29'35'N, 80°10'W, 366 m. USNM 217936 (1),
Combat 314, 29°38'N, 80°11'W, 329 m. USNM
217918 ( 1 ), Oregon 5238, 29°39'N, 80°12'W, 348 m.
USNM 217916 (2), Silver Bay 1606, 29°40'N,
80°12'W, 348 m. USNM 217940 (1), Silver Bay
217, 29°41'N, 80°08'W, 348 m. USNM 2~17919 (2),
Silver Bay 458, 29°49'N, SO'IO'W, 220 m. USNM
217921 (2), Silver Bay 1552, 29°43'N, 80°12'W,
302 m. USNM 217948 (1), Combat 435, 29°46'N,
80"12'W. 366 m, USNM 217920 (1), Silver Bay
3742, 29"50'N, 80'13'W, 275 m. USNM 217950 (5i,
Silver Bay 1604, 29°50 'N, 80°10 'W, 302 m. USNM
217947 (2), Silver Bay 3678, 29''53'N. 80ni'W,
329 m. USNM 217944 (3), Silver Ba\ 3675,
29°55'N, 80'1 1 'W, 329 m. USNM 217922 ( 1 ) Silver
Bay 4367, 29°55'N, 80°11'W, 320m. USNM

217945 (1), Oregon il), 5233, 29°54'N, 80°10'W,
348 m. USNM 217925 il). Combat 471, 29°57'N.
80°12'W,329m.USNM217946(3),Pe/(co/! 182-8,
32''09'N, 79°02'W, 275 m. USNM 217938 (1),
Combat 300, 32°15'N, 78°51'W, 348 m. USNM
217927 ( 1 ), Combat 289, 33°03 'N, 77°09'W, 366 m.

INTERMEDIATE— USNM 45898 (1), A/6o-
/ms.s-.35°40'N,74'52'W. USNM 45895-6 (7), A/6o-
tross. 36°02'N, 74°48'W. USNM 217941 (1), Ore-
gon II 10763, 36°01'N, 74=48'W, 311-567 m.
USNM 217951 (1), Oregon II 10664, 36°12'N,
74^47 'W, 249-329 m. USNM 217942 (2), Oregon II
10724, 36°14'N, 74"45'W, 366-421 m. USNM
217929 (2), Columbus helm 73-10-40, 36°33'N,
74°42'W, 296 m. USNM 217928 (3), Columbus
Iselin 73-10-47, 36°37'N, 74°42'W, 316 m. USNM
217926 (3), Columbus Iselin 73-10-89, 37°02'N,
74°38'W, 367 m. USNM 217930 (7), Columbus
Iselm 73-10-73, 37'05'N, 74''43'W, 194-479 m.

NORTHERN ATLANTIC— USNM 28994 (1),
Albatross. 38'39'N,73n 1 'W, 238 m. USNM 45969
(1), Albatross, 38°54'N, 72°51'W. USNM 28917
(li, 39°43'N, 7r32'W. USNM 45891 (1), A/6o-
//w,s, 39°48'N, 71°49'W. MCZ 37492 ( 1 ), Capt. Bill

II 20, 39°57'N, 7r07'W, 412 m. USNM 28843 (1),
Fish Haivk, 39°57'N, 70°32'W. USNM 28816 H),
39°N, 7rW. MCZ 38039 (1), Caryn 3-1, 39°59'N,
70'48'W, 381 m. USNM 33352 il ), Fish Hawk,
40°20'N, 70°35'W. USNM 28709 il), 40°24'N,
70°42'W. USNM 35680 (1), 40°21'N, 70°29'W.
USNM 28890 (2). 40°28'N, 70°44'W. USNM
126948 (1), Fish Hawk, Long Island Sound, 22 m.
USNMuncat.ll),A/6a^roi;,s/V,4ri4'N,71°41'W.
USNM 213501 (7), Blesk 68-18, 22-01, 4r52'N,
68°12'W, 198 m. USNM uncat. (1), Blesk 68-18,
24-02, 41°36'N,68''52'W, 138 m. USNM uncat.(l),
Blesk 68-18, 28-01, 42°N, 69°39'W, 210 m. USNM
16656 ( 1 ), Woods Hole. Mass. CU 18353 ^'i). Alba-
tross HI 27-45, 41"53'N, 69°10'W, 212 m. USNM
uncat. (1), Delaware 60-1-11, 4r52'N,
68n4'W, 227 m. CU 18274 ( 1 ). Albatross III 61-1,
4r49'N, 68°14'W, 154 m. USNM 23761 (1), Prov-
incetown, Mass. CU 45869 ( 1 ), Albatross IV 63-5-
69, 42'07'N, 67°3rW. NEFC uncat. (3), Albatross

III 70-23, 42°10'N, 68°38'W, 183 m. NEFC uncat.
(1), Albatross III 101-103, 42°15'N, 67°10'W, 168
m. CU 23620 (3), Albatross III 27-55, 42°41'N,
69°49'W, 256 m. NEFC uncat. (1), Albatross HI
47B-3-2, 42^41 'N, 70"09'W, 84-139 m. USNM
839251 1 ). Mass. Bay. USNM 2 1918 (I ). .Mass. Bay,

103

134 m. USNM 131920 (6), Mass. Bay. USNM
21918-9 (2), Mass. Bay. MCZ 34614 (3), 42°56'N,
70°18'W, 165 m. MCZ 34611 (3), Albatross II.
43°07'N. TOMO'W, 154 m. USNM 37847 (1 i,
Ipswich Bay. Ma.ss. MCZ 34612 (9), Alhutmss II,
43°03'N, 76°09'W. USNM 45897 (1), Albatross.
43°34'N, 63°56'W. MCZ 34613 (4), 43°39'N,
68°12'W. 192 m. MCZ 12340 ( 1 ), Eastport, Maine.
USNM 39060 (1), Prince Edward Island. USNM
43229 tl), 47°15'N, 53°58'W. NMC 63-151 (li,
51"28'N, 53°52'W.

GREENLAND— ZMUC uncat. (1), Adolf Jen-
sen 4420, 64°22'N. 52°54'W, 460-540 m.

ICELAND— ZMUC 95-96, (2), North coast of
Iceland, ca. 66°N, 18°30'W. ZMUC 830-32 (3),
Vestman Islands. ZMUC 26-27 (2), 63°46'N.
22°56'W. ZMUC P379 ( 1 ). south of Iceland. USNM
217909 (1), 65°37'N, 2r00'W. 110 m. USNM
217911 (1), 65°41'N, 2r20'W, 137-152 m.

EUROPE— USNM 39724 ( 1 ), Denmark. ZMUC
84-85 (2), 90-93 (4), 501, 503-4 (3), P37284-292 (9),
P37294-96 (3), P37298 (1), Denmark. ZMUC
P37283 (U, Limfjord, Denmark. P37297 1 1). Kal-
lundbors Fjord, Denmark. ZMUC 88 1 1 I. 502 1 1 I.
Snekkersten. Denmark. ZMUC 86 ill, 98 (li,
Oresund, Denmark. ZMUC 22-23 (2), Skagerak,
200 m. ZMUC 25 (1), off Lindesnds. Norway, 220
m. USNM 44514 (li, Drobak, Norway.

AFRICA— MNHN 38-110/111 (2i, off Cape
Blanc, Mauritania.

Ciliata imntcla

USNM 130840 (4). Europe. USNM 44510 (1),
Norway. USNM 216711 (2), Oresund, Denmark.

FISHERY BULLETIN VOL. 77, NO. 1

cm at a septentriona lis

ZMUC 371656-7 i2i, Faroe Islands.

Ga idropsa riis a rgeu tutu .v

MCZ 38353,38387 (2), western North Atlantic.
USNM 217907 (1), Iceland. USNM 217912 (1),
Iceland. USNM 217910 (1), Spitsbergen. USNM
217908(2). Iceland.

Gil /(Jruf) iiirm e n .v is

MCZ 37554 111, we.stern North Atlantic. MCZ
27882 1 1 1, western North Atlantic. MCZ 38425 ( 1 1,
western North Atlantic. MCZ uncat. I li. western
North Atlantic. USNM 217913 1 1 1, western North
Atlantic.

GaidropSiirns iiiittutin

USNM uncat. i2i. ill, (5i, San Miguel Island,
Azores.

Gaidropscinis tuediterraneiis

USNM uncat. ill, Tunisia.

Ga idropsa rns t ii /ga ris
USNM uncat. ( 1 ), 1 1 1, l3i, Tunsia.

Gaidropsanis sp,
USNM uncat. l5i, Amsterdam Island.

104

EARLY DEVELOPMENT OF SEVEN FLATFISHES OF
THE EASTERN NORTH PACIFIC WITH HEAVILY PIGMENTED LARVAE

(PISCES, PLEURONECTIFORMES)

B. Y. SuMiDA, E. H. Ahijstrom, and H. G. Moser'

ABSTRACT

Eggs and larval series are described for six species of flatfishes occurring off California with heavily
pigmented larvae. These are the pleuronectids Pleuronichthys coenosus, P decurrens, P. ntteri, P.
verticalis. and Hypsopselta guttulata and the bothid. Hippoglossina stomata. A brief description of
postflexion larvae of the Gulf of California species. P ocellatus, is also presented.

Eggs of Pleuronichthys are unusual among flatfishes in possessing a sculptured chorion composed of
a network of polygonal walls, whereas the chonons of Hypsopsetta guttulata and Hippoglossina
stomata eggs are smooth and unomamented. Eggs o{ Hypsopsetta guttulata and P. ritteri are unusual
among those of pleuronectid flatfishes in possessing an oil globule.

A combmation of pigmentation, morphology, and meristics can distinguish the seven species of
flatfishes with heavily pigmented larvae. Larvae of two species, H guttulata and P. decurrens, have a
distinctive pterotic spine on either side of the head. Sizes at hatching, at fin formation, and at
transformation are important considerations to distinguish these species. Meristic counts, particularly
of precaudal and caudal groups of vertebrae, are important to relate a larval series to itsjuvenile and
adult stages and thus substantiate identification of the series.

This report deals primarily with the eggs, larvae,
and early juveniles of flatfishes of the genus
Pleuronichthys. Descriptions are included for
complete series of larvae of four species, P. decur-
rens (curlfin turbot),* P. coenosus (C-0 turbot), P.
verticalis (hornyhead turbot), and P. ritteri (spot-
ted turbot). A brief account of postflexion larvae of
the Gulf of California species, P. ocellatus (Gulf
turbot), is also given. Larvae of Pleuronichthys are
heavily pigmented, even at hatching, as are those
of the pleuronectid, Hypsopsetta guttulata
(diamond turbot), and the bothid, Hippoglossina
stomata (bigmouth sole). To identify heavily pig-
mented flatfish larvae obtained in plankton collec-
tions from the eastern North Pacific, it is neces-
sary to know the larval developmental, series of all
of the above species. These species comprise minor
incidental catches within California commercial
and sport fisheries and are reported as a general

'Southwest Fisheries Center La JoUa Laboratory. National
Marine Fisheries Service. NOAA. P.O. Box 271. La Jolla. CA
92038.

^The common name turbot is used for all species of
Pleuronichthys. a usage consistent with Fitch ( 1963). Miller and
Lea (1972). and Gates and Frey (1974:79). The American
Fisheries Society's list of common names (Bailey et al. 1970)
designates P. coenosus and P decurrens as soles, but we disagree
with giving species within a genus different common general
names.

Manuscnpt accepted September 1978.
FISHERY BUIXETIN VOL. 77, NO. 1, 1979.

grouping of "turbots." Species most commonly
caught in the fisheries are P. decurrens. P.
coenosus, P. verticalis, and Hypsopsetta guttulata
(Frey 1971; Bell 1971; Oliphant 1973; Pinkas
1974; McAllister 1975). No specific catch data are
available for Hippoglossina stomata, but the
species is probably caught incidentally and in-
cluded in the "miscellaneous sole" category of
catch data.

In a review of the genus Pleuronichthys, Fitch
(1963) recognized six species including the five
listed above and P. cornutus from off Japan and
China. In an earlier review of the genus, Starks
and Thompson ( 1910) recognized these six species
and P. nephelus Starks and Thompson. Norman
(1934) concurred with Starks and Thompson in
recognizing seven species. Fitch (1963), however,
agreed with Hubbs (1928) in finding no grounds
for the separation of P. nephelus from P. coenosus
after his examination of the type material of P.
nephelus. Fitch's review is thorough; he examined
more than 5,700 individuals of the genus. We fol-
low his classification.

The first descriptions of the eggs and early-stage
larvae of Pleuronichthys were given by Budd
(1940) who dealt with P. coenosus, P. decurrens.
and P. verticalis. Orton and Limbaugh (1953) de-
scribed the eggs of Hypsopsetta guttulata and P.

105

FISHERY BULLETIN VOL 77. NO. 1

ritteri. Larvae of P. verticalis were illustrated in
Ahlstrom and Moser (1975), and Eldridge (1975)
described and illustrated larvae of//, guttulata.

MATERIALS AND METHODS

Eggs, larvae, and somejuveniles were primarily
obtained from California Cooperative Oceanic
Fisheries Investigations (CalCOFI) collections.
These samples were preserved in a consistent
manner as described in Kramer etal.( 1972). Addi-
tional material was obtained from bay, estuarine,
and coastal collections of Occidental College;
Southwest Fisheries Center Tiburon Laboratory,
National Marine Fisheries Service; California
State University at Fullerton; Scripps Institution
of Oceanography; Oregon State University; and
Humboldt State University. Specimens of P. rit-
teri, P. verticalis, and H. guttulata reared at the
Southwest Fisheries Center La Jolla Laboratory,
National Marine Fisheries Service, were also
utilized.

Egg and oil globule diameters were measured
using an ocular micrometer in a stereomicroscope.
For eggs that were not perfectly round, the
greatest diameter was recorded. Scanning elec-
tronmicrographs were made for four kinds of
Pleuroniehthys eggs and for eggs of Sy nodus
lucioceps (Synodontidae). The greatest diameter
of 10 randomly selected polygonal facets of the
chorion of Pleuronichthys and Synodus eggs were
measured using an ocular micrometer in a com-
pound microscope. To do this the chorion was cut
into pieces that were laid flat on a glass slide with
a cover slip over them.

The number of specimens examined varied by
species, depending on their availability and abun-
dance, ranging from several hundred larvae of P.
verticalis, the most abundant species, to two lar-
vae of P. ocel lotus. For most species, the minimum
number of specimens studied is indicated in the
morphometric tables with usually twice as much
material looked at for pigmentation development.
A developmental series of larvae through
juveniles was assembled for each species. Mea-
surements of selected body parts were taken to
provide descriptive and comparative morphomet-
ric data. Measurements were made on the right
side of each pleuronectid specimen, and on the left
side of the bothid, Hippoglossina stomata, using
an ocular micrometer in a stereomicroscope. Ter-
minology used in the morphometric tables is as
follows:

Body length = In preflexion and flexion stages,
horizontal distance from tip of snout to tip of
notochord, referred to as notochord length
(NL); in postflexion stages, from tip of snout
to posterior margin of hypural elements, i.e.,
standard length (SL).

Snout to anus = Horizontal distance from tip of
snout through midline of body to vertical
through anus.

Head length = Horizontal distance from tip of
snout through midline of head to margin of
cleithrum preceding the pectoral fin base.

Snout length = Horizontal distance from tip of
snout to anterior margin of pigmented re-
gion of eye.

Eye width = Horizontal distance through midline
of pigmented eye.

Eye height = Vertical distance through center of
pigmented eye.

Body depth at pectoral base = Vertical distance
across body at pectoral fin base prior to for-
mation of dorsal fin pterygiophores. An as-
terisk follows this measurement in the mor-
phometric tables when it includes the depth
of dorsal fin pterygiophores.

Body depth at anus = Vertical distance across
body at anus prior to formation of dorsal fin
pterygiophores. An asterisk follows this
measurement when it includes the depth of
the dorsal fin pterygiophores.

Caudal peduncle depth = Vertical distance across
tail immediately posterior to terminal dor-
sal and anal fin rays.

Caudal peduncle length = Medial horizontal dis-
tance from vertical through terminal dorsal
and anal fin rays to posterior margin of
hypural elements.

Snout to pelvic fin origin = Horizontal distance
from tip of snout to vertical through origin of
right pelvic fin (left in H. stomata).

Larval specimens for each species were not
available in sufficient numbers to clear and stain
for complete data on meristics and sequence of
ossification of bony elements. However, fin ray
counts were made and tabulated on unstained
specimens. A partial larval series of P. verticalis,
our most abundant species, was cleared with KOH
and stained with Alizarin Red-S by Hollister's
method (1934) to determine the process of axial
skeletal development and fin formation. In addi-
tion, several larvae of P. coenosus and P. decur-
rens were cleared and stained for precaudal and

106

SUMIDA ET AL EARLY DEVELOPMENT OF SEVEN FLATFISHES

total vertebral counts which verified identifica-
tions and proved that Budd (1940) confused iden-
tifications of larvae of these two species. Radio-
graphs of transforming larvae, juveniles, and
adults of each species provided additional meristic
data.

We divide the larval period into three stages,
preflexion, flexion, and postflexion, based on the
flexion of the notochord which occurs during
caudal fin formation (Moser and Ahlstrom 1970;
Ahlstrom et al. 1976; Moser et al. 1977). In
Pleuronichthys and some other flatfishes the initi-
ation of caudal fin formation begins while the
notochord is still straight, in the late preflexion
stage; we designate this phase as "early caudal
formation." We found it convenient to divide the
flexion stage into three substages, early flexion,
midflexion, and late flexion, dependent upon the
state of flexion of the notochord. In the early flex-
ion stage, the notochord is very slightly flexed
upward; in midflexion, it is flexed midway (nearly
a 45° angle); and in late flexion, the notochord is
approaching a terminal position, except that the
caudal rays remain in a slightly oblique position.
Transformation from the larval to juvenile stage
was marked by eye migration, development of os-
sified pectoral fin rays, scales, and the lateral line.

MERISTIC COUNTS OF LARVAE

Meristic counts overlap among species consid-
ered here, and for discrimination of species it is
necessary to use a combination of counts (Table 1).
Precaudal and caudal vertebral counts, used in
conjunction with dorsal and anal fin counts, are of
most use in relating larvae to juveniles or adults.
Pelvic fin ray counts are six per side in all seven
species and branchiostegal ray counts are seven
per side. Pectoral fin counts cannot be made on
larvae since ossified pectoral rays form at
metamorphosis. Gill rakers are not fully formed
during the larval period in the species described.

DESCRIPTION OF EGGS

Pleuronichthys spp.

Eggs of three Pleuronichthys species were first
described by Budd (1940) who collected them in
plankton hauls from Monterey Bay, Calif. Budd
noted the hexagonal patterns on the chorions of
Pleuronichthys eggs. This type of ornamentation
of the egg shell is confined to Pleuronichthys
among flatfishes, but similar polygonal sculptur-
ing is found on eggs of the families Synodontidae
(Sanzo 1915; Mito 1961) and Callionymidae (Holt
1893; Ehrenbaum 1905; Mito 1962) and in a more
exaggerated form on eggs of the sternoptychid,
Maurolicus muelleri (Sanzo 1931; Mito 1961). and
the macrourid, Coelorhynchus coelorhynchus
(Sanzo 1933). Eggs of the three species of
Pleuronichthys described by Budd were strikingly
different in size; his largest, P. coenosus, averaged
1.88 mm in diameter, his intermediate-sized egg,
P. decurrens , 1.44 mm, and his smallest, P. ver-
ticalis, 1.07 mm. All had homogeneous yolk, and
lacked an oil globule. Our work shows that Budd
misidentified the two larger eggs and correspond-
ing larvae; the one he called P. coenosus is P.
decurrens and vice versa. Orton and Limbaugh
1 1953) described an egg with an hexagonal pattern
on its chorion that possessed a single oil globule;
they tentatively, but correctly, assigned it to P.
ritteri. White ( 1977) illustrated a developing egg of
P. ritteri from Newport Bay, Calif

Information concerning egg diameters, pres-
ence or absence of an oil globule, and character of
the chorion are given in Table 2 for six of the seven
species treated in this paper. Egg diameters do not
change noticeably with the duration of preserva-
tion, although some shrinkage is known at the
initial time of preservation. There is no overlap in
egg size for the three species of Pleuronichthys
that lack an oil globule. Eggs of P. decurrens range
from 1.84 to 2.08 mm; those of P. coenosus, from

Table l. — Meristics of the seven species of flatfishes in the eastern North Pacific that have heavily pigmented larvae.'

Pectoral

Caudal

rays
(eyed side)

Species

rays

rays

Precaudal

Caudal

Total

giK rakers

Total

Branched

Pleuronichthys decurrens

67-81

46-55

10-14

14-15

24-26

38-41

9-12

79-21

12-15(73)

P coenosus

66-78

44-56

9-12

12-73

24-26

37-39

11-15

1 8-20{ 1 91

12-15(73)

P verticals

66-79

44-51

10-12

13

23-25

36-38

9-11

79-20

12-14(73)

P ocellatus

62-74

44-53

10-12

12-13

22-24

34-36

10-14

19

12-15(73)

P rinen

62-72

43-52

9-11

72-13

22-24

34-36

12-17

18-79

73-14

Hypsopsetta gunutata

65-75

47-55

11-13

11-72

22-24

34-36

7+^(5-6)

79-20

13

Hippoglossina stomata

63-70

47-55

11-12

IJ

26-28

37-39

15-21

17'2-)8t

11-73

'Menstics compiled in Table 1 are derived in partfrom literature, particularly Fitch (1963). Norman (1934), Townsend (1936). Clothier (1950). and Ginsburg
(1952), and m part from our onginal counts Where a range is given and one count is predominant, that count is italicized
^Lower limb count only

107

FISHERY BULLETIN VOL 77, NO, 1

Table 2, — Measurements of eggs of Pleuronichthy^ species, Hypsopsetta guttulata, and HippogLossina stomata, including

Synodus lucioceps for comparative data.

Oil globule diameters

No 0(

Egg diameters (mm)

(mm)

Species

o( chorion

measured

samples

Range

Mean

SD

Range Mean

SD

Pleuronichthys decurrens

Sculptured

41

28

1 84-2 08

1,97

058

P coenosus (CalCOFI)

Sculptured

20

15

1 28-1 56

1 47

0066

— —

—

P coenosus (King Harbor)

Sculptured

287

2

1 20-1 42

1 29

0047

— —

—

P. verticatis

Sculptured

188

19

1 00-1 16

1.09

0040

— —

—

P rinen

Sculptured

82

13

94-1 08

1 01

0029

008-0 14 10

009

Hypsopsetta guttulata

Smooth

35

4

78-0 89

0,84

0027

12-0 14 13

010

Hippoglossina stomata

Smooth

26

9

1 22-1 38

1,29

0,045

0,20-0 26 23

0018

Synodus lucioceps

Sculptured

168

8

1 20-1 48

1,32

0049

— —

—

1.20 to 1.56 mm; and those of P. uerticalis, from
1.00 to 1.16 mm. Although eggs of P. ritteri, rang-
ing in diameter from 0.94 to 1.08 mm, fall within
the size range of P. verticalis. they can be readily
distinguished by the presence of a small oil
globule, 0.08-0. 14 mm in diameter. Eggs of P. ocel-
latus were unavailable.

Differences in mean diameter of P. coenosus
eggs were noted by locality, with eggs taken in
open waters off the coast having a larger mean
diameter and standard deviation (Table 2, Cal-
COFI collections) than eggs sampled from the
inlet of a small, shallow, manmade harbor near a
power plant discharge (Table 2, King Harbor sam-
ples). Except that they are often slightly larger in
size, early- and middle-stage eggs of P. coenosus
are difficult to differentiate from Synodus
lucioceps eggs. They can be separated, however, by
careful examination of the size and arrangement
of polygons on the chorion. The mean of the
greatest distance across polygons (sample
size = 200 polygons) on P. coenosus eggs is 0.035
mm in contrast to 0.047 mm for S. lucioceps eggs
(Table 3). Furthermore, the polygons on P.
coenosus eggs are more regular in arrangement
than on S. lucioceps eggs (Figure 1). This more
uniform compacting of smaller polygons on P.
coenosus eggs versus a more random patterning of
larger polygons on S. lucioceps eggs is visible
under a light microscope, and will separate these
eggs. Late-stage eggs are easily distinguished by
the heavy pigmentation on the embryo of P.
coenosus compared with the sparse pigment on

Table 3, — Comparison of polygon size on chorion of eggs of
Pleuronichthys and Synodun lucioceps.

No ot

No of

Range ot

eggs

polygons

diameters

Mean

SD

Species

measured

measured

(mm)

(mm)

(mm)

Synodus lucioceps

20

200

038-0,053

0,047

0,0033

Pleuronichthys

coenosus

20

200

029-0 043

035

0029

P decurrens

2

20

038-0 046

042

0021

P verticalis

2

20

037-0 051

042

0046

P ritteri

2

20

0,028-0032

0,030

0011

advanced S. lucioceps embryos, which also have a
longer gut.

The arrangement of polygons on the chorion of
eggs of the other three species of Pleuronichthys
from the eastern Pacific is similarly uniform (Fig-
ure 2). The polygons are somewhat larger on the
chorion of eggs of P. decurrens and P. verticalis
than P. coenosus, averaging ca. 0.042 mm in both
species (Table 3). Interestingly, Budd ( 1940) gave
the identical value, 0.042 mm, for this measure-
ment on eggs of these two species. The polygons
are smaller on eggs of P. ritteri. averaging 0.030
mm.

The eggs of P. cornutus were described by Mito
( 1963) and Takita and Fujita ( 1964). Mito gave the
egg diameters as 1.16-1.26 mm, the oil globule as
0.016-0.020 mm. Takita and Fujita gave similar
measurements for the hexagonal meshes of 0.018
mm, but gave a smaller egg diameter of 1.03-1.11
mm.

Hypsopsetta guttulata

Orton and Limbaugh (1953) obtained running
ripe eggs of//, guttulata by stripping ripe adults
and obtained similar eggs from plankton collec-
tions. The eggs were notable in that they con-
tained a conspicuous, moderately large oil globule.
This was the first record of an oil globule in eggs of
flatfishes of the family Pleuronectidae, subfamily
Pleuronectinae. The egg capsule was simple,
without polygonal sculpturing or other apparent
texture; the yolk was homogenous. Orton (1953)
gave a fairly detailed description of pigment de-
velopment on embryos of//, guttulata. Neither of
the above papers contained information on egg
size. Eldridge (1975) reported a mean egg diame-
ter of 0.80 mm with usually one oil globule of 0.14
mm in mean diameter and numerous other small
oil globules in the yolk. Eggs in our samples had a
mean diameter of 0.84 mm (range 0.78-0.89 mm)
with a single oil globule averaging 0.13 mm in

108

SUMIDA ET AL . EARLY DEVELOPMENT OF SEVEN FLATFISHES

FiGL'RE 1. — Scanning electronmicrographs of Pleuronichthys and Synodus lucwceps eggs. A. Entire egg of P. coenosus, 40 v ; B.
Single polygon from same egg showing micropyle and texture of chorion surface, 1 ,880 ^■, C. Side view of same egg showing polygons in
perspective and micropyle at lower left. 420 « ; D. Face view of same egg, 480 ; E. Side view of .S. /ucioceps egg showing polygons in
perspective, 455 ^ ; note delicate nature of polygons; F. Face view of same egg showing irregular nature of polygons and smooth surface
of chorion, 490 .

109

FISHERY BULLETIN VOL 77. NO 1

9

^^sSSi

Figure 2. — Scanning electromicrographs of P/ewronfc/j^A_vs eggs. A. Side view of P. decurrens egg. 475 x; B. Face view of same egg,
475x; C. Side viewofP. wrtica/is egg. 410 X; D. Face view ofsame egg. 450 x; E. Side view of P. n«m egg. 460 x; F.Faceviewof
same egg, 475 x.

110

SUMIDA ET AL.: EARLY DEVELOPMENT OF SEVEN FLATFISHES

diameter (Table 2). There was no evidence of other
small oil globules in the yolk, although a few eggs
had a damaged oil globule which had separated in
two. However, the original oil globule could easily
be determined because of surrounding pigment.
The oil globule is positioned near the center of the
developing embryo in middle-stage eggs. The body
of the late-stage embryo is heavily pigmented,
similar to the newly hatched larvae.

Hippoglossina stomata

Eggs of H. stomata have not been previously
described. Eggs are round with a slightly pinkish,
unornamented shell and a single oil globule. The
egg has a mean diameter of 1.29 mm (range 1.22-
1.38 mm) and the oil globule a mean diameter of
0.23 mm (range 0.20-0.26 mm) (Table 2). The oil
globule lacks pigment and lies near the tip of the
tail of developing embryos in middle-stage eggs. In
late-stage eggs the oil globule is in the posterior
part of the yolk sac; the embryo is heavily pig-
mented over the body except for the posteriormost
portion of the tail; pigment patches occur on the
finfolds in the same places as in early preflexion
stage larvae; pigment is widespread over the yolk
surface.

DESCRIPTION OF

DEVELOPMENTAL STAGES— LARVAL,

TRANSFORMING, AND EARLY

JUVENILE

Pleuronichthys decurreiis Jordan and

Gilbert (curlfin turbot)

Figures 3, 4

Literature. — A series of egg stages and two preflex-
ion larvae of P. decurrens were described and il-
lustrated by Budd ( 1940) but incorrectly identified
as P. coenosus. His larval illustrations,were based
on a recently hatched specimen, 5.54 mm, and an
emaciated specimen. 8 days old, of somewhat
smaller size.

Distinguishing characters. — Larvae of this species
are unique in the genus Pleuronichthys in de-
veloping a pterotic spine on each side of the head,
in having a higher precaudal vertebral number of
14 or 15, and in having the largest larvae during
all stages of development. Larval pigmentation is
heaviest in this species with the body and finfold
entirely pigmented except for the posteriormost

region. Because of their relatively large size and
dense pigment, P. decurrens larvae cannot be con-
fused with Hippoglossina stomata or Hypsopsetta
guttulata.

Pigmentation. — Newly hatched, preflexion, and
early flexion larvae (4.9-9.8 mm NL) are heavily
pigmented over the head, trunk, tail, and finfolds
with only the pectoral fin and posteriormost tip of
the notochord and finfold unpigmented (Figure
3 A, B, C). As the first few caudal rays become
evident (ca. 9.7 mm NL), several small, discrete
melanophores appear on the pectoral fin base
(Figure 3Ci. In late flexion and early postflexion
stages during dorsal and anal fin development, the
continuous heavy pigment on the finfolds changes
to form three to four dorsal and three ventral
bands of pigment which extend out from the body
margin to part of the rayed fin membrane (Figure
3D). Larvae at this stage have a soft, saccular body
with semitransparent and sparsely pigmented
areas in the pterygiophore region between the
body proper and developing dorsal and anal fins.
Larvae >11.2 mm SL have dorsal and anal
pterygiophores fully developed; the pterygiophore
region is no longer transparent and the specimens
become robust (Figure 4).

Morphology. — Larvae of P. decurrens are the
largest members of the genus at hatching and
attain the largest size before transformation. Our
smallest specimen is 4.9 mm NL and has yolk
remnants (Table 4). The left eye begins to migrate
at 10.5 mm SL and has not completed migration in
a larva 21.0 mm SL. The smallest available
juvenile is 29.4 mm SL.

The gut begins as a tube which diminishes in
diameter posteriorly and ends with a free terminal
section that diverges from the body in a slight
posteriad direction. In 5- to 7-mm NL larvae, the
gut increases markedly in diameter and the free
terminal section becomes vertical to the body axis.
At about 8.0 mm NL, the gut begins to coil and its
terminal section begins to slant anteriad. Coiling
and the anterior displacement of the anus become
more marked as development proceeds. This is
reflected in the decreasing relative snout-anus
length in postflexion larvae and especially in
juveniles (Table 5).

Relative head length increases during larval
development whereas relative snout length de-
creases (Table 5). Relative eye width decreases
slightly during the three phases of the larval

111

112

SUMIDA ET AL., EARLY DEVELOPMENT OF SEVEN FLATFISHES

Figure 3. — Larval stages of Pleuronichthys decurrens: A. 5.9
mm; B. 6.5 mm; C, 9 7 mm; D 10.0 mm.

Figure 4. — Transforming specimen of Pleuronichthys decurrens. 14 A mm.

T.ABLE 4. — Morphometries, in millimeters, of larvae and a juvenile o( Pleuronichthys decurrens.
(Specimens between dashed lines are undergoing notochord flexion.)

Snout

Body

Body

Caudal

Caudal

Snout

Body

Lett

Noto-

to

Head

Snout

Eye

Eye

depth at

depth

peduncle

peduncle

to origin

Station

length

eyei

chord^

anus

length

length

width

height

P baseJ

at anus^

depth

length

pelvic fin

5401-90 60

4 9NL

Sym

Str

24

80

14

30

024

0,54

0,64

—

—

—

5704-87 50

56

Sym

Str

30

1 1

20

40

32

090

96

—

—

—

6501-63 52

60

Sym

Str

30

1 1

20

40

36

090

74

—

—

—

5206-70 65

65

Sym

Str

32

1 2

22

42

40

94

1 1

—

—

—

6501-60 70

79

Sym

Sir

39

1 6

30

50

48

1 3

1 3

—

—

—

5003-87 35

85

Sym

Str

4 1

18

32

60

56

1 7

1 8-

—

—

—

6606-60 65

93

Sym

Str

43

20

32

66

62

1 6

18-

—

—

—

6605-80 80

98

Sym

Str

43

2 2

36

68

064

20

2 2-

—

—

—

5706-93 65

78

Sym

E II

39

1 9

30

064

064

2 3-

23-

_

_

5711-87 55

9 1

Sym

Ell

4 7

2 1

40

70

66

2 4-

25-

—

—

—

5401-85 60

100

Sym

Midll

44

26

44

80

72

2.8-

3 0-

—

—

27

6507-87 55

110

Sym

L fl

58

32

48

98

1

40-

4 6-

—

—

33

5009-47 60

102 SL

Sym

Flexed

53

34

60

96

94

4 5-

4 6-

1

060

34

5407-60 70

105

Migr

Flexed

55

36

064

1 1

1 1

4 9-

5 4-

1

64

34

5805-70 80

11 2

Migc

Flexed

57

39

64

1 3

1 2

5 2-

59-

1 3

68

36

7505-90 70

14 5

Migr

Flexed

62

52

66

1 6

96

8 1-

86-

2 1

83

46

4903-82 57

154

luligr

Flexed

70

5 7

67

1 8

1 7

9 0-

9 7-

2 1

1 1

4 7

6609-80 60

170

Migr

Flexed

87

64

67

1 9

1 5

9 2-

11 4-

29

1 2

60

5308-73 60

192

f^4igr

Flexed

7 7

65

091

1 7

1 5

10 0-

11 4-

28

1 2

64

5004-97 32

21

Migr

Flexed

84

67

66

1 7

1 7

11 7-

124-

32

1 4

62

OtI Santa Cruz

Island, Calif

29 4

Over

Juv

97

90

66

33

25

139-

14 5-

36

22

68

'Sym - symmetrical. Migr migrating.

^Str - straight, E fl - early fleKion. Midll - midllexion, L fl late flexion. Juv - juvenile

^Asterisk indicates inclusion of dorsal fin pterygiopfiores in body depth measurement.

113

FISHERY BULLETIN: VOL 77, NO 1

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114

SUMIDA ET AL EARLY DEVELOPMENT OF SEVEN FLATFISHES

period and then increases sharply in juveniles (Ta-
ble 5). Relative eye height is consistently less
than eye width; this is the usual pattern among all
species being dealt with in this report.

The spine on each pterotic bone first appears on
larvae about 6.0 mm NL and achieves maximum
development in flexion larvae. It begins to regress
near the end of the larval period and is a rugose
bump in newly transformed juveniles. No other
species of Plciironichthys develops pterotic spines
during the larval period, although they are pres-
ent on larvae of H. guttulata.

Another distinctive feature of P. decurrens lar-
vae is body depth. As in other species of
Pleurontchthys. early larvae are slender. Relative
body depth increases markedly during the post-
flexion stage with the result that larvae of this
species become strikingly deeper bodied than
those of the other six flatfishes with heavily pig-
mented larvae (Table 5).

Fin and axicd skeleton formation. — Because this
species is larger at corresponding stages of de-
velopment than the other six flatfishes considered,
fin formation occurs at comparatively larger lar-
val sizes. Caudal fin development occurs between
7.9 and 11.0 mm NL; the smallest postflexion
specimen, 10.2 mm SL, has the full count of 19
caudal rays (Table 6). The dorsal and anal fins
begin forming simultaneously with the caudal,
but obtain their full complement of rays later, by

14.5 mm SL. Pelvic buds are evident on most
specimens undergoing flexion, but the full count of
fin rays was first obtained on a 15.4-mm SL speci-
men. The axial skelton is ossified on specimens as
small as 11.2 mm SL, as determined by radio-
graphs. Counts of 14 precaudal and 24-27 caudal
vertebrae were recorded on five postflexion speci-
mens.

Transformation. — Flatfish larvae are normally
symmetrical larvae with eyes opposite each other
on either side of the head during their preflexion to
flexion stages and into the postflexion stage. Some
flatfish larvae remain symmetrical with regard to
eye placement until attaining quite large sizes,
i.e., 50-120 mm (Hubbs and Chu 19.34; Bruun
1937; Nielsen 1963; Amaoka 1970, 1971, 1972,
1973). However, in the flatfishes being studied the
migration of one eye (left in dextral flounders,
right in sinistral flounders) begins early in the
postflexion stage. It can require some time to move
completely over. Thus, the left eye was migrating
on a 10.5-mm larva of P. decurrens, but was not
completely over on a 21.0-mm specimen. Ossified
rays are not formed in the pectoral fin until after
eye migration is completed. On first formation the
rays are spaced some distance apart in the blade of
the pectoral fin. The pectoral fin rapidly changes
form with the structure of the larval pectoral (base
and blade) disappearing, to be replaced by a group
of ossified, closely spaced rays. Metamorphosis is

Table 6. — Meristics of larvae and a juvenile of Pleuronuhthys decurrens.
(Specimens between dashed lines are undergoing notochord flexion.)

Station

Fin rays

Size

Pectoral

(mm)

stage'

Dorsal

Anal

Caudal

Pelvic

right/left

4 9 NL

Pretl

LP'

56

Prefl

LP'

60

Pretl

LP'

6.5

Prefl

LP'

7.9

Prefl

LP'

85

Prefl

Forming

Forming

Forming

LP'

93

Prefl

Forrning

Forming

4

LP'

98

Prefl

Forming

Forming

ca 8

LP'

Precaudal Caudal

Source
Total of count

5401-90 60
5704-87 50
6501-63 52
5206-70 65
6501-60 70
5003-87 35
6606-60 65
6605-80 80

5706-93 65

78

Efl

Forming

Forming

ca 8

Bud

LP'

5711-87 55

9 1

E (1

Forming

Forming

ca 12

LP'

5401-85 60

100

Midfl

Forming

Forming

ca 12

Bud

LP'

6507-87 55

11

L 11

ca 50

ca 42

17

Bud

LP'

5009-47 60
5407-60 70
5805-70 80
7505-90 70
4903-82 57
6609-80 60
5308-73 60
5004-97 32
Off Santa Cruz Island, Calif

10.2 SL Postfl

105

11 2
145
154
170
192
21
29 4

Postfl
Postfl
Postfl
PosttI
Posttl
Postfl
Postfl
Juv

50
ca 64
71
74
72
77
75
74
78

46
45
46
52
48
48
52
48
52

19
19
19
19
19
19
19

Bud
5/5
5/5
5/5
6/6
6/6
6/6
6/6
6/6

LP'
LP'
LP'
LP'
LP'
LP'
LP'
LP'
11/11

X-ray

25

39

X-ray

24

38

X-ray

27

41

X-ray

25

39

X-ray

26

40

X-ray

'Prefl - pretlexion, E fl - early flexion; Midfl - midflexion; L fl - late flexion. Postfl
^LP refers to functional larval pectoral fins whicfi fiave no ossified rays

postflexion, Juv - juvenile

115

considered complete when the lateral line can be
discerned and scale formation has begun.

Distribution.— Fitch (1963) reported that the
range for this species was from Alaska to San
Quintin, Baja California. Miller and Lea (1976)
gave an extended southern range limit to 25 mi
north-northeast of Cedros Island (lat. 28"47.5'N,
long. 114'57.0'W). Egg and larval material in our
collections was taken off the entire coast of
California over a broad band of stations, from
nearshore to 150 or more miles offshore ( Figure 5).
Lack of egg and larval material off Baja Califor-
nia, despite the intensive coverage of these waters
by CalCOFI surveys, indicates a more northerly
distribution for young stages than for adults.

Pleiirouichthys coeuosiis Girard
(C-O turbot)
Figures 6, 7

Literature.— YinM (1940) described and illus-
trated a series of eggs and four reared larvae of P.
coenosus which he mistakenly identified as P. de-
currens. The larvae illustrated were newly
hatched to 9 days old, ranging in size from 3.88 to
4.72 mm.

Distinguishing characters. — This species is dis-
tmguished by having 13 (rarely 12) precaudal ver-
tebrae and a total of 37-39 vertebrae. The larvae
are larger than comparable stages of//, guttulata
and other species oi Pleuronichthys except P. de-
currens. Pigmentation patterns discussed below
will al.so separate P. coenosus from other species
treated in this work.

Pigmentation. — Preflexion larvae are charac-
terized by having opposing, similar appearing,
pigment clusters on the dorsal and ventral finfolds
posterior to the anus, and by small melanophores
dotting the margin of the otherwise unpigmented
posterior tip of the tail (Figure 6A, B). The rest of
the body is heavily pigmented, with the exclusion
of the undifferentiated pectoral fin and the ventral
half of the head.

Flexion (6.2-7.8 mm NL) and postflexion larvae
(7.1-11.4 mm SL) show an increase anteriorly of
the finfold pigment and an increase in pigmenta-
tion on the lower region of the head (Figure 6C, D,
E). A distinctively narrow, unpigmented zone
along the hypurals persists through late flexion
specimens, but is subsequently pigmented in

129°

FISHERY BULLETIN: VOL. 77. NO, 1
125° 121°

40'

35'

30'

25'

20°

44°

40°

35°

30°

106°

Figure 5.— Distribution of eggs and larvae of Pleunmichthyn
decurrens examined in this study. (Triangles represent eggs,
open circles larvae, and closed circles eggs and larvae.)

FICIRE 6. — Larval stages o( Pleuromchthys coenosus: A. 3.7
mm; B. 5.9 mm; C. 6.1 mm; D. 7.8 mm; E. 8.9 mm.

116

SUMIDA ET AL,: EARLY DEVELOPMENT OF SEVEN FLATFISHES

117

nSHERY BULLETIN: VOL. 77, NO 1

postflexion specimens (Figure 6E). A few pigment
spots dot the anterior margin of the pectoral fin
base in postflexion specimens, and extend farther
onto the fin base in larger specimens. At dorsal
and anal fin formation, pigment clustered in the
finfold aligns along the dorsal and anal fin rays,
and later in postflexion specimens becomes com-
pacted into a narrow band adjacent to the fin
bases. Pigment over the pterygiophores, however,
is as dense as on the body (Figure 7).

Morphology . — Larvae of P. coenosus are larger at
hatching and at transformation than all other
species oi Pleuronichthys except P. decurrens. A
3.9-mm NL specimen has much of its yolk sac
remaining (Table 7). The smallest specimen in
which the left eye begins to migrate is 8.2 mm SL;
eye migration is almost complete in our largest
transforming specimen, 11.4 mm SL.

The gut begins to coil and the free section be-
comes vertical to the body axis in larvae between
5.5 and 6.0 mm NL. Snout-anus distance has a
moderate decrease relative to body length in all
larval phases and decreases markedly after trans-
formation (Table 5).

As in the other species, relative head length
increases during larval development through the
postflexion stage, but decreases moderately in
juveniles. Both relative snout length and eye size
decrease during the three larval phases (Table 5).

As in other species of Pleuronichthys, body
depth increases during each larval stage (Table 5).
Relative body depths for larvae of P. coenosus are
in the intermediate range compared with other
species in the genus. Body depth in juveniles is
comparable with that in the relatively deep-
bodied P. decurrens.

Fin and axial skeleton formation. — Fin formation
in P. coenosus takes place at smaller sizes than in
P. decurrens but at larger sizes than in other
species of Pleuronichthys. Larvae undergoing
caudal fin formation range from 6.2 to 8.5 mm NL.
The smallest fully flexed larva is 7.1 mm SL. The
full count of caudal rays is developed on a postflex-
ion specimen 8.2 mm SL (Table 8). Dorsal and anal
fin formation takes place at the same size as caudal
fin formation; rays are mostly formed on late flex-
ion specimens and fully formed on the 8.2-mm SL
postflexion larva. Pelvic buds are present on all
specimens undergoing notochord flexion except
the smallest (6.2 mm NL), and the full count of six
rays per fin is developed on the 9.6-mm SL post-
flexion specimen. Vertebral counts from two
cleared and stained larvae, 8.6 and 10.0 mm SL,
are 13 + 24.

Distribution . — Fitch (1963) denoted the distribu-
tion of P. coenosus as Alaska to Cape Colnett, Baja
California. Collections of our egg and larval mate-

F|(;i;RE 7. — Transforming specimen of Pleuronichthys roennstis , 10,0 mm.

118

SUMIDA ET AL

EARLY DEVELOPMENT OF SEVEN FLATFISHES

Table 7— Morphometries, in millimeters.

of larvae and a

juveni

le o( Pleuroruchlh

vs coenosus.

(Specimens between dashed 1:

ines are

undergi

oing notochord fl

exion,!

Snout

Body

Body

Caudal

Caudal

Snout

Body

Left

Nolo- to

Head

Shout

Eye

bye

depth at

depth

peduncle

peduncle

to ongin

Stalion

length

eye'

chocd^ anus

length

length

width

height

P base^

at anus^

depth

length

pelvic fin

5902-83 43

3,9 NL

Sym

Sic 1 8

60

016

26

20

30

46

_

5007-127 50

37

Sym

Sic 1 8

68

14

026

22

60

52

_

_

_

5005-120 45

42

Sym

SIC 2 1

80

16

32

24

70

56

_

_

_

OH La Jolla.

Calrl

5 1

Sym

Sir 2 5

1 1

20

40

38

1 1

90

_

—

_

5704-82 47

56

Sym

Sic 26

1 1

26

40

36

90

84

_

_

—

6304-93 40

69

Sym

Sic 3 1

1 6

30

050

46

13

1 3

_

6304-120 70

65

Sym

Sic 3

1 5

28

46

46

1 4

1 6-

^

_

_

5206-90 41

85

Sym

Sic 3 3

1 7

28

64

60

1 6

16

-

-

-

5110-97 30

62

Sym

Ell 2 7

1 4

30

048

42

1 4

1 6-

7207-93 45

7,2

Sym

E II 3 1

1 6

30

056

54

16

1 8-

—

_

1,6

5705-93 27

7,4

Sym

Midll 33

1 8

26

60

054

20-

1 9-

_

_

1,6

5304-85 50

8,3

Sym

Midll 35

1 9

36

60

054

2 2-

2 4-

—

_

17

1941-25 45

7,2

Sym

L II 3 1

1 9

36

58

054

2 r

2 2-

—

1 6

4908-72 56

78

Sym

Lll 4

24

40

68

58

26-

2 7-

-

-

21

5007-90 53

7 1 SL

Sym

Flexed 3 3

20

38

062

056

2 2-

2 3-

62

0,36

20

5004-100 60

8,2

Mtgr

Flexed 3 4

25

40

74

70

3 r

3 4-

98

50

23

6606-70 70

8,8

Migc

Flexed 4

2 7

48

080

74

2 9-

3 3-

84

042

2,6

5304-85 50

9,6

Migc-

Flexed 4 7

30

60

0,92

80

4 2-

4 8-

1 2

052

28

5206-90 41

99

A ovec

Flexed 3 9

32

56

84

080

4 4-

4 9-

1 4

48

28

5407-83 51

10 2

A, over

Flexed 38

34

52

1

84

4 6-

5 r

1 6

52

30

5304-100 29

11 4

Ovec

Flexed 4 3

34

60

1

88

50-

54-

1 6

60

32

Oil CoconacJos

Islands, B C

170

Over

Juv 5 2

4 7

58

1 4

-

7 9-

8 3-

24

10

3.8

'Sym - symmetrical. Migr - migrating. A over - About over

^Str - straight, E fl. • early flexion, f^idfl - midflexion, L fl. - late flexion, Juv juvenile

^Asterisk indicates inclusion of dorsal fin pterygiophores in body depth measurement.

Table 8. — Meristics of larvae and a juvenile of Pleuronichthys coenosus
(Specimens between dashed lines are undergoing notochord flexion.)

Size

Fin rays

Vertebrae

Pectoral

Source

station

(mm)

Stage'

Dorsal

Anal

Caudal

Pelvic

righl/lett

Precaudal Caudal

Total

of count

5902-83 43

3 9 NL

Yolk-sac

LP2

5007-127 50

3 7

Pcell

LP^

5005-120 45

42

Prefl

LP'

Off La Jolla, Calil

5 1

Prell

LP'

5704-82 47

56

Prell

LP'

6304-93 40

69

Prell

LP'

6304-120 70

6,5

Pcell

Forming

Focming

4

LP'

5206-90 41

85

Pcell

Forming

Forming

ca 8

LP;

5110-97 30

62

£11

Focming

Forming

ca 8

LP'

7207-93 45

72

E fl

Focming

Fonning

12

Bud

LP'

5705-93 27

74

Ivlidll

Focming

Forming

12

Bud

LP'

5304-85 50

83

Midfl

Focming

30

12

Bud

LP'

1941-25 45

72

Lfl

ca 55

ca 44

ca 14

Bud

LP'

4908-72 56

78

L ft

ca 60

ca 45

16

Bud

LP'

5007-90 53

7 1 SL

Postfl

ca 70

ca 50

16

Bud

LP'

5004-100 60

8,2

Postfl

74

55

19

ca 4/4

LP'

6606-77 55

8,6

Postfl

72

54

19

ca 5,5

LP'

13 24

37

C&S'

6606-70 70

88

Postfl

-76

50

19

ca 4/4

LP'

5304-85 50

9,6

Postfl

73

ca 52

19

6/6

LP'

5206-90 41

99

PosHI

69

50

19

6/6

LP'

5206-87 45

100

Postfl

71

53

19

—

LP'

13 24

37

C&S^

5407-83 51

102

Postfl

69

49

19

6/6

LP'

5304-100 29

11 4

PosHI

72

50

19

6/6

LP'

Off Coconados

Islands, B C

170

Juv

75

53

19

66

9/9

13 25

38

X-ray

'Prell - preflexion, E fl - early llexion, Midfl - midflexion, L fl - laie flexion. Post f
'LP refers to lunctional larval pectoral fins which have no ossified rays
^Cleared and stained

- poslflexion. Juv - juvenile

rial range from northern California south to Point
Abreojos, Baja California (Figure 8). Our records
extend the range considerably southward for the

species. Larval specimens range widely from
nearshore to about 200 mi offshore, but most oc-
currences are between 50 and 200 mi offshore.

119

FISHERY BULLETIN VOL 77. NO 1

129°

125°

121°

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FU'.URE 8. — Distribution of eggs and larvae of Pleuronichthys
coenosus examined in this study, iTriangles represent eggs,
open circles larvae, and closed circles eggs and larvae.)

Pleiirouichthys verticalis Jordan and

Gilbert (hornxhead turbot)

Figures 9, 10

Literature. — The eggs and two early larvae (3.16
and 3.35 mm) were de.scribed and illustrated by
Budd ( 1940). Four illustrations of larvae, between
4.4 and 8.7 mm SL. are contained in CalCOFI
Atlas No. 23 lAhlstrom and Moser 1975).

Distinguishing characters. — Preflexion and early
flexion larvae of this species are recognizable by
the triangular patches of pigment, one each on the
dorsal and ventral finfold posterior to the anus;
these form late in the yolk-sac stage and persist
through the notochord flexion stage. No other
species of Pleuronichthys develops this distinctive
pigmentation character.

Late flexion and postflexion larvae are distin-
guished by size (i.e., larger than H. guttulata, P.
ritteri. and P. ocellatus, but smaller than P.
coenosus and P. decurrens ), and by sparse pigment
on the head and on the dorsal and anal fin
pterygiophores. This is in sharp contrast to the
heavy pigment in these areas for the other species
discussed.

Newly transformed specimens are difficult to
distinguish from comparable stages of P. ritteri.
However, pigment on the body tends to be mottled
on P. verticalis rather than evenly distributed as
on P. ritteri at this stage. Small juveniles are eas-
ily separable from P. ritteri because P. verticalis
lacks the anterior prolongation of the supratem-
poral branch of the lateral line found on P. ritteri
juveniles.

Pigmentation . — Pigment on yolk-sac and older
preflexion larvae of P. verticalis is heavy on the
head, trunk, and tail and ends anterior to the last
three to five myomeres (Figure 9A, B). As the last
remnant of yolk is absorbed, scattered finfold pig-
ment differentiates into triangular-shaped clus-
ters posterior to the anus, the dorsal patch being
situated slightly anterior of the ventral patch. The
head region below and on each side of the eye is
only sparsely pigmented which is typical of most
early preflexion larvae of several species of
Pleuronichthys. The top of the head to the shoulder
region is unpigmented, a character shared with
preflexion larvae of P. ritteri. Small pigment spots
dot the margin of the tip of the tail, but do not
persist beyond the flexion stage (Figure 9C, D).

120

SUMIDA ET Al..: EARLY DEVELOPMENT OF SEVEN FLATFISHES

Figure 9.— Larval stages of Pleurontchthys verticalis: A. 4.4 mm; B. 6.5 mm, C. 7,1 mm; D. 8.7 mm.

121

FISHERY BULLETIN; VOL. 77, NO, 1

Flexion larvae undergo little change in pigment
pattern from earlier stages. The triangular
patches of finfold pigment are diminished in size
and pigment intensity, but are visible by careful
examination in specimens through notochord flex-
ion.

Following the completion of notochord flexion,
pigment on the tail spreads posteriad leaving only
the caudal peduncle unpigmented (Figure 9D).
The outlying regions of the head and body, par-
ticularly the pterygiophore region, are sparsely
pigmented compared with late larvae of other
Pleuronichthys species and H. guttulata.

Transformed specimens develop heavy pigment
over the body giving them a mottled appearance.
Dark blotches appear along bases of the dorsal and
anal fins (Figure 10).

Morphology. — Larvae of P. verticalts attain a size
intermediate between the large species. P. decur-
rens and P. coenosus, and the smaller P. ritteri. A
specimen with most of its yolk sac remaining is 2.4
mm NL (Table 9). The left eye is beginning to
migrate in a specimen as small as 7.3 mm SL and
transformation is almost complete at 9.2 mm SL.
The smallest available juvenile is 12.2 mm SL,
reared from eggs collected off San Diego, Calif

Gut development follows the course of other
Pleuronichthys. Snout-anus length is about 50'~^ of
body length in preflexion and flexion stages and

then is reduced in postflexion and early juvenile
stages. The gut begins to coil at about 4.0 mm NL
but the free terminal section does not become ver-
tical until at least 5.0 mm NL.

As in the other species, relative head length
increases throughout the larval period and then
decreases at transformation. Snout length and eye
size undergo a gradual relative diminution during
the larval stages; however, relative eye width in-
creases sharply at transformation (Table 5).

Larvae of P. verticalts are intermediate in body
depth when compared with other species of
Pleuronichthys (Table 5l.

Fin and structural development. — P. veriicalis is
the only species for which we could clear and stain
a series of larvae (Tables 10, 11). The sequence of
fin formation was followed more precisely in this
species as was the sequence of ossification of other
structures including the vertebral column, sup-
porting bones of the caudal fin, branchiostegal
rays, gill rakers, and teeth.

The caudal fin begins to form on the under side
of the body a short distance anterior to the tip of
the notochord on specimens of about 5.0 mm NL.
Some caudal rays form before flexion begins (Fig-
ure 11 A). Rays initially form at midcaudal and
those that will be associated with superior hypural
bones differentiate posteriorward, while those
that will be associated with inferior hypural bones

Ficl'KE 10. — Reared transfonning specimen o( Plfurnnu-hthys uerticcilis, 11.0 mm.

122

SUMIDA ET AL,: EARLY DEVELOPMENT OF SEVEN FLATFISHES

Table 9. — Morphometries, in millimeters, of larvae and juveniles of Pleurontchthys verticalis.
(Specimens between dashed lines are undergoing notochord flexion.)

Snout

Body

Body

Caudal

Caudal

Snout

Body

Lett

Noto-

to

Head

Snout

Eye

Eye

depth at

depth

peduncle

peduncle

to orrgin

Station

length

eye'

chord^

anus

lengtti

lenglti

widtfi

tieight

P baseJ

at anus=

depth

length

pelvic fm

7501-120.26

2 4 NL

Sym

Str

1 2

056

10

22

20

022

34

Off La Jolla,

Calif

27

Sym

Str

1 4

54

12

24

22

038

040

—

—

—

SCBS-2-203

30

Sym

Str

1 5

064

16

0.22

20

48

040

_

—

—

7203-103 30

3.8

Sym

Str

20

86

0.20

30

26

070

054

—

—

_

7203-103 30

43

Sym

Str

22

94

024

034

0.32

084

062

—

—

—

7203-103.30

48

Sym

Str

24

10

20

36

032

0.90

070

_

—

_

7501-120 26

5.2

Sym

Str

26

1 3

030

40

034

1.0

80

—

-

—

5708-110.33

50

Sym

Efl

28

1 5

34

0.50

42

1 6-

1 4'

_

_

_

7203-103 30

56

Sym

E fl

27

1 4

0.30

48

46

1 4-

1 2-

_

—

1 5

7503-90 27 6

5.6

Sym

Midfl

29

1 5

30

48

046

18-

18-

_

_

1 4

5510-117 26

59

Sym

Midtl

27

1 6

24

50

52

1 7-

1 6-

—

—

15

7503-120 26

72

Sym

tvlidfl

32

1 9

32

60

056

2 1-

20-

_

_

1 8

5708-110 33

63

Sym.

Ltl

32

1.9

32

60

056

21-

20-

-

-

1 8

7505-120 30

6.5 SL

Sym

Flexed

32

20

0.36

064

60

20-

2 0-

0.54

50

?

SCBS-4-303

7.3

Migr

Flexed

33

26

40

076

68

3 1-

33-

096

40

22

5506-120 45

79

Migr

Flexed

33

29

40

84

068

3 6-

3.6-

1

44

2.4

6606-103 29

83

Migr

Flexed

3.5

27

48

84

68

3.2-

3 5-

1

44

27

6504-137 30

92

l^igr

Flexed

39

29

36

96

084

3 8-

4 2-

1 1

60

2.5

Reared

11

Over

Flexed

40

34

0.36

1 4

1

4 3-

4 4-

I 4

76

27

Reared

122

Over

Juv

4

36

36

1 4

12

5 0-

51-

16

80

32

Reared

15.9

Over

Juv

5.2

43

32

18

1 4

65-

6.6-

22

10

36

Reared

169

Over

Juv

53

45

032

1 8

1 3

66-

69-

23

10

42

Santo Tomas

195

Over

Juv

64

53

008

1 8

1 2

7.8-

84-

2.5

13

47

Bay. B.C

265

Over

Juv

84

70

33

26

2 1

10.9-

114'

33

1 9

65

'Sym. - symmetrical. Migr - migrating

^Str. - straight; E fl - early flexion, fvlidfl - midtlexion; L fl - late flexion, Juv - juvenile

^Asterisk indicates inclusion of dorsal fin pterygiophores in body depth measurement

Table lO. — Meristics of larvae and juveniles of Pleurontchthys verticalis.
(Specimens between dashed lines are undergoing notochord flexion,!

Fin ray

Teeth

Station

Size

(mm)

Stage'

Dorsal

Caudal Pelvic

Pectoral
right left

Gill
rakers

Upper jaw Lower law
R L R L

6609-97.29
7503-90 27 6

6507-107.30
5708-117 26
5708-117 26

5.3 NL

5.6

55

58

57

58

Prefl
Prefl
Prefl,
Prefl
Prefl
Prefl

Forming Forming

Forming Forming

Forming Forming

Forming Forming

Forming Forming

Forming Forming

LP2
LP-'
LP2
LP'
LP^
LP'

5708-117.26

6 1

Efl.

Forming

Forming

8

Bud

LP'

_

—

70

Ltl

43

37

16

Bud

LP'

+ 2

1 2

3

3

6606-97 29

69

Ltl

63

43

18

4,4

LP'

0+3

1 2

3

—

70

PosttI

67

47

19

55

LP'

+ 6

1 3 3

5

6407-83 43

7 1

Postll

64

44

19

3 3

LP'

Not taken

1 4 3

5

5110-100 40

73

Postfl

67

47

19

55

LP'

+ 5

' 6 5

6

6606-97 29

83

Postfl

65

46

19

6/6

LP'

0+5 1

D 5 5

7

6504-137 30

92

PosttI

55

44

19

6/6

LP'

Not taken

Not taken

Reared

11

PosttI

72

49

19

6/6

11 '

2 + 9

Not taken

Reared

122

Juv

72

47

19

6.'6

n.'ii

3+7

Not taken

Reared

15.9

Juv

74

49

20

6/6

12/12

3+8

Not taken

Reared

16.9

Juv

72

48

19

6/6

10/11

3 + 7

Not taken

Santo Tomas

195

Juv

67

47

19

6/6

10/10

2 + 7

Not taken

Bay. BC

26 5

Juv

70

49

19

6,'6

11, '11

3 + 7

Not taken

'Prefl - preflexion, E fl - early flexion, L fl - late flexion: Postfl - postflexton, Juv - juvenile
'LP refers to functional larval pectoral tins which have no ossified rays

differentiate progressively anteriorward. A
number of specimens, 5.3-5.8 mm NL with the
notochord still straight, possess 2 + 2 or 3 + 3
caudal rays. The complete complement of 10 + 9
caudal rays is present on specimens 7.0 mm NL
and larger. Flexion occurs in larvae between 6.1
and 7.0 mm NL (Figure IIB). By the time the

caudal ray complement is fully formed, the rays
are aligned in a terminal position (Figure IIC).
The hypurals are observed as cartilaginous plates
before they ossify. There are two superior and t\vo
inferior hypurals^ in pleuronectid flatfishes. The

^We mclude the "parhvpural" as a hypural bone. In flatfishes it
is a splinter bone without remnant of a haemal arch.

123

FISHERY BULLETIN: VOL 77. NO 1

Table 11.-

-Development of vertebral column, caudal fin rays,

and caudal fin su

pporting bones

in larvae of P/euronjcArtvs wrtica/is.

Body
length

Stage'

Precaudal
vertebrae^

Caudal

vertebrae^

Total
vert 5

Cfin
rays

Ural bones^

n pr

h pr

centra

Ural
centrum

Sup
Upper

hyp
fulid

Inf

hyp.

Stalion

npr

centra

IVIid

Lovirer

Epural

6609-97 29

5 3 NL

Prefl

2 + 2

C

7503-90 27 6

56

Pred

7

T

2*2

—

55

Prefl

4t2

14

14

20-

3 + 3

6507-107 30

58

Prefl

6+3

15

15

24-

3t3

5708-117 26

57

Prefl,

7+5

16

16

28-

3*3

6507-107 30

58

Prefl

7+4

17

17

28-

3i3

5708-117 26

6 1

Efl

13

19

20

33-

4 + 4

c

—

70

Lfl

13

22

22

35-

8 + 8

6606-97 29

69

L fl

13

13

22

22

20

36

9 + 9

C

X

X

X

—

7 0SL

Postfl

13

13

23

23

23

37

10*9

X

X

X

X

6407-83 43

7 1

Poslfl

13

13

22

22

22

36

10 + 9

X

X

X

X

5110-100 40

73

Postfl

13

13

22

22

22

36

10*9

X

X

X

X

X

6606-97 29

83

Postll

13

13

22

22

22

36

10*9

X

X

X

X

X

Reared

110

Postfl

13

13

24

23

23

37

10*9

X

X

X

X

X

Reared

122

Juv

13

13

22

22

22

36

10*9

X

X

X

X

X

Reared

159

Juv

13

13

22

22

22

36

10*10

X

X

X

X

X

Reared

169

Juv

13

13

22

22

22

36

10 + 9

X

X

X

X

X

Santo Tomas

195

Juv

13

13

23

23

23

37

10 + 9

X

X

X

X

X

Bay. B C

26 5

Juv

13

13

23

23

23

37

10 + 9

X

X

X

X

X

'Prefl - preflexion. E fl - early flexion. L fl - lale flexion
^Abbreviations in tieading n pr - neural process, h pr -
'Asterisk indicates incomplete count

Postfl
fiaema

- postflexion. Juv - )uvenile
process, ven - vertebrae;

5up hyp

- Superior hypurals. Inf

hyp

- Inferior hypurals

main superior hypural and the two inferior
hypurals are ossifying in specimens 6.9 mm NL
and larger, the single epural by 7.0 mm SL, and

FlOURE 11, — Development of the caudal fin and supporting
bones in Pleuronichlhys verticalis. A, 5,3 mm NL; B. 6,9 mm
NL; C. 8.3 mm SL. Ossified ural bones are shown in black;
ossified elements of first preural vertebra are stippled, Ural
bones include four hypurals, one epural. and the ural centrum

the small upper superior hypural by 7. .3 mm SL.
Sixteen of the 19 caudal rays are supported by the
four hypural bones, one by the epural and one each
by the neural and haemal spines of the ultimate
vertebra.

The vertebral column begins to ossify at about
the same time rays begin forming in the caudal fin
(Table 11 ). A 5.6-mm NL specimen which has 2 + 2
caudal rays has the first seven haemal processes of

124

SUMIDA ET AL EARLY DEVELOPMENT OF SEVEN ELATFISHES

the caudal group of vertebrae forming. A slightly
more advanced 5. 5-mm NL specimen has 14 oppos-
ing neural and haemal processes of caudal verte-
brae formed as well as the four anteriormost and
last two precaudal neural processes. A neural or
haemal process consists of two portions — a divided
basal portion that forms the neural or haemal arch
ending in the second portion as a terminal spine.
On the 5. 5-mm NL specimen, only the tips of the
neural spines of the caudal group are ossified. Of
the precaudal group, ossification first occurs in the
arched portion of the anterior four neural proces-
ses and on the tips only of the last two precaudal
neural spines. On a 5.8-mm NL specimen with the
first 7 and last 4 precaudal neural processes and 17
pairs of neural and haemal processes in the caudal
group ossifying, all of the neural processes except
those of the 7 anterior precaudal vertebrae were
ossifying initially from both ends, i.e., from the
distal tips of the neural spines and from the basal
portion of the neural arches, with ossification from
both ends proceeding medially (Figure 12A). In a
6.1-mm NL specimen all 13 precaudal neural pro-
cesses and 19 neural and haemal processes in the
caudal group are ossified (Figure 12B). A 7.0-mm

NL late flexion specimen has all neural and
haemal processes ossified except those on the ter-
minal preural vertebra, but no centra are ossified.
A 6.9-mm NL specimen, with all neural and
haemal processes ossifying, has various stages of
vertebral centra ossification with initial ossifica-
tion of centra occurring below the bases of the
neural and haemal arches and then filling in me-
dially; only the two vertebral centra adjacent to
the urostyle lack any ossification; the six verte-
brae immediately forward of these have the best
ossified centra. A 7.0-mm SL specimen has all
centra ossified.

The bases of the dorsal and anal fins are present
on larvae as small as 5.3 mm NL and rays begin to
form by late flexion. Full complements of dorsal
and anal fin rays are present on most postflexion
specimens. Buds of the pelvic fins were first seen
on a 6.1-mm NL specimen, and the complete count
of six rays per fin is developed by 8.3 mm SL.
Pectoral rays form only toward the end of the
transformation stage after the left eye has nearly
completed its migration to the right side.

Branchiostegal rays form progressively an-
teriorward during the period of caudal fin forma-

FinURE 12.— Ossification pattern of the axial skeleton of Plcururuchrhys verticahs: A. 5.8 mm; B 6 1 mm

125

tion between 5.6 and 6.9 mm NL, and the full
count of seven rays per side is present on late
flexion specimens. Gill rakers begin to develop by
late flexion, but the full count is not obtained until
the early juvenile stage. Few teeth form during
the larval period. Only a single tooth is developed
on the right side of the upper jaw in postflexion
larvae, compared with 3-6 on the left side of this
jaw. The disproportion is less marked in the lower
jaw, with 3-5 teeth on the right side compared with
5-7 on the left side.

Distribution . — This species ranges from Point
Reyes, Calif., south to Magdalena Bay, Baja
California, with an isolated population at the
northern end of the Gulf of California (Norman
1934; Fitch 1963). Eggs and larvae are common in
our collections, particularly at inshore stations
located over the continental shelf, with only an
occasional specimen being taken more than 60 mi
from the coast (Figure 13).

Pleitrotiichthys ocellatiis Starks and

Thompson (Gulf turbot)

Figure 14

Literature. — Neither eggs nor larvae have been
described previously.

Distinguishing characters. — This species may
only be confused with P. verticalis or H. guttulata
which cooccur with it in the upper Gulf of Califor-
nia. Larvae may be distinguished from P. ver-
ticalis by the lower total vertebral number of 34 or
35 and pigmentation differences. The larger size of
larvae, lack of pterotic spines, and different pig-
ment pattern separate iifrom H. guttulata . Meris-
tics of the larvae and juveniles, given in Table 12,
are distinctive for the species.

Pigmentation . — Only two postflexion larvae (6.6
mm SL and 7.0 mm SLi were available. Both
specimens are heavily pigmented and somewhat
resemble similar stages of P. verticalis larvae
(Figure 14 vs. Figure 9D). However, smaller sized
larvae of P. ocellatiis are heavier in pigment than
P. verticalis in regions of the head and dorsal and
anal fin pterygiophores. Only the margin of the
opercle, otic region, pectoral fin. and caudal
peduncle remain unpigmented.

Morphology. — Larvae of P. occllalus are inter-
mediate in size between comparable stages of P.

126

129°

40'

35'

30'

25"

20=

FISHERY BULLETIN VOL. 77. NO 1
125° 121°

-r

7^

/"

s^CAPE
MENDOCINO

vSAN ,

FRANCISCO

cS^

SAN

"DIEGO

44°

40°

35°

30°

25°

115°

106°

Fli'rl'RE 13. — Distribution of eggs and lar\*ae of Pleuronichthys
verticalis examined in this study. (Triangles represent eggs,
open circles larvae, and closed circles eggs and larvae.)

rilterl and P. verticalis (Table 13). It is the most
slender-bodied species having the smallest body
depth ratios in the po.stflexion larval stage within
its genus (Table 5).

SUMIDA ET AL . EARLY DEVELOPMENT OF SEVEN FLATFISHES

jCr

3— J^

■^ ^ — -■'- ^■" o'Xi-Vv ^V'." ■'"■"-" ^"'' ^ -i ^"' C^'--^ '*■■■'' ' ' '

"^-iili/i:^.{i!iij:i::,, ;v ,^; ;%

Figure I'i.—Pleuronichthvs ocellatus larva, 7.0 mm.

Table 12. — Meristics of larvae and juveniles of Pleuronichthys ocellatus.

Size
(mm)

Stage'

Fin rays

Vertebrae

Station

Dorsal

Anal

Caudal

Pelvic

Pectoral
rig tit/left

Precaudal Caudal

Total

Source
of count

5604-111 G 14

6 6SL

Postll

65

49

19

ca 4/4

LP^

5604109G25

70

Postfl

73

50

19

ca. 3/3

LP'

Uppef Gull 0l

192

Juv

64

46

19

6/6

10/11

12

22

34

X-ray

Calilornia

22

Juv

73

49

19

6/6

10/10

12

24

36

X-ray

24

Juv

67

48

19

6'6

— /11

12

22

34

X-ray

24 5

Juv

71

51

19

6; 6

ii;io

12

23

35

X-ray

25

Juv

70

50

19

6/6

11/10

12

22

34

X-ray

255

Juv

68

46

19

6/6

10/10

12

23

35

X-ray

'Postfl postflexion. Juv - juvenile

^LP refers to functional larval pectoral fins

whicfi fiave no ossified rays

Table 13

—Morphometries,

in millimeters,

of larvae and juveni!

es of Pleu

ronichth

vs ocellatus.

Station

Body
lengtt

Left
eye'

Noto-
cfiord^

Snout

to
anus

Head
length

Snou
lengtti

Eye
<vidtfi

Eye
fieight

Body
deptfi at
Phase

Body
deptfi
at anus

Caudal

peduncle

depth

Caudal

peduncle

length

Snout
to origin
pelvic lin

5604-111 G 14

6 6 SL Sym

Flexed

32

20

30

54

56

22

22

50

0,40

19

5604-109 G 25

70

Sym

Flexed

3 3

2 1

40

62

56

23

23

52

50

2,1

Upper Gulf of

192

Over

Juv

70

57

083

1 8

—

82

90

24

1.2

5,0

California

22

Over

Juv

70

62

91

1 9

—

94

9,8

28

1 4

5,2

24

Over

Juv

7 7

65

91

2 1

—

94

10,2

28

1 4

57

24 5

Over

Juv

74

68

1 1

23

—

105

110

32

1 5

5,5

25

Over

Juv

7 5

6 7

83

25

—

104

11 2

32

17

5,7

255

Over

Juv

85

68

91

23

—

10,7

11 7

31

1,8

6,0

'Sym, - symmetrical,
'Juv, - juvenile

Distribution. — This species is restricted to the
northern half of the Gulf of California (Norman
1934; Fitch 1963). Larvae were collected at two
stations in the upper Gulf

Pleuronichthys ritteri Starks and

Morris (spotted turbot)

Figures 15-17

Literature. — The egg of P. ritteri was described by
Orton and Limbaugh (1953) and illustrated by
White ( 1977). Larvae of this species have not been
described previously.

Distinguishing characters . — Larval stages of this

species may be confused with P. vcrticalis and H.
guttulata. Characters of preflexion and flexion
larvae which separate it from P. verticalis include
the lack of triangular clusters of pigment on the
finfold, less pigment on the tail with 8 or 9 unpig-
mented myomeres compared with 3-5 in P. ver-
ticalis, and a more robust body. Postflexion larvae
are more heavily pigmented, particularly on the
dorsal and anal fin pterygiophores, and are small-
er than comparable stages of P. verticalis. Distin-
guishing characters for newly transformed and
early juvenile stages have been discussed earlier
under P. verticalis.

Characters for distinguishing yolk-sac larvae of
P. ritteri from H. guttulata include the presence of

127

FISHERY BULLETIN VOL

. NO 1

pigment on the finfolds of P. ritteri, a smaller oil
globule (average 0.10 vs. 0.14 mm), lack of pig-
ment on the oil globule, and presence of pigment
ventrally near the tip of the notochord. Distinctive
characters of preflexion and flexion larvae of P.
ritteri include the lack of pterotic spines on the
head which is more rounded than on preflexion H.
guttulata, the lack of pigment from the top of the
head posteriorly to the nape, a more robust head
and trunk (compare Figure 15D with Figure 19D),
and the presence of small pigment spots on the
pectoral fin blade along its margin or base. Post-
flexion and early transforming specimens can be
distinguished by a deeper and shorter caudal
peduncle, a more robust body, and the origin of the
dorsal fin on the future blind side of the head
instead of on the medial line of the head as found in
H. guttulata.

Pigmentation. — Yolk-sac larvae are heavily pig-
mented with the exception of the last 8 or 9 myo-
meres. Pigment is also scattered on the remnant of
the yolk sac, on the dorsal and ventral finfolds, and
ventrally on the tail near the tip of the notochord
(Figure 15A). Except for the appearance of pig-
ment along the margins of the pectoral fin blade,
no significant changes in pigmentation occur in
early preflexion larvae of ca. 3.0 mm NL (Figure
15B).

By 4.0 mm NL, pigment found earlier along the
top of the head posterior to the nape is lost, leaving
an unpigmented streak which persists until flex-
ion of the notochord is complete at 5.5 mm NL
(Figures 15C, D; 16A, B). Ventral pigment is simi-
larly lost on the abdominal region, resulting in an
unpigmented lower abdomen in late preflexion
and flexion specimens. Marginal pectoral fin pig-
ment present on larvae to about 3.3 mm NL,
changes to small, discrete spots on the fin mem-
brane along its base. These melanophores persist
through postflexion larvae until the pectoral fin
differentiates into a small, rayed fin by ca. 10.0
mm SL (Figures 16C, 17).

Pigment on the tail extends posteriad the same
distance in flexion larvae as in preflexion larvae,
but in postflexion larvae the tail pigment fills in
posteriorly to the terminal dorsal and anal fin
rays. In later postflexion and transformation
stages, the head, trunk, and tail, except the caudal
peduncle, are completely covered with pigment
which extends over the dorsal and anal fin
pterygiophores (Figures 16C, 17).

At 10.0 mm SL, a dark circular blotch of pig-
ment develops on the middle section of the body,
with a heavy band of pigment at the posterior
extreme of body pigment. Several triangular
patches are clustered on the dorsal and anal fin
rays above the pterygiophores. The caudal pedun-
cle area remains unpigmented (Figure 17).

Morphology. — Larvae of P. ritteri are the smallest
among species of Pleuronichthys in comparable
stages of development. Our smallest .specimen has
a large yolk sac and is 2.1 mm NL (Figure 15A).
The oil globule is positioned posteriorly in the yolk
mass and measures 0.11 mm in diameter. The left
eye begins to migrate at about 6.0 mm SL and
migration of the eye is completed before 10.0 mm
SL (Table 14). The smallest available juvenile was
12.7 mm SL.

The gut develops as in other Pleuronichthyti but
coiling begins earlier, at about 3.0 mm NL, and the
terminal section of the gut is in a vertical position
in most specimens >4.0 mm NL.

The head is relatively larger in preflexion lar-
vae of P. ritteri than in the other species (Table 5).
Relative head length increases throughout the
larval period, then is moderately reduced at trans-
formation. Mean relative snout length increases
in P. ritteri larvae undergoing notochord flexion
and decreases during subsequent .stages, but in
other species ofPleuronichthys it decreases during
all major phases of larval development. Relative
eye size is largest in preflexion larvae, becomes
reduced in later larval stages, and increases at
transformation.

The early larvae of P. ritteri are the deepest
bodied species of Pleuronichthys. Mean relative
body depth measured at the base of the pectoral fin
is greater during preflexion and flexion stages of
the notochord than in any other species. In post-
flexion larvae, however, mean relative body depth
is markedly less than in P. decurrens and about
equal to that in P. coenosu.'i and P. vertieali.s (Table
5).

Fm and axial skeleton formation. — Early caudal
formation involving thickening in the hypural
area of the developing caudal fin occurs on
larvae 4.3-5.1 mm NL (Table 15). Caudal rays are
forming on larvae as small as 4.5 mm NL, with a
simultaneous initiation of flexion of the notochord.
Specimens between 4.5 and 5.6 mm NL undergo
notochord flexion. Our smallest specimen with a
fully flexed notochord is 5.3 mm SL. The full

128

SUMIDA ET AL.. EARLY DEVELOPMENT OF SEVEN FLATFISHES

FlClIRE 15.— Reared larval stages oi Pleuronichthys ritleri. A
2.1 mm; B. 3.0 mm; C. 4.2 mm; D. 4.2 mm. dorsal view.

129

FISHERY BULLETIN VOL, 77, NO

Figure 16— Lan-al stages of P/eumnichlhys ntleri: A. 5.6 mm; B. 5.5 mm; C. 6.4 mm.

130

SUMIDA ET AL. EARLY DEVELOPMENT OF SEVEN FLATFISHES

Figure 17. — Transforming specimen o( Pleurontchthys ntteri, 10.0 mm.

Table 14. — Morphometries, m millimeters, of larvae and juveniles oi Pleuronichthys ntteri.
(Specimens between dashed lines are undergoing notochord flexion.)

Snout

Body

Body

Caudal

Caudal

Snout

Body

Left

Noto-

to

Head

Snout

Eye

Eye

deptti at

deptti

peduncle

peduncle to

to origin

station

lengthi

eye'

ctiord'

anus

lengtti

lengtti

widtti

fieigtit

P base>

at anus^

deptti

lengtti

pelvic fin

Oft La Jolla,

Calit

2 1 NL

Sym

Sir

1 2

50

10

024

0.20

20

38

—

—

—

30

Sym

Str

1 4

60

12

26

22

42

42

—

—

—

7412-123 36

33

Sym

Str

1 6

80

14

28

024

78

58

—

—

—

Off La Jolla

42

Sym

Str

22

1

18

40

32

96

86

—

—

—

5709-117 26

43

Sym

Str

2 1

1 1

020

40

36

1 2

12-

—

—

—

7207-123 36

4 4

Sym

Sir

2 1

1 1

024

34

32

1

09

—

—

—

6204-120 25

50

Sym

Str

22

1 2

20

38

38

1 2

1 r

—

—

—

5708-12025

51

Sym

Str

25

14

24

046

0,40

1 8-

1 7'

—

—

1,3

6507-120 35

45

Sym

E fl

23

1 4

32

44

42

1 6-

1 6-

1 2

5506-120 40

48

Sym

Ell

23

1 4

28

40

038

1 5-

1 7-

—

—

14

5510-11726

55

Sym

Midll

2 7

1 2

34

52

48

2 0-

1 9-

—

—

16

7501-120 25

56

Sym

Midfl

2 7

1 5

26

46

40

1 8-

1 5-

—

—

1 4

5112-120 35

5 3SL

Sym

Flexed

27

1 7

30

52

52

2 2-

2 2-

50

36

1 4

5802-137 23

60

f^igr

Flexed

29

20

32

60

54

2 4-

2 7-

66

30

1 8

Oft La Jolla

64

fvligr

Flexed

26

22

040

064

60

2 5-

2 7-

76

38

20

Sebastian Viscaino

Bay, B C

75

A over

Flexed

30

26

40

80

64

2 9-

3 0-

1

48

27

7501-120 22 4

85

A over

Flexed

28

27

40

86

7

3 6-

3 6-

1 1

44

23

Off La Jolla

100

Over

Flexed

31

31

48

1

80

4 2-

4 2-

1 4

60

26

Reared

127

Over

Juv

42

38

36

1 4

1

5 1-

5 4-

1 4

76

34

Reared

150

Over

Juv

45

42

48

1 6

1 2

5 9-

6 1-

1 8

1

39

Reared

167

Over

Juv

52

4 7

48

1 8

1 4

6 2-

6 4-

20

1 1

42

Off San Juanico,

B,C

23

Over

Juv

72

68

0.83

22

9

9 7-

9 7-

26

1,2

58

'Sym - symmetrical, Migr - migrating A over - About over

2Str - straigtit, E fl - early flexion, fvlidtl - midflexion, Juv - juvenile

^Asterisk indicates inclusion of dorsal fin pterygiophores in body deptti measurement

caudal count of 19 rays was observed on a 6.0-nim
SL postflexion specimen.

Dorsal and anal fin bases are forming in the
finfold on larvae 4.3 mm NL, and the full comple-

ment of rays develops by 6.0 mm SL. Pelvic fin
buds are evident during early caudal formation
but rays are first observed on a 6.0-mm specimen.
Pectoral rays were fully formed on a 10.0-mm

131

FISHERY BULLETIN VOL 77. NO. 1

Table 15. — Meristics of larvae and juveniles o( Pleuronichthys ritteri.
(Specimens between dashed lines are undergoing notochord flexion.)

Fin rays

Size

Pectoral

station

(mm)

Stage'

Dorsal

Anal

Caudal

Pelvic

right/left

Off La Jolla.

Calif.

2 1 NL

Yolk-sac

LP'

30

Prell

LP=

7412-123 36

33

Prell

LP=

Ofl La Jolla

42

Prefl

LP'

5709-117.26

43

Prefl

Forming

Forming

Forming

LP'

7207-23 36

44

Prell

Forming

Forming

Forming

LP'

6204-120.25

50

Prefl

Forming

Forming

Forming

LP'

5708-120 25

5 1

Prell

Forming

Forming

Forming

Bud

LP'

nghl/left Precaudal Caudal Total

Source
of count

6507-120 35

45

E fl

Forming

Forming

ca 6

Bud

LP'

5506-120 40

48

Efl

Forming

Forming

ca 4

Bud

LP'

5510-117 26

55

lulidfl

Forming

Forming

ca 8

Bud

LP'

7501-120 25

56

Midfl

Forming

Forming

ca 8

Bud

LP'

5112-120 35

5 3SL

Postfl

ca 60

ca 45

16

Bud

LP'

5802-137 23

60

Postfl

72

49

19

6;6

LP'

Oil La Jolla

64

Postfl

65

45

19

6/6

LP'

Sebastian Visca

no

Bay, B C

75

Postfl

70

48

19

6/6

LP'

7501-120 22 4

85

Postfl

69

51

19

6/6

LP'

Off La Jolla

100

Postfl

68

47

19

6/6

9/9

12

23

35

X-ray

Reared

12 7

Juv

69

47

19

6/6

10/11

12

23

35

X-ray

Reared

150

Juv

64

44

19

6/6

10/11

12

23

35

X-ray

Reared

16 7

Juv

65

44

19

6/6

11/11

12

22

34

X-ray

Off San Juanico

BC

23

Juv

68

49

Damaged

6/6

9/9

12

23

35

X-ray

'Prefl - preflexion, E fl - early flexion, fwlidfl - midflexion, Postfl - postflexion; Juv - juvenile
'LP refers to functional larval pectoral fins wfiicti tiave no ossified rays

larva. A radiograph of this specimen showed 12
precaudal and 23 caudal vertebrae, the typical
count for this species.

Distribution. — This species ranges from Morro
Bay. Calif., to Magdalena Bay, Baja California
(Fitch 1963; Miller and Lea 1972; Fierstine et al.
1973). Our egg and larval material, which was
collected between .southern California and Mag-
dalena Bay, Baja California, shows a markedly
coastal, inshore distribution for P. ritteri, with a
majority of collections made over or near the con-
tinental shelf (Figure 18).

Hypsopsettii giittnlata Girard

(diamond turbot)

Figures 19-22

Literature. — Orton and Limbaugh (1953) and
Orton (1953) briefly described the eggs of//, gut-
tiilala. Eldridge (1975) described and illustrated
larvae of this species, and noted the average size of
its egg and oil globule. Although the larval series
is quite well described in Eldridge (1975) (except
for the omission of the pterotic spine on the head),
we are including information about distinguish-
ing characters, pigmentation, etc. to facilitate
identification.

Distinguishing characters. — Larvae of H. gut-
tulata are distinguishable from species of
Pleuronichthys, except for P. ritteri, by their lower
total vertebral number, by attaining comparable
stages of development at smaller sizes, and by the
presence of a pterotic spine on each side of the head
in yolk-sac larvae to midflexion larvae. In the
genus Pleuronichthys, only P. decurrens develops
pterotic spines. (See Distinguishing characters for
P. decurrens. )

The only species with which larval H. guttulata
may be confused is P. ritteri because of its rela-
tively small size and somewhat similar pigment
pattern. (See Distinguishing characters for
separating larvae of the two species discussed
under P. ritteri .)

Pigmentation. — Yolk-sac larvae are heavily pig-
mented on the head, trunk, and for a short dis-
tance on the tail, with the posteriormost 9 or 10
myomeres remaining unpigmented (Figure 19A).
Pigment spots are scattered over the ventral and
posterior surfaces of the yolk sac and oil globule,
and over the terminus of the gut.

Preflexion larvae show little change in pigment
pattern. One or two melanophores develop on the
pectoral fin base. The isthmus has a line of pig-
ment spots, and the entire abdominal area is cov-
ered with pigment (Figure 19B.).

132

SUMIDA ET AL- EARLY DEVELOPMENT OF SEVEN FLATFISHES
129° 125° 121°

40'

35'

30'

25'

20°

/^

T-

1-

-r

-r

/

/^

V

T"

MENDOCINO

MAGDflLENA _

40°

35°

30°

25°

115°

110°

106°

Figure 18. — Distribution of eggs and larvae of Pleuronichthys
ritteri examined in this study. (Triangles represent eggs, open
circles larvae, and closed circles eggs and larvae. t

At the initiation of dorsal and anal fin forma-
tion, the tail pigment spreads out dorsally and
ventrally onto the finfold, resulting in conspicuous

dark mounds of pigment opposing each other in
the area between the body and the dorsal and anal
fin bases (Figure 19C). The tops of the head, nape,
and shoulder area are pigmented in contrast to P.
ritteri. which has an unpigmented streak dorsally
(Figure 19D). Flexion, postflexion, and early
transforming specimens maintain the earlier
pigment pattern and the only obvious change is a
slight posteriad extension of trunk pigment, leav-
ing 5 or 6 unpigmented myomeres posteriorly
compared with 9 or 10 in earlier stages (Figure
20). The base of the pectoral fin acquires more
pigment spots in postflexion larvae, and pigment
on the head similarly increases in density (Figure
20B).

Preserved small juveniles are brownish-black
with numerous small, dark spots scattered over
the body and pterygiophores, giving them a mot-
tled appearance (Figure 21).

Morphology. — Our smallest yolk-sac larva is 2.2
mm NL and has a posteriorly positioned oil
globule 0.14 mm in diameter (Figure 19A). The
left eye is beginning to migrate in a specimen 4.4
mm SL and is complete in a 7.3-mm SL larva
(Table 16). The smallest available juvenile was
11.2 mm SL.

A major distinguishing feature of Hypf^opxetta
larvae is the presence of a pterotic spine on each
side of the head. The spines are present on the
smallest yolk-sac larva and are prominent in most
preflexion larvae. The spines begin to regress on
late preflexion larvae, and are totally regressed in
late flexion specimens. In P. deciirrens the spines
are well developed throughout the larval period
and begin to regress late in the postflexion stage.

Although mean relative body depth of H. gut-
tiilata larvae increases with development, it is
slightly less in postflexion specimens than in any
species of Pleuronichthys , except P. ocellatiis (Ta-
ble 5). In newly transformed juveniles, however,
relative body depth is greater than in any species
oi Pleuronichthys. As a juvenile. H. guttulata as-
sumes a diamond-shaped body form.

Relative body width is useful to separate Hyp-
sopsetta larvae from those of P. ritteri. As shown in
Figures 15D and 19D, larvae of Hypsopsetta have
narrower bodies.

Fin formation. — The caudal fin forms on larvae
between 4.0 and 5.2 mm NL and is complete on
some specimens as small as 4.4 mm (Table 17). The
dorsal and anal fins form simultaneously with the

133

FISHERY BULLETIN VOL 77. NO 1

FIGURE 19.— Larva] stages o[ Hypxopseltu guttulata: A. 2.2
mm; B. 2.6 mm; C. 4.6 mm; D. 4.6 mm, dorsal view.

134

SUMIDA ET AL : EARLY DEVELOPMENT OF SEVEN FLATFISHES

Figure 20.— Larval stages of Hypsopsetta guttulala: A. 5.9 mm; B. 6.6 mm.

caudal and are complete, or nearly so, on all post-
flexion specimens (4.4-8.8 mm SL). Pelvic fins are
late in forming compared with their developmen-
tal pattern in Pieiironichlhyn larvae. Pelvic buds
can be observed only after notochord flexion has
been completed, and rays are first evident on the
6.6-mm SL specimen.

Distribution. — Hypsopsetta guttulata ranges from
Cape Mendocino. Calif., to Magdalena Bay, Baja
California, with an isolated population in the
upper Gulf of California (Norman 1934; Fitch
1963). Egg and larval material examined by us
was collected in bays along the coast, or at Cal-
COFI stations located over the continental shelf, a
pattern of distribution similar to the habitat of P.
ritteri (Figure 22).

Hippoglossitia stoma ta Eigentnann

and Eigenmann (bigmouth sdIc)

Figure 23

Literature. — There is no published account of eggs
and larvae of this species. However, Leonard
( 197 1 ) described a larval series oiH. oblonga from
the western North Atlantic. Earlier, Agassiz and
Whitman ( 1885) and Miller and Marak 1 1962) de-
scribed the eggs and early-stage larvae of//, ob-
longa. Miller and Marak reported the egg size
range as 0.91-1.12 mm (average 1.04 mm) with an
oil globule diameter ofca. 0.1 7 mm. The larval size
at hatching was 2.7-3.2 mm.

Distinguishing characters. — Preflexion larvae of
H. stomata may be confused with early larvae of P.

135

FISHERY BULLETIN: VOL. 77. NO 1

m^iCfei,.

^^^-:^^ij,n

•%.?.:U^<^---^^ •■-.5 '•^^«;i^

^:

.^^
..*,

Figure 21, — Early juvenile o{ Hypsopsetta guttulata. 1.3.2 mm.

coenosus and P. uerticalts due to similarities in
size and pigmentation of the larvae, and the pres-
ence of pigment on the finfold dorsally and ven-
trally, posterior to the anus. Characters of H.
stomata larvae which distinguish them from
preflexionP. coenosus larvae include the presence
of a pigment bar through the eye, heavy pigment
on both sides of the pectoral fin base and a sprinkl-
ing of pigment on the pectoral blade, a more slen-
der, elongate body, and a significantly smaller
patch of dorsal finfold pigment. The same charac-
ters help to distinguish H. storjiata from P. ver-
ticalis. except for the finfold pigmentation.
Pleuronichthys verticalis has small, triangular-
shaped pigment patches whereas H. stomata has a
small rounded pigment cluster on the dorsal
finfold and a broad patch on the ventral finfold.
Larvae of P. verticalis are also smaller than H.
stomata at similar developmental stages.

Larvae in the flexion stage and larger are read-
ily separable from Pleuronichthys by the preoper-
cular spines and development of several elongated
dorsal rays in the anteriormost part of the dorsal
fin. These do not develop on larval Pleuronichthys
or Hypsopsetta.

L36

Pigmentation. — Yolk-sac larvae (ca. 3.7 mmi are
heavily pigmented on the trunk and tail except for
the posteriormost part of the tail which is pig-
mented with several small spots dorsally and ven-
trally (Figure 23A). The upper head and abdomi-
nal region have scattered pigment, with a more
concentrated bar of pigment on each side of the
eye. Both sides of the pectoral fin base are con-
spicuously pigmented. Finfold pigment consists of
a small, rounded patch at the edge of the dorsal
finfold, and a broad patch on the ventral finfold,
both situated posterior to the anus near the mid-
point between the anus and tip of the tail (Figure
23Ai.

Preflexion larvae, 4. 1-7.0 mm NL, undergo little
change in pigmentation except to augment pig-
ment in areas of the pectoral fin, abdominal re-
gion, and top of the head (Figure 23Bi.

On larvae forming the dorsal and anal fins, the
dorsal finfold pigment spreads to include the area
between the fin rudiments and body margin, and
the ventral finfold pigment spreads both an-
teriorly and posteriorly (Figure 23C). Pigment on
the pectoral fin base intensifies and also extends
out onto the fin blade.

SUMIDA ET AL.; EARLY DEVELOPMENT OF SEVEN FLATFISHES

Table 16. — Morphometries, in millimeters, of larvae and juveniles of Hypsopselta guttulata.
(Specimens between dashed lines are undergoing notochord flexion. I

Snout

Body

Body

Caudal

Caudal

Snout

Body

Letl

Noto-

to

Head

Snout

Eye

Eye

depth at

depth

peduncle

peduncle

to ongin

Station

length

eye'

chord'

anus

length

length

width

height

P base^

at anus^

depth

length

pelvic fin

San Diego Bay

2 2 NL

Sym

Sir

1 1

38

08

17

13

18

28

_

King Harbor,

Calif

23

Sym

Sir

1 1

46

12

20

017

18

34

_

7501-120 25

28

Sym

Sir

1 4

068

012

26

22

62

052

_

_

7501-120 29

33

Sym

Sir

1 7

82

20

30

24

82

72

_

San Diego Bay

36

Sym

Sit

1 8

084

16

32

28

78

066

_

_

_

San Diego Bay

40

Sym

Sir

20

88

20

36

030

88

084

_

7412-127 32 6

4 4

Sym

Sic

22

90

20

037

32

1

092

-

-

-

7412-127 32 6

46

Sym

Ell

23

1 2

24

38

32

1 1

1

7501-120.224

49

Sym

Efl

24

1 3

22

40

36

1 2

1 1

—

_

_

7501-120.29

51

Sym

E fl

25

1 2

22

0,40

036

11

1 1

_

_

King Harbor

52

Sym

Lfl

24

1 4

28

44

0.42

12

12

—

-

-

L A Harbor

Calif

4 4 SL

Migr

Flexed

22

1 6

30

48

42

1 8-

1 9-

40

40

1 4

La Jolla. Calif

48

Migr

Flexed

22

1 5

30

48

40

1 6-

1 T

40

36

1 4

San Diego Bay

54

Migr

Flexed

23

18

34

52

40

1 8-

1 9-

42

42

1 6

7501-120,22.7

59

Sym

Flexed

31

1 8

32

50

046

2 0-

2 2-

44

48

1 9

7501-120,24

66

Migf

Flexed

32

2 1

40

62

052

2 3-

2 4-

50

60

20

Reared

73

Over

Flexed

29

25

40

090

70

3 3-

3 5-

76

064

2 1

Reared

79

Over

Flexed

29

27

44

92

68

3 6-

3 8-

86

70

2 1

Reared

8,8

Over

Flexed

36

30

48

1

076

4 1-

4 2-

096

068

26

Reared

112

Over

Juv

4 2

37

50

1 4

1 1

5 7-

6 0-

1 4

1

33

Richardson Bay

129

Over

Juv

45

43

52

1 2

92

7 0-

7 0-

1 5

10

36

Calif

132

Over

Juv

48

43

75

1 3

1 1

6 7-

7 r

1 4

1

36

140

Over

Juv

50

47

75

1 4

1 2

7 5-

77-

1 6

1 2

38

145

Over

Juv

52

48

72

1 4

1

7 7-

7 9-

1 8

88

4 1

184

Over

Juv

64

58

80

1 7

1 4

10 0-

10 5-

2 1

1 4

5 1

'Sym symmetrical, Migr - migrating

^Str - straight; E (I - early flexion, L Tl - late flexion. Juv )uvenile

^Asterisk indicates inclusion of dorsal tin pterygioptiores m body depth measurement

Table 17. — Menstics of larvae and juveniles of Hypsopsetta guttulata.
(Specimens between dashed lines are undergoing notochord flexion.)

Size

Fin rays

Verlebrap

Pectoral

station

(mm)

Stage'

Dorsal

Anal

Caudal

Pelvic

right/left

Precaudal

Caudal

Total

of count

7501-120 25

2 8 NL

Prefl

LP'

7501-120 29

33

Prefl

LP'

San Diego Bay

3.6

Prefl

LP'

San Dieqo Bay

40

Prefl

Forming

Forming

Forming

LP'

7412-127 32 6

4 4

Prefl

Forming

Forming

6

LP'

7412-127 32 6

45

Efl

Forming

Forming

8

LP'

7501-120 22 4

49

Ell

Forming

Forming

6

LP'

7501-120 29

51

E II

Forming

Forming

4

LP'

King Harbor, Calif

52

L fl

ca 50

ca 35

15

LP'

LA Harbor, Calif

4 4 SL

Postfl

67

47

19

Bud

LP'

Off La Jolla, Calif

48

Postfl

66

49

19

Bud

LP'

San Diego Bay

54

PosHI

73

45

19

Bud

LP'

7501-120 22 7

5.9

Postfl

73

46

19

Bud

LP'

7501-120 24

66

PosHI

69

50

19

6 6

LP'

Reared

7 3

Postfl

. 68

47

19

6,6

11 11

1 1

23

34

X-ray

Reared

79

Postfl

67

51

20

6,6

12 12

12

23

35

X-ray

Reared

88

Postfl

72

50

19

6;6

13/13

12

23

35

X-ray

Reared

112

Juv

73

48

19

4/6

12/12

12

22

34

X-ray

Richardson Bay, Calif

129

Juv

66

48

19

5/6

12/11

12

23

35

X-ray

132

Juv

74

53

19

6/6

11/11

12

23

35

X-ray

140

Juv

78

55

19

6/6

11/11

12

23

35

X-ray

14 5

Juv

71

51

19

6/6

12/12

12

23

35

X-ray

184

Juv

68

51

19

6/6

11/12

12

23

35

X-ray

'Prefl - preflexion, E fl - early flexion, L fl - late flexion, Postfl - postflexion, Juv
'LP refers to functional larval pectoral fins which have no ossified rays

juvenile

Postflexion and early transforming specimens
are less heavily pigmented than earlier stage lar-
vae, with a noticeable diminution of pigment on
the dorsal area of the head and body ( Figure 23D ) .

Morphology. — Larvae of H. stomata are closest to
P. coenosus in size at hatching, notochord flexion,
and transformation (Table 18). A specimen 3.7
mm NL has a moderate amount of yolk remaining.

137

FISHERY BULLETIN: VOL. 77. NO 1

129°

125°

121°

40'

35<

30'

25'

20'

40°

MAGDALENA

115°

Figure 22. — Distribution of eggs and larvae of Hypsopsetta gut-
tulata examined in this study. (Open circles represent larvae,
closed circles eggs and larvae.)

The right eye is beginning to migrate in a speci-
men 9.1 mm SL and transformation is almost
complete at 11.7 mm SL.

In early preflexion larvae of Hippoglossina, the
gut is shaped like that in Pleuronichthys larvae;
however, coiling begins at about 4.5 mm NL and
the gut assumes a more compact shape than in
Pleuronichthys. This is reflected in the relatively
shorter snout-anus length. Mean relative snout-
anus length remains at about 4CK7c of the body
length throughout the larval period, in contrast to
Pleuronichthys larvae in which there is a gradual
decrease in relative gut length during larval de-
velopment (Table 5). In juveniles, however, there
is a decrease in snout-anus length to about 33% of
body length, a value comparable with that in
Pleuronichthys juveniles.

The head is similar in size and shape to that in
Pleuronichthys. Relative head length increases
gradually during larval development. The same is
true for relative snout length and is thus opposite
to the condition in Pleuronichthys; however, it de-
creases somewhat in juveniles. Relative eye width
undergoes a moderate diminution during larval
development as in Pleuronichthys, but increases
moderately in juveniles.

Small preopercular spines develop on larvae
from ca. 5.5 mm NL, become most conspicuous on
flexion stage larvae, and undergo resorption dur-
ing transformation from 9.5 mm SL. This spina-
tion is distinctive of H. stomata when compared
with Pleuronichthys and Hypsopsetta.

Larvae oi Hippoglossina have a slender appear-
ance compared with .some of the deeper bodied
species of Pleuronichthys. Body depth at the anus
is comparatively small in preflexion larvae and
remains so in flexion and postflexion larvae and
early juveniles (Table 5).

As in Hypsop.'ietta, the caudal peduncle is longer
and more slender than in Pleuronichthys, except
for P. ocellatus postflexion larvae.

Fin formation. — Larvae of Hippoglossina stomata
are comparable with those of P. coenosus with
regard to size at which the caudal fin develops.
Caudal fin formation occurs between 6.2 and 8.8
mm NL (Table 19). Although about six caudal rays
are formed on a 7.0-mm NL specimen with a
straight notochord, all other specimens with
caudal rays have the notochord flexing. The
smallest, fully flexed specimen is 7.1 mm SL.
Postflexion specimens <9.0 mm SL lack the full
complement of I8V2 caudal rays. The ural bones
supporting the caudal rays are made up of two
superior and two inferior hypurals; there is no
epural. The lack of an epural bone is a specific

138

SUMIDA ET AL.i EARLY DEVELOPMENT OF SEVEN FLATFISHES

Figure 23.— Larval stages of Hippog/ossma slomala: A. 3.8 mm; B. 4.8 mm; C. 8.3 mm; D. 8.6 mm.

139

FISHERY BULLETIN: VOL. 77, NO 1

Table 18. — Morphometries, in millimeters, of larvae o( Hippoglossina stomata.
(Specimens between dashed lines are undergoing notochord flexion.)

Snout

Body

Body

Caudal

Caudal

Snout

Body

Lett

Noto-

to

Head

Snout

Eye

Eye

depth at

depth

peduncle

peduncle

to origin

Stalion

length

eye'

chofd'

anus

length

length

width

height

P base^

at anus^

depth

length

pelvic tin

720M1735

3 7NL

Sym

Sir

1 4

0,64

0,10

28

0,21

50

40

_

_

_

7412-103 29

4 1

Sym

Sir

1 8

0,72

007

24

24

48

36

—

—

—

7412.88,5.31

4.8

Sym

Sir

2

10

24

36

028

0%

068

—

—

—

5801-117 35

5.2

Sym

Sir

22

1 2

24

48

36

1 2

082

—

—

—

6310-93 28

6.2

Sym

Str

22

1 3

026

42

036

12

0,92

—

—

—

6605-123 37

64

Sym

Str

22

1 3

24

44

36

1 4'

1

—

—

—

5910-117 30

6.2

Sym

Str

28

1 6

30

054

42

2 1-

1 3

—

—

—

6706-110 50

70

Sym

Sir

28

1 8

32

50

42

21-

1 8-

—

—

—

5708-118 5 35

66

Sym

Ell

27

1 7

40

054

54

21-

1 7-

1.5

5706-127 34

75

Sym

Ell

30

20

36

66

70

22-

18-

—

—

1 8

6912-83 60

83

Sym

E (1

32

1 8

42

60

66

24-

20-

—

—

20

5807-130.30

7.6

Sym

Midll

29

1 9

38

064

058

2 2-

2 0-

—

—

1 8

5709-110 30

79

Sym

Midfl

29

19

42

60

052

2 2-

2 0-

—

_

17

6706-12337

88

Sym

Midtl

34

23

44

68

060

28-

24-

—

—

24

5706-12337

76

Sym

L (1

3 1

2 1

46

66

64

2 5-

2 3-

—

—

18

6706-123 36

85

Sym

L II

34

23

44

70

66

2 8-

2 6-

—

—

23

6608-120 30

7 1 SL

Sym

Flexed

3 1

22

46

76

78

2 6-

2 4-

66

062

21

5708-115 35

80

Sym

Flexed

33

24

064

72

68

29-

27-

062

070

20

6706-123 37

90

Sym

Flexed

39

27

52

84

84

3 4-

3 0-

070

82

27

6410-83 43

94

Sym

Flexed

37

27

56

84

84

3 6-

3 8-

80

84

23

5701-120 35

9 1

Migr

Flexed

38

3 1

72

1

96

3 7-

4 r

092

68

27

5709-110 33

99

Migr

Flexed

40

32

80

90

086

4 1'

43-

0.90

76

26

6706-123 36

105

Migr

Flexed

4 1

35

80

1 1

94

3 8-

3 9'

98

88

30

5507-130,30

11 7

Migr

Flexed

42

37

096

10

088

44-

4 5-

12

0.90

35

Asuncion Bay.

358

Over

Juv

124

12,2

23

4,3

—

134-

130-

3.2

2.9

10.5

BC

38 2

Over

Juv

122

13,5

27

42

—

14,2-

13.7-

3.8

3.4

11.4

'Sym - symmetrical. Migr - migrating

^Str straight, E tl - early llexion, Midll - midflexion, L tl - late flexion, Juv - luvemle.

^Asterisk indicates inclusion ol dorsal tin pterygiophores in body depth measurement.

Table 19. — Menstics of larvae and juveniles oi Hippoglossina stomata.
(Specimens between dashed lines are undergoing notochord flexion.)

Size

Fin rays

Vertebrae

Pectoral

Source

Station

(mm)

Stage'

Dorsal

Anal

Caudal

Pelvic

righflell

Precaudal Caudal

Total

ol count

7201-117 35

3 7 NL

Prell

LP^

7412-103 29

4 1

Prell

LP2

7412-88531

4.8

Prell

LP^

5801-11735

5.2

Pretl

LP'

6310-93 28

6.2

Pretl

LP'

6605-123 37

6.4

Prell

Anterior
swelling

LP'

5910-117 30

6 2

Prell

Forming

Forming

LP'

6706-110 50

70

Prell

Forming

Forming

ca 6

LP'

5708-118 5 35

66

Ell.

Forming

Forming

ca 6

Bud

LP'

5706-127 34

75

Efl

Forming

Forming

ca 10

Bud

LP'

6912-83 60

83

Ell

Ant 4

Forming

ca 10

Bud

LP'

5807-130 30

7.6

lyiidll

ca 15

ca 15

12

Bud

LP'

5709-110 30

7.9

Midfl

ca 55

ca 45

12

Bud

LP'

6706-123 37

8.8

Midtl

ca, 62

ca 50

16

Bud

LP'

5706-123 36

7.6

Lfl

ca 63

ca 45

14

Bud

LP'

6706-123 36

8.5

Lll

ca, 68

ca 50

14

Bud

LP'

6608-120 30

7 1 SL

Postll

ca 66

ca 51

16

ca, 5/5

LP'

5708-115 35

8.0

Postll

63

50

ca 18

6/6

LP'

6706-123 37

9.0

Postll

68

53

18'i

5,' 5

LP'

6410-83 43

9.4

Postll

68

54

ca 18

6/6

LP'

5701-120 35

9.1

Postll

67

53

18''i

66

LP'

5709-110 33

9.9

Postll

65

50

18',i

6/6

LP'

6706-123 36

10.5

Postll

66

53

18'/i

6/6

LP'

5507-130 30

11.7

Postll

64

50

18'/!

6/6

LP'

Asuncion Bay.

35.8

Juv

67

52

18"j

6/6

10,'10

11 27

38

x-ray

BC

38 2

Juv

65

50

1 7','i

6/6

10/10

11 27

38

X-ray

'Prell - prellexion. E fl

- early flexion

Midll - midllexion, L 11

- lale llexion

: Postfl, -

postllexion

Juv - juvenile

^LP refers to functional larval pectoral fins which have no ossified rays.

140

SUMIDA ET AL EARLY DEVELOPMENT OF SEVEN FLATFISHES

character in H. stomata because other species of
Hippoglossina possess this bone.

The dorsal fin of//, stomata develops quite dif-
ferently than in Pleuronichthys. An anterior
group of about five dorsal rays is the first to form in
H. stomata; these become more elongated than the
other rays. The anlage of these is evident on a
6.4-mm NL preflexion specimen and four rays are
formed on a 9.3-mm NL early flexion larva. A
similar pattern of early forming dorsal fin rays is
found in the closely related genera Paralichthys
(Okiyama 1967; Smith and Fahay 1970; Ahlstrom
and Moser 1975) and Pseudorhombus (Devi 1969).
Although the anterior dorsal rays form early, the
pelvic fins do not develop elongated rays, such as
in the bothid genera Syacium (Aboussouan 1968)
and Cyclopsetta (Gutherz 1970). The dorsal fin
rays differentiate posteriad but most rays form
simultaneously and the full complement is de-
veloped on a late flexion specimen. The base of the
anal fin is evident during early caudal formation,
rays are forming on midflexion specimens, and the
total number is formed on a late flexion specimen.
Pelvic fin buds are evident on early flexion speci-
mens, but rays can be distinguished only on post-
flexion larvae.

Distribution. — This species ranges from Monterey
Bay, Calif., to the Gulf of California, including
Guadalupe Island (Miller and Lea 1972). Larvae
occurred over a wide band of inshore and offshore
stations (Figure 24). The southern limit of H.
stomata overlaps the northern range of H. tet-
rophthalmus which has different fin counts
(Ginsburg 1952). To date, larvae of H. tet-
rophthalmus are not known.

SUMMARY

We used a combination of larval morphology,
meristics, and pigmentation to distinguish seven
known eastern North Pacific species of flatfishes
with heavily pigmented larvae. Table 20 sum-
marizes many pertinent characters for identifying
eggs and larvae of these species. Information is
given for three characters of eggs; size, ornamen-
tation of the chorion, and presence or absence of an
oil globule.

In most instances, the size of a newly hatched
larva is directly related to the size of the egg from
which it hatched, and such is the case with
Pleuronichthys. Pleuronichthys decurrens. with
the largest egg, has the largest larva, with a suc-

40'

35'

30'

25'

20'

129°
"7

125°

"7 — r

CAPE

MENDOCINO

^MONTEREY
BAY

POINT
'CONCEPTION

O rJ SAN

DIEGO

\

O c* \,

;

A

J£]

\i.

O O

o

Y^ POJNT
\ EUGENIA
O Ox

o oof

'^

A

} GULF \

o

o y

.CALIFORNIA

•A

MAGDALENA.-^'^^

. (

BAT

\ ;

. ^

440

40°

35°

30°

25°

115°

)06°

FiGL'RE 24. — Distribution of eggs and larvae o^ Hippoglossina
stomata examined in this study. (Triangles represent eggs,
open circles larvae, and closed circles eggs and larvae.)

cessive decrease in larval size of the other species
corresponding to their smaller sized eggs. This
also applies to the yolk-sac larvae of Hypsopsetta
guttulata and Hippoglossina stomata. Pleuron-

141

FISHERY BULLETIN VOL 77. NO 1

ichthys decurrens. with the largest yolk-sac larva,
is correspondingly large at caudal fin formation
(notochord flexion) and at transformation,
whereas Hypsopsctta guttiilata. with the smallest
egg, is correspondingly smallest at all stages of
larval development with the exception of some
overlap with larvae of P. ritten.

A larval character that is particularly useful in
separating preflexion larvae of H. guttulata from
those of P. ritten is the presence of a pterotic spine
on each side of the head of//, guttulata. The only
species of Pleuronichthys with a pterotic spine is
P. decurrens.

For relating a lai'val series to its juveniles and
adults, and thus substantiating identification of
the series, meristic counts, particularly of the pre-
caudal and caudal groups of vertebrae, are indis-
pensible. One can seldom rely on one meristic
character alone, but must use a combination of all
available counts.

The distribution of pigment, which changes
with growth, provides good characters for dis-
criminating among larvae of the several species. It
is particularly useful with preflexion larvae, and
for this reason we emphasize pigment for this
stage in Table 20.

ACKNOWLEDGMENTS

We would like to thank the following individu-
als for loan of specimens: Gerald McGowen (Occi-
dental College), Joseph Copp and Richard
Rosenblatt (Scripps Institution of Oceanography),
Maxwell Eldridge (National Marine Fisheries
Service, Tiburon), Wayne White (California State
University, Fullerton), Robert Behrstock (Hum-
boldt State University), and Sally Richardson
(Oregon State University). We are grateful to Den-
nis Gruber (Scripps Institution of Oceanography)
and John Butler (National Marine Fisheries Ser-
vice, La Jollai for providing reared specimens. .Ap-
preciation is also extended to Susan D'Vincent,
Elaine Sandknop, and Betsy Stevens (National
Marine Fisheries Service. La Jolla) for their assis-
tance in gathering material from our collections.
Henry Orr ( National Marine Fisheries Service, La
Jolla) deserves thanks for some of the illustra-
tions. Our special thanks go to George Boehlert
and Ellen Flentye (Scripps Institution of Oceanog-
raphy) for providing the scanning electronmicro-
graphs, and to John Fitch (California Department
of Fish and Game), Edward Houde (University of
Miami), David Kramer (National Marine

Fisheries Service, La Jolla), and Sally Richardson
for their critical review of the manuscript.

LITERATURE CITED

ABOUSSOUAN, A.

1968. Oeufs et larves de Teleosteens de I'Ouest africain
VII. Larves de Syacium guineensis (Blkr.l
IBothidae], Bull. Inst Fondam. Afr. Noire, Ser. A Sci
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AGAS.SIZ. A., AND C. O. WHITMAN.

1885. Studies from the Newport Marine Laboratory. XVI.
The development of osseous fi.shes, I , The pelagic stages of
young fishes. Mem. Mus. Comp. Zool Harv. Coll. 14. 56

P

AHL.STROM. E. H.. AND H. G. MOSEK.

1975. Distributional at'.as of fish larvae in the Cahfomia
Current region: Flatfishes, 1955 through 1960. Calif.
Coop. Oceanic Fish, Invest. Atlas 23. text vii-xix, 207
distribution charts.

AHL.STROM, E. H., J. L, BUTLER, AND B. Y. SUMIDA.

1976. Pelagic stromateoid fishes (Pisces, Perciformes) of
the eastern Pacific: Kinds, distributions, and early life
histories and observations on five of these from the north-
west Atlantic. Bull. Mar. Sci. 26:285-401.

AMAOKA, K.

1970. Studies on the larvae and juveniles of the sinistral
flounders - I. Taeruopsettn ocellata (Giinther). Jpn. J-
Ichthyol. 17:95-104,

1971. Studies on the larvae and juveniles of the sinistral
flounders — II. Chascanopsetta lugiibris. Jpn J
Ichthyol. 18:25-32.

1972. Studies on the larvae and juveniles of the sinistral
flounders— III. Laeops kilaharae. Jpn. J. Ichthyol.
19:154-165,

1973. Studies on the larvae and juveniles of the sinistral
flounders — IV. Arnoglossusjaponiciis. Jpn, J. Ichthyol.
20:145-156.

B AILEY, R, M. J. E. FITCH, E. S. HERALD, E. A. LACHNER, C. C.
LINDSEY, C, R, ROBINS, AND W, B. SCOTT,

1970, A list of common and scientific names of fishes from
the United States and Canada. 3d ed. Am. Fish. Soc,
Spec. Publ. 6, 150 p.

Bell, R. R.

1971. California marine fish landings for 1970 Calif
Dep Fish Game, Fish Bull, 154:33-34,

Bruun, a, F,

1937. Chat^canopsetta in the Atlantic; a bathypelagic oc-
currence of a flat-fish, with remarks on distribution and
development of certain other forms. Vidensk. Medd
Dan. Naturhist. Foren. Kbh. 101:125-135.
BUDD, P. L.

1940. Development of the eggs and early larvae of six
California fishes. Calif. Div. Fish Game, Fish Bull. 56.
50 p.

Clothier, C. R.

1950. A key to some southern California fi.shes based on
vertebral characters. Calif Div. Fish Game, Fish Bull,
79, 83 p,
DEVI, C, B, L

1969. Occurrence of larvae of Pseudorhomhus elevatus
Ogilby (Heterosomata— Pisces! along the south-west
coa.st of India. Proc. Indian Acad. Sci. 70(Sect. Bi: 178-1 86

142

SUMIDA ET AL EARLY DEVELOPMENT OF SEVEN FLATFISHES

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FISHERY BULLETIN VOL. 77, NO. 1

EHRENBAUM, E.

1905. Nordisches Plankton. Zoologischer Teil. Erster
Band: Eier und larven von Fischen. 1905 p. 1-216 Lab-
ridae through Pleuronectidae, 1909 p. 217-414 Gadidaeto
Amphioxidae. Reprinted 1964 A. Asher and Co.. Amster-
dam.
ELDRIDGE. M. B.

1975. Early larvae of the diamond turbot.Hypsopsetla gut-
tulata. Calif. Fish Game 61:26-34.

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Fitch, J. E.

1963. A review of the fishes of the genus Pleuronichthys.
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1971. California's livmg marme resources and their utili-
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1952. Flounders of the genus Paralichthys and related

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1971. Larvae of the fourspot flounder, Hippoglossina ob-
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SUMIDA ET AL EARLY DEVELOPMENT OF SEVEN FLATFISHES

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145

ASSOCIATIONS OF TUNA WITH FLOTSAM IN
THE EASTERN TROPICAL PACIFIC

Paul R. Greenblatt'

ABSTRACT

The fishing record for flotsam-associated tuna in the eastern tropical Pacific was examined. The rivers
of Central America are probably the major source of flotsam. Correlation analysis ofthe number of sets
occurring in an area indicates that unassociated tuna and flotsam-associated tuna are related. The
number of sets made on floating objects has increased dramatically since 1971. The percentage of
flotsam-associated sets has increased, indicating that flotsam-associated sets are more important to the
tuna fishery than in 1963. The catch per set of tuna associated with flotsam has also increased markedly
since 1967. Analysis of length-frequency data indicate that, on a single set basis, tuna fork length is
more variable in sets associated with flotsam than with unassociated schoolfish sets. Results of the
length-frequency analysis support the idea that flotsam aggregates tuna.

The catch of the eastern tropical Pacific tuna
fishery consists of mostly yellowfin tuna, Thunnus
albacares, and skipjack tuna, Katsuwonus
pelamis. The catch is frequently categorized by the
conditions under which the purse seine set is
made. Scott 1 1969) made a major distinction be-
tween associated schools and unassociated
schools. Associated schools are caught either in
"porpoise sets" (sets associated with porpoise) or
"floating object sets" (sets associated with logs or
other flotsam). Unassociated schools are caught in
"night sets" (sets made at night with the aid of
bioluminescence) and "schoolfish sets" (schools
seen and set upon during the day). Night sets
compose a very small proportion of total sets and
will not be discussed in this paper. Porpoise sets
catch mostly yellowfin tuna. Floating object sets
and schoolfish sets catch yellowfin and skipjack
tuna, either as pure or mixed species.

Little is known about the attraction of tuna to
flotsam. Gooding and Magnuson (1967) and
Hunter and Mitchell (1968) observed fish gather-
ing around flotsam. These authors attracted some
tuna to their flotsam, but never large schools.
Tuna were a minor portion of the observed fish
assemblages. Hunter and Mitchell ( 1968) postula-
ted a connection between schooling behavior and
the attraction of fish to flotsam. They concluded
that flotsam had the function of providing (p. 27)
"... a visual stimulus in an optical void." Gooding

'Southwest Fisheries Center La Jolla Laboratory, National
Marine Fisheries Service. NOAA, La Jolla. Calif; present ad-
dress: Code A-008, Scripps Institution of Oceanographv. Univer-
sity of California, La Jolla, CA 92093.

Manuscript accepted August 1978

FISHERY BULLETIN VOL. 77, NO, 1. 1979.

and Magnuson ( 1 967) concluded that fish gathered
around floating objects at sea primarily because
the objects provided shelter from predation. It may
be possible that the same factors attracting small-
er fish also attract large tuna schools.

This paper examines historical tuna fishery
data on the catches of yellowfin and skipjack tuna
associated with floating objects in the eastern
tropical Pacific from 1963 to 1975. The objectives
ofthe paper are to 1 ) establish the main sources of
flotsam, 2) determine if there is a connection be-
tween various set types, 3) see if flotsam-
associated sets have become more important to the
tuna fishery, 4) determine if the catch rate on
flotsam-associated sets has changed, and 5) assess
whether flotsam does aggregate tuna schools.

METHODS

Since the catch of tuna associated with flotsam
depends on the presence of tuna, flotsam, fisher-
men, strength of attraction, and suitable fishing
conditions, I examined each factor in light ofthe
published literature and available fishery data
from the eastern tropical Pacific tuna fishery.

The Inter- American Tropical Tuna Commission
( lATTC) collects information from tuna fishermen
operating in the eastern tropical Pacific. Informa-
tion collected in logbooks includes date and loca-
tion of sets, catch of various species, type of set,
and environmental conditions. Although these
logbooks remain confidential, it is possible to ob-
tain summaries of the information for certain
time-area strata. During the beginning portion of

147

FISHERY BULLETIN VOL 77, NO. 1

the year, yellowfin tuna fishing is unregulated.
After a quota is reached (Table 1), all yellowfin
tuna fishing, except for special allowances must be
outside the Commission's Yellowfin Regulatory
Area (CYRA) (Figure 1). Due to special rules (see

Table l. — Yellowfin quota (thousands of short and metric tonsi.
closure data, and annual total catch (thousands of short and
metric tons) for the Commission's Yellowfin Regulatory Area,
taken from Calkins ( 1976).' Metric tons are given in parenth-
eses.

Quola

Closure

Annual

Year

Quota

+ inaement^

dale

total catch

1966

79 3 ( 71 9)

Sept 15

91 1 ( 82 6)

1967

84.5 ( 76 6)

June 24

89 6 ( 81 3)

1968

106 0( 96 1)

June 18

1146 (1039)

1969

120 (108 8)

Apr 16

1265 (1147)

1970

1200(108 8)

Mar 23

1426 (129 3)

1971

140 0(127 0)

Apr 9

1139 1103 3)

1972

120 0(108 8)

140 0(127 0)

Mar 5

152 5(138 3)

1973

130 (117 9)

1600(145 1)

Mar 8

177 8 (161 3)

1974

175 (158 7)

195 0(176 9)

Mar 18

191 3 (173 5)

1975

175 0(158 7)

1950(176 9)

Mar 13

1772 (160 7)

1976

175 0(158 7)

1950(176 9)

Mar 27

205 5(186 4)

The 1976 fishrng year (through August
. 33rd meeting of the Inter-American Tropical

'Calkins. T P 1976
30) Background Paper No
Tuna Commission

^The Director ot lATTC may increment the established quota, allowing more
yellowlm tuna to be caught

Figure l. — Eastern tropical Pacific fishing area divided into
three nearshore areas lAreas l-3i and one offshore area (Area 4).
The heavy line to the west delimits the boundary' for the Com-
mission Yellowfin Area (CYRA). The average number of
flotsam- associated sets from 1972 to 1975 by 5" squares is shown.
Data represent the unregulated fishing period isee text).

Inter-American Tropical Tuna Commission
1967-1975), any detailed reporting of regulated
data would compromise the confidentiality of the
data; hence, only unregulated catch and number of
sets within the CYRA summarized by month and
5' square for 1963-75 were made available to me.

The total number of unregulated sets during the
13 yr was approximately 161,000 of which 8,190
were associated with flotsam. In addition, the
lATTC provided the total number of flotsam-
associated sets occurring each year ( Figure 2 ). One
sees that the major trends in the number of sets
are contained in the block of unregulated data.

NOAA's Southwest Fisheries Center (SWFC)
periodically sends technicians aboard tuna sein-
ers. These technicians record details about set
type, catch, environmental conditions, as well as
the fork length (centimeters) of tuna sampled from
individual sets. Fork lengths of yellowfin and skip-
jack tuna wereonly available for a limited number
of sets made in 1973-75. The location of fork length
measurements are given in Table 2. Single set
catch data were collected by SWFC technicians in
1974-76 (unpubl. data^).

^Unpubl. data on file at the Southwest Fisheries Center. Na-
tional Marine Fisheries Service, NOAA, P.O. Box 271, La Jolla.
CA 92038.

2,000 -

1963 1965 1967 1969 1971 1973 1975
YEAR

Figure 2. — Total number of flotsam-associated sets made in the
eastern Pacific and number of unregulated flotsam-associated
sets made in the CYRA, 1963-75.

148

GREENBLATT ASSOCIATIONS OF TUNA WITH FLOTSAM

Table 2. — Spatial distribution of fork length measurement
( centimeters) of yellowfin and skipjack tuna m the Commission's
Yellowfin Regulator>- Area. 1973-75. C YRA subareas are shown
in Figure 1. (Source of data, SWFC.)

CYRA subarea

Number of sets where tork lengtti was measured

1

56

2

12

3

14

4

29

Monthly rainfall in Central America was calcu-
lated by averaging the stations reporting to the
Environmental Data Service (U.S. Department of
Commerce 1963-1975).

In order to achieve the objectives of this paper,
the data obtained from lATTC and SWFC were
examined and analyzed in several ways. The main
sources of flotsam were inferred by examining the
average distribution of flotsam-associated sets
and consideration of the average surface circula-
tion.

Two methods may be used to determine if differ-
ent set types are related: correlation of set types
occurring in an area and comparison of fork length
distributions (length-frequency gi-aphs) stratified
by species and set type. Spearman's rank correla-
tion coefficient (Siegel 1956) was calculated to ex-
pose possible correlations of numbers of sets. Fork
length distributions were weighted by the catch in
each set. A high positive correlation between set
types occuring in an area would indicate a rela-
tionship between set types. Similar looking
length-frequency distributions would serve as
further evidence that set types are related.

An increase in the percentage of flotsam-
associated sets would be evidence that flotsam-
associated sets have become more important to the
fishery. The CYRA was subdivided into three
nearshore areas and one offshore area (Figure 1).
Stratifying the number of flotsam-associated sets
by area allows the determination of area effects.
Hence, the importance of flotsam to the fishing
industry may be determined by the percentage of
flotsam-associated sets occurring each year and
stratifying the number of flotsam-associated sets
by area.

Average rainfall was tabulated to determine if
any connection existed between river runoff and
the number of flotsam-associated sets.

Catch rate is an indicator of the importance of
flotsam-associated sets to the tuna fishery. Calcu-
lation of the average yearly catch per set (includ-
ing zero catch sets) for different set types should

demonstrate any trends as well as the relative
value of making one set type over another.

Calkins (1965) examined tuna length distribu-
tions from single sets in the eastern tropical
Pacific, finding that single unassociated schoolfish
sets caught tuna of a relatively uniform size (i.e.,
small variance in length). If the fish caught in
flotsam-associated sets represent aggregations of
solitary tuna, portions of schools, or several
schools, then one would expect the variance of
tuna length to be greater than for unassociated
schools. In order to examine if floating objects act
as aggregators, length-frequency data were strat-
ified by species and set type. Mean length and
standard deviation were calculated on a single set
basis for each category and compared using
Kruskal-Wallis one-way analysis of variance by
ranks (Siegel 1956).

If flotsam does aggregate tuna, one would expect
more of the larger flotsam-associated sets than
unassociated sets. Differences in catch distribu-
tion were observed by plotting histograms of tons
of tuna caught per set stratified by year and set
type and by calculating catch per successful set for
each year and set type. The single set catch data,
collected by SWFC technicians, existed for the
1974-76 period.

RESULTS

The availability of logs or other flotsam in an
area are determined by the source of the flotsam
and the currents in the area. Large rivers flow into
the Pacific from southern Mexico (lat. 20°N) and
continue down the coast of South America (to lat.
20°S). These rivers are capable of releasing many
logs into the Pacific during the rainy season.
SWFC and lATTC observers reported large densi-
ties of logs near the Gulf of Tehuantepec (lat.
16°N, long. 100°W), the Gulf of Nicoya (lat. lO'^N,
long. 85°W), and the Gulf of Fonseca (lat. 13°N,
long. 87°W).

The average yearly number of flotsam-
associated sets in 1972-75 were plotted by 5°
squares (Figure 1). In general, most flotsam-
associated sets occurred in Areas 1 and 2. Most of
the offshore flotsam-associated sets (i.e., Area 4)
occurred quite close to Areas 1 and 2. Area 3 did
not have large numbers of flotsam-associated sets.
If the main source of logs and other flotsam is the
rivers of Central America, then it is important to
examine the major current patterns in the eastern
tropical Pacific to determine if the currents can

149

FISHERY BULLETIN: VOL 77, NO 1

explain the observed distribution of flotsam-
associated sets.

The average currents in the eastern tropical
Pacific, as derived from ship's drift data, were de-
termined by Wyrtki (1965). From January until
May, the California Current is strong. Circulation
near Area 3 is to the south. Circulation near Areas
1 and 2 is gyral. From May to July, both the
Equatorial Countercurrent and the California
Current are relatively stong. During this period,
most countercurrent water turns north and flows
along the coast of Central America. Area 3 has a
northern and southern flow, the northern flow
along the coast. Area 1 maintains its gyral flow.
From August through December, the Equatorial
Countercurrent is well developed. Circulation in
Area 3 is to the south. Area 2 maintains its north-
western flow along the coast and Area 1 flow main-
tains a gyral pattern. If logs disperse mainly from
the Gulf of Nicoya, the Gulf of Tehuantepec. and
the Gulf of Fonseca, then the gyral circulation in
Area 1 would tend to maintain logs and other
flotsam in the area for a considerable time. The
northwest coastal current in Area 2 could trans-
port flotsam through Area 2 and during part of the
year into Area 3. Since the North Equatorial and
South Equatorial Currents are rather strong, one
would not expect floating objects to persist in Area
4 except near the boundaries with Areas 1 and 2.
Hence the location of large rivers and the system
of currents is reasonably consistent with the geo-
graphical distribution of flotsam-associated sets.

In order to compare different set types, Spear-
man's rank correlation coefficient was calculated.
For each 5° square in the C YRA, the total numbers
of flotsam-associated sets, porpoise-associated
sets, and unassociated schoolfish sets were tabu-
lated for each year. These totals were ranked and
the ranks were correlated. Only 5° squares where
at least 10 sets occurred were used in calculating
correlations. When a minimum of 40 sets was used
as the criterion for including a 5° square, the corre-
lations were qualitatively the same as with the 10
sets criterion. The results (Table 3) show that a
significant positive correlation exists between
number of sets on unassociated schoolfish and
flotsam-associated tuna. Porpoise sets were uncor-
rected with other set types.

The above results indicate that fish caught as-
sociated with flotsam tended to be caught in the
same area at the same time as unassociated school
fish. Examination of available length-frequency
data on a species basis, weighted by the catch in

T.^BLE 3. — Spearmans rank correlation between three types of
sets by year. Number of sets/5° square. (Source of data: I ATTC . )

Year

N

Unassociated
schoollisri

and porpoise-
associated

Unassociated
schoolfish

and flotsam^
associated

Porpoise
and flotsam-
associated

1963

29

-0,0008

5421"

2538

1964

27

0375

1581

08138--

1965

25

■0 1597

3498'

1318

1966

28

■01110

03513-

02914

1967

24

■92379

4621-

■0,2255

1968

24

■0 1951

1886

03463-

1969

25

-0 1523

05957--

02294

1970

27

■0 0088

03529-

■00173

1971

26

0803

5819"

0,2398

1972

32

■0 0200

05277--

■00558

1973

34

0523

3086-

0,1796

1974

27

0-0168

04847"

0,0001

1975

33

02444

0,5139"

00526

•Si.
"Si

gnificant at Ps
gnrticant at Ps

05

;0 01

each set (Figure 3), indicated that unassociated
schoolfish and flotsam-associated yellowfin and
skipjack tuna had very similar length-frequency
distributions. The length-frequency information
and the correlation analysis support the idea that
unassociated tuna and flotsam-associated tuna
are related. Flotsam, acting as an attractant, may
aggi-egate tuna that would otherwise be caught in
unassociated sets.

The number of flotsam-associated sets has in-
creased dramatically since 1971 (Figure 2). The
trend in percentage of flotsam-associated sets (Fig-
ure 4) indicates that flotsam-associated sets have
increased in importance to the fishery. Stratifying
the number of unregulated flotsam-associated sets
by area (Figure 5i shows that the trend of more
flotsam-associated sets is not an area effect. All
areas, except Area 3, have shown a marked in-
crease in number of flotsam-associated sets. Area
3 does not show an increase because logs are only
deposited in this region during a limited portion of
the year. In January-May, the near surface cur-
rent in Area 3 is to the south (Wyrtki 1965), cut-
ting off the source of logs that wash down the
rivers of Central America. Also, good fishing often
occurs in Area 3 during the later months of the
year, a period not included in my unregulated
data. It appears that the increase in flotsam-
associated sets in recent years was not caused by
discovery of new areas with abundant flotsam but
rather by an increase in fishing effort on flotsam in
all areas but Area 3.

Average rainfall in Central America was tabu-
lated (Table 4) to see if there was a correlation
between river runoff and the number of flotsam-
associated sets. Comparison of number of
flotsam-associated sets and rainfall revealed only

150

GKEENBLATT ASSOCIATIONS OF TUNA WITH FLOTSAM

SKIPJACK SCHOOLFISH

SKIPJACK ASSOCIATED
WITH FLOTSAM

30 *0 50 60 'G 80 90 100 ilO l£0 tJO 30 40 50 60 '0 80 9C' lOO mO

20r

Figure 3— Length-frequency distribu-
tions of yellowfin and skipjack tuna
caught in unassociated schoolfish and
flotsam-associated sets Data collected
1973-75 in the CYRA (see Table 2).

YELLOWFIN SCHOOLFISH

I I I I I I 'I

FORK LENGTH (cm)

YELLOWFIN ASSOCIATED
WITH FLOTSAM

20 1-

TABLE 4. — Average yearly rainfall (centimeters) in Central
America in 1963-75, (Source; U.S. Department of Commerce.)

1963 64 65 66 67 68 69 70 71 72 73 74 75
YEAR

Figure 4. — Percentage of total unregulated sets that were as-
sociated with flotsam in the CYRA. 1963-75.

small similarities, indicating that the supply of
suitable flotsam was not greatly influenced by
rainfall.

Comparing the average catch per set of different
set types indicates the relative importance of each
set type to the fishery as well as showing trends in
the catch rate (Figure 6). All set types had similar
catch rates in 1963-66. Porpoise sets and flotsam-
associated sets gave much higher catch per set
than unassociated sets in 1971-75. One sees that
flotsam-associated sets have been the most valu-
able set type for the tuna fisherman since 1971.

Average yearly

Average yearly

Year

rainfall

Year

rainfall

1963

139

1970

163 8

1964

136,4

1971

145-5

1965

136 9

1972

145-6

1966

158,5

1973

161 4

1967

151,7

1974

172 3

1968

177J

1975

151

1969

177 2

Fork length data was stratified by set type and
species. The mean length, standard deviation, and
sample size were calculated on a single set basis
(Table 5). The average standard deviation of fork
length of yellowfin and skipjack tuna associated
with flotsam was larger than the standard devia-
tion found in unassociated sets, though the mean
fork length of flotsam-associated sets was smaller.
The probability of getting the results shown (Ta-
ble 5) by chance was calculated using Kruskal-
Wallis one-way analysis of variance (Siegel
1956: 184) (Table 5 1. The greater variability of fork
length of flotsam-associated tuna supports the
hypothesis that flotsam aggregates tuna.

The yellowfin and skipjack tuna catch distribu-
tion on flotsam-associated sets was compared with
unassociated schoolfish sets. The average catch
per successful set was calculated and the data
were plotted as histograms of tonnages using an
arbitrary interval of 5 tons (Figure 7). The main

151

FISHERY BULLETIN VOL 77. NO, 1

Figure 5— Number of unregulated
flotsam-associated sets per month by
area. 1963-75.

of;^,Ayv.,-,/, ^l\

A

A

-<Y - ^^—^i'^**, '*,

aw

ENTIRE CYRA

vA4MvV^

25i-

20

FLOTSAM-ASSOCIATED

SETS 1

UNASSOCIATED
SETS

PORPOISE-
ASSOCIATED SETS

J L

-J-J L^

' 1963 1965 1967 1969 1971 1973 1975

YEAR

Figure 6.— Average yearly catch per set of yellowfin and skip-
jack tuna in flotsam-associated, unassociated schoolfish. and
porpoise-associated sets in the CYRA.

differences between the histograms for unas-
sociated schoolfish sets and flotsam-associated
sets are a lower proportion of unsuccessful sets and
a higher percentage of flotsam-associated sets
with catches between 25 and about 60 tons. The
higher proportion of large flotsam-associated sets
is consistent with the hypothesis that flotsam
aggregates tuna.

DISCUSSION

Changes in catch rate (catch per set. Figure 6) of
flotsam-associated yellowfin or skipjack tuna may
be related to overall abundance of flotsam-
associated schools, technological advances such as
bigger nets, increased skill and knowledge of the
fishermen, changes of the attractability of flotsam,
and changes in the residence time of tuna with
flotsam. In order to explain the observed increase

152

GREENBLATT ASSOCIATIONS OF TL'NA WITH FLOTSAM

Table 5. — Variability of fork length (centimeters) in single set
data by tuna species and set type, as indicated by average stan-
dard devation (Si and mean ix) and results of Kruskal-Wallis
one-way analysis of variance of standard deviations- (Source of
data: SWFC.i

Hem

Yellowfin tuna

Skipjack tuna

Flotsam-associated sets

N

35

45

S

4.96

4.62

X

55,55

52.49

Unassociated schoolfish

N

49

43

S

3,76

3.40

X

60 94

54.08

Kruskal-Wallis

H

3.69

33.31

d(

1

1

Probability level

OOSsPsO 1

PS0 001

in catch rate, it was necessary to examine data
that could indicate which factors have most
influenced catch rate. Changes in attractability.
changes in residence time, technological ad-
vances, and increased knowledge of the fisherman
could not be rejected or confirmed with existing
data. It was possible, with some assumptions, to
determine if overall abundance changes or in-
creased skill of the fisherman could explain the
increased catch rate.

If the overall abundance of tuna had increased
from 1963 to 1975, then one would expect the catch
rate to have increased correspondingly. If one ac-
cepts the supposition that flotsam-associated fish
were from the same population as unassociated
schoolfish. then one would expect the catch rate on
unassociated schoolfish to have likewise in-
creased. The catch per set on unassociated
schoolfish (Figure 6) showed no increase. How-

ever, the year-to-year variations in catch per set of
flotsam-associated tuna and unassociated tuna
(Figure 6) were remarkably similar. The above
evidence indicates that changes in overall abun-
dance does not explain the long-term increase of
catch per set in flotsam-associated sets. The simi-
larity of the year-to-year variations supports the
hypothesized relationship between unassociated
schoolfish and flotsam-associated tuna. The year-
to-year variation may represent changes of abun-
dance.

The second explanation for the changes in the
catch rate of flotsam-associated tuna schools,
changes in the skill of the fisherman, can be
evaluated by the percentage of successful sets. An
increase in the percentage of successful sets on
schools associated with flotsam would explain the
apparent increase in catch per set. Such an expla-
nation is untenable because the percentage of suc-
cessful sets would have had to more than double.
Greenblatt (1977) calculated the percentage of
successful sets associated with flotsam for 1974-
76, finding the average percentage of successful
sets to be 75'7f . To account for the change in catch/
set, the percentage of successful sets in 1963 would
have had to have been about 35%, an unreason-
ably low figure. Pella and Psaropulos ( 1975, fig. 2)
showed that the percentage of successful sets of
unassociated schoolfish sets and flotsam-
associated sets ( considered as one category ) did not
increase enough in 1961-71 to account for the ob-
served changes in catch per set. Bayliff and
Orange (1967) reported percentages of successful
sets stratified by set type for a limited area of the

FIGURE 7,— Distribution of catch by 5
short ton intervals for flotsam-
associated sets and unassociated
schoolfish from 1974 through 1976,
Solid boxes indicate percentage of zero
catch sets. The average catch per suc-
cessful set (CPSSi in short and metric
tons is given for each category. Metric
tons are in parentheses.

1974
UNflSSOCiaTED SCHOOLFISH

CPSS = 2071
llB7e)

IrlThrrPn

Iw

OU-

25 i.0 75 >iOO

FLOTSftM ASSOCIATED
U-- 265
CPSS = 24 07
{21 63)

1975
UNflSSOCIATEO SCHOOLFISH

CPSS = 16 07
(14 5B)

I hi n n r

1975

FLOTSAM ASSOCIATED

N^20e

CPSS = 27 30

124 76)

njfrh-rw.

1976

UNASSOCIATED SCHOOLFISH

N = 98l

CPSS = 21 21

(19 24)

25 50 75 >I00

\m.

_a — q

1

SHORT TONS

1976

FLOTSAM ASSOCtATED

N= 550

CPSS = 26 04

(23 621

1 1 1 nhp-ii-n r

25 50 7l>

SHORT TONS

153

FISHERY BULLETIN VOL 77. NO. 1

CYRA. Although they had small numbers of sets,
the percentage of successful flotsam-associated
sets from 1962 to 1966 was 67.6'*. Changes in
percentage of successful sets can not adequately
explain the increased catch per set.

No satisfactory explanation for the increase in
catch per flotsam-associated set has been found.
Overall increases in abundance or increased skill
of the fishermen can not explain the increase. The
above factors may account for some of the increase.
Technological advances may account for the in-
creased catch rate. It is also reasonable to believe
that fishermen have learned to catch flotsam-
associated tuna more efficiently and the residence
time of tuna with flotsam has increased since
1967.

Changes in catch per set on flotsam-associated
sets may have been due to technological advances
such as bigger nets. If technological advances can
explain the increased catch per set on flotsam,
then either the catch per set on unassociated
schoolfish should have also increased or sets as-
sociated with flotsam prior to the technological
advances must have caught a low proportion of
potential catch. Nets have increased in size,
perhaps increasing the probability of catching yel-
lowfin and skipjack tuna which may aggregate
around flotsam. It is possible that bigger nets
could account for increased catch/set of flotsam-
associated sets without likewise affecting catch/
set on unassociated schoolfish sets.

Fishermen often will drift with logs for consid-
erable time, waiting for tuna aggregations to
reach an optimal size before setting the net. The
spread of such behavior throughout the fleet could
cause the overall catch per set of flotsam-
associated tuna to increase. Adequate data for
testing this "increased knowledge" hypothesis
was unavailable.

The marked changes occurring in flotsam-
associated tuna catch in 1963-75 coincided with a
large increase of effort and technology in the
porpoise-associated fishery (Green et al. 1971). It
is hypothesized that the increased effort and
technology in the porpoise-associated fishery may
have been related to changes in the catch rate of
tuna schools associated with flotsam.

When purse seiners set on porpoise, there is
often an incidental kill of the marine mammals.
Due to recent technological advances, the porpoise
kill has been reduced, but in earlier years of the
porpoise-associated fishery (the mid-1960's) por-
poise mortality was higher (Southwest Fisheries

Center^'). This incidental kill may have reduced
the porpoise population. The porpoise-associated
fishery first developed near shore and thus the
nearshore porpoise stocks have been affected for a
longer time than offshore stocks. One may reason-
ably speculate that, on a species basis, nearshore
porpoise stocks have been affected more by inci-
dental kills than offshore porpoise stocks.

The bond between tuna and porpoise is not un-
derstood. It is possible that the mechanisms in-
volved in the association of tuna with porpoise is
similar to those responsible for their association
with flotsam. Tuna associated with flotsam are, on
the average, smaller than tuna associated with
porpoise (Calkins 1965, tables 2 and 9; Sharp'').
Knudsen (1977) gave some evidence that tuna
caught in areas where porpoise fishing predomi-
nates were generally older and larger than in tra-
ditional schoolfish areas. Size overlap, however,
did occur (Calkins 1965). Assuming that the
number of porpoise schools have declined, the
probability of tuna encountering porpoise schools
has decreased. The probability of tuna aggregated
near flotsam encountering porpoise schools has
also decreased. Thus, as a result of decreased en-
counter rates with porpoise (slower transition
from flotsam to porpoise), the size of the aggrega-
tions of tuna near flotsam have increased.

In conclusion, the most likely sources of flotsam
are the large rivers of Central America. Indirect
evidence indicates that tuna caught in unas-
sociated schoolfish sets are from the same popula-
tion as tuna caught associated with flotsam. It
appears that the increase of flotsam-associated
sets from 1963 to 1975 was due to an increased
interest by fishermen and hence an increased
fishing effort on floating objects. The observed in-
crease in catch per set may have been a biological
change rather than a change in fishing technology
or skill.

ACKNOWLEDGMENTS

I would like to express my thanks to John
Hunter who provided guidance in several phases
of this study. His comments were extremely help-

"Southwest Fisheries Center. 1976. Report of the Work-
shop on Stock Assessment of Porpoises Involved in the Eastern
Tropical Pacific Yellowfin Tuna Fishery. SWFC Adm Rep,
LJ-76-29, 54 p. Southwest Fisheries Center. La Jolla, CA
92038.

"G. Sharp, Inter-American Tropical Tuna Commission.
Southwest Fisheries Center. La Jolla, CA 92038, pers. commun
April 1977.

154

GREENBLATT ASSOCIATIONS OF TLINA WITH FLOTSAM

ful. Richard McNeely first suggested the possible
interaction of porpoise and flotsam-associated
tuna. The Inter-American Tropical Tuna Com-
mission provided much of the data. William Flerx
and Richard Charter provided insight into the op-
eration of the fishery. Gary Sharp provided useful
information about yellowfin tuna. Rainfall data
were obtained from Eric Forsbergh. William
Lenarz, Douglas Chapman, and Robin Allen re-
viewed the paper and offered constructive com-
ments.

LITERATURE CITED

Bayliff, W. H., and C. J. Orange.

1967. Observations on the purse seine fishery for tropical
tunas in the eastern Pacific Ocean. Inter-Am. Trop.
Tuna Comm., Intern. Rep. 4, 79 p.

Calkins, T. P.

1965. Variation in size of yellowfin tuna iThunnus alba-
cares) within individual purse-seine sets. [In Engl, and
Span.) Inter-Am, Trop, Tuna Comm., Bull. 10:461-524.
GOODING. R. M., AND J. J. MAGNUSON.

1967. Ecological significance of a drifting object to pelagic
fishes. Pac. Sci. 21:486-497.

Green. R. E., W. F, Perrin, and B, P, Petrich,

1971. The American tuna purse seine fishery. In H.
Kristjonsson (editor), Modern fishing gear of the world.
Vol. 3. p, 182-194, Fishing News (Books) Ltd.. Lond,
GREENBLATT, P, R,

1977. Factors affecting tuna purse seine fishing ef-

fort, ICCATRep.Vol. VI(SCRS-1976). No, 1 Tropical
spp,. p, 18-31.

Hunter, J. R., and C. T. Mitchell,

1968. Association of fishes with flotsam in the offshore
waters of Central America. U.S. Fish Wildl, Serv, Fish.
Bull. 66:13-29.

Inter-American Tropical Tuna Commission.

1967-1976. Annual Report, 1966-1975. Inter-Am. Trop.
Tuna Comm., La Jolla, Calif

KNunsEN. P. F.

1977. Spawning of yellowfin tuna and the discrimination
of subpopulations, [In Engl, and Span.[ Inter-Am, Trop,
Tuna Comm,, Bull, 17:117-169.

PELLA, J. J., AND C. T. PSAROPULOS.

1975. Measures of tuna abundance from purse-seine oper-
ations m the eastern Pacific Ocean, adjusted for fieet-wide
evolution of increased fishing power, 1960-1971, [In Engl,
and Span.] Inter-Am. Trop. Tuna Comm.. Bull, 16:281-
400,

SCOTT, J, M,

1969, Tuna schooling terminology Calif Fish Game
55:136-140,

SlEGEL, S.

1956. Nonparametric statistics for the behavioral
sciences. McGraw-Hill Book Co,. N,Y , 312 p.
U.S. DEPARTME.NT OF COMMERCE.

1963-1975. Monthly climatic data for the world, NOAA,
Environ, Data Serv,, vol, 16-28, var, pagination,
WYRTKI, K,

1965, Surface currents of the Eastern Tropical Pacific
Ocean, [In Engl, and Span] Inter-Am Trop, Tuna Comm.,
Bull. 9:269-304.

155

DESCRIPTION OF LARVAE OF THE NORTHERN SHRIMP,
PANDALUS BOREALIS, REARED IN SITU IN KACHEMAK BAY. ALASKA

Evan Haynes'

ABSTRACT

Northern shrimp. Panda! us borealis. were reared in situ in Kachemak Bay. Alaska, from Stage I (first
zoeali through Stage VIII (second juvenile). Each of the six larval stages and first juvenile stage is
described and illustrated, and a bnef description is given for the second juvenile stage. Apparently
larvae of P borealis in Alaska waters have at least one less stage than larvae of P. borealis in either
British Columbia. Greenland, or Japan waters. Of the known larvae of the North Pacific Ocean, larvae
of P- borealis are most similar morphologically to larvae of P goniurus but are separable from them by
being slightly larger in size and, in zoeal Stages I-III, by bearing more setae on certain appendages,
particularly the antennal scale and certain mouth parts. From Stage IV to megalopa, the rostrum of P.
borealis has more dorsal teeth, the second pereopods are more developed, and the pleopods are fringed
with more setae than for larvae ofP, goniurus -The criterion of the lack of an outer seta on the maxillule
for distinguishing zoeae oi Pandalus from certain other Candea is shown to be invalid

In 1972 the National Marine Fisheries Service
began studies on the early life history of pandalid
shrimp in Alaska waters with the initial objective
of describing in detail laboratory-reared larvae of
each pandalid species previously unverified. Two
previous reports have described larvae of Pan-
dalus hypsinotus Brandt reared in the laboratory
(Haynes 1976) and P. goniurus Stimpson reared in
situ in Kachemak Bay, Alaska (Haynes 1978).
This report describes and illustrates each of the six
larval stages and the first juvenile stage of north-
ern shrimp, P. borealis KrOyer, and compares the
stages obtained from rearing in situ with descrip-
tions of pandalid shrimp larvae given by other
authors. A brief description of the second juvenile
stage is included.

MATERIALS AND METHODS

Rearing techniques were identical in all re-
spects to those described in an earlier report on P.
goniurus (Haynes 1978). Briefly, the technique
consists of obtaining Stage I larvae of known
parentage in the laboratory, then rearing the lar-
vae in flasks submerged at sea. Larvae from
plankton were also reared in flasks at sea in an
identical manner beginning with Stage I. Larvae
reared in flasks were compared with larvae from

'Northwest and Alaska Fisheries Center Auke Bay Laborato-
ry. National Marine Fisheries Service, NOAA, P.O. Box 155,
Auke Bay. AK 99821.

plankton for verification of sequence of stage and
larval morphology.

Because the paired appendages of the larvae are
symmetrical, only one member (the left) is figured.
An exception is the mandibles which are drawn in
pairs. Orientation of surface of appendages in the
figures is given in the figure legends. The figures of
the appendages are in part schematic and repre-
sent typical setal counts. Variability in setation or
segmentation of paired appendages, such as the
difference in number of carpal joints between the
left and right second pereopods in the megalopa, is
mentioned in the text. Carapace length refers to
the straight-line distance from posterior margin of
orbit to middorsal posterior margin of carapace.
Total body length refers to the distance from tip of
rostrum to posterior margin of telson, not includ-
ing telson spines. Terminology, methods of
measuring, techniques of illustration, and
nomenclature of gills and appendages follow
Haynes (1976). Comparison of larvae from
plankton with cast skins from flasks was facili-
tated by first clearing the larvae in W7c KOH. For
clarity, setules on setae are usually omitted but
spinulose setae are snown.

STAGE I ZOEA

Mean total length of Stage I (Figure lA) 6.7 mm
(range 6.5-7.3 mm; 25 specimens). Live specimens
characterized by orange color; conspicuous
chromatophores throughout cephalothorax re-

Manuscript accepted July 1978

FISHERY BULLETIN VOL 77. NO 1.1979

157

FISHERY BULLETIN VOL 77, NO 1

gion, especially in mouth parts; large
chromatophore near tip of antennal scale, at base
of telson, and at front of eye; smaller but distinct
chromatophores on maxillipeds; ventral surface of
each abdominal somite tinged orange; faint
greenish hue at base of pereopods. Rostrum slen-
der, spiniform, without teeth, about one-third

length of carapace, projecting horizontally or
slightly downward. Carapace with small, some-
what angular dorsal prominence at base of ros-
trum and smaller, rounded prominence near pos-
terior edge. These two prominences occur in all
zoeal stages. Pterygostomian spines present but
usually hidden by sessile eyes. Three or four mi-

0. 5 mm

Left

Right

0. 25 mm

158

HAYNES DESCRIPTION OF PA.MDAI.i'S ROREALIS LARVAE

nute spinules along ventral margin of carapace
immediately posterior to pterygostomian spine
I spinules not shown in Figure lA). These spinules
usually occur in all zoeal stages but may vary in
number from two to five not only between stages
but among individuals within a given stage.

ANTENNULE (Figure IB).— First antenna, or
antennule, consists of simple unsegmented tubu-
lar basal portion with heavily plumose seta termi-
nally and distal conical projection with four
aesthetascs: one long, one short, and two of inter-
mediate length.

0.25 mm

. 5 mm

0. 5 mm

K

0. 5 mm

Figure l. — Stage I zoea ofPandalus horealis: A, whole animal, right side; B. antennule, dorsal; C, antenna, ventral; D, mandibles (left
and right), posterior; E, maxillule. ventral; F, maxilla, dorsal; G, first maxiUiped, lateral; H, second maxilliped, lateral; 1, third
maxilliped, lateral; J, second pereopod, lateral; K, telson, dorsal.

159

FISHERY BULLETIN VOL 77. NO 1

ANTENNA (Figure IC).— Second antenna, or
antenna, consists of inner flagellum (endopodite)
and outer antennal scale (exopodite). Flagellum
unsegmented, slightly shorter than scale,
styliform, and tipped by spinulose spine. Antennal
scale distally divided into six joints (the two prox-
imal joints incomplete) and fringed with 19 heav-
ily plumose setae along terminal and inner mar-
gins; small seta occurs on outer margin at base of
joints and another proximally near outer margin.
Protopodite bears spinous seta at base of flagellum
but no spine at base of scale.

MANDIBLES (Figure ID).— Without palps in
this and all succeeding zoeal stages. Incisor pro-
cess of left mandible bears four teeth in contrast to
triserrate incisor process of right mandible. Left
mandible bears movable premolar denticle
(lacinia mobilis) whereas right mandible bears
two immobile premolar denticles. Truncated
molar process of left mandible bears subterminal
tooth that occurs throughout all zoeal stages.

MAXILLULE (Figure IE).— First maxilla, or
maxillule, bears coxal and basial endites and en-
dopodite. Coxopodite (proximal lobe) bears stout
seta near base, and eight spinulose spines termi-
nally. Basipodite (median lobe) bears nine
spinulose spines on terminal margin and large
setose seta proximally. Endopodite originates
from lateral margin of basipodite; bears three
terminal and two subterminal setae, three of them
sparsely plumose and remaining two spinulose.

MAXILLA (Figure IF). — Second maxilla, or
maxilla, bears platelike exopodite (scaphog-
nathite) with 11 long, evenly spaced plumose setae
along outer margin and one slightly longer and
thicker seta at the slightly expanded proximal
end. Endopodite gives indication of four partly
fused segments and bears nine large plumose
setae. Coxopodite and basipodite bilobed. Coxopo-
dite bears 21 setae, 4 on distal lobe and 17 on
proximal lobe. Basipodite bears eight setae on
each lobe. Five setae, three on coxopodite (one on
distal lobe and two on proximal lobe) and two on
distal lobe of basipodite, bear row of little spines
along entire length. An additional seta on proxi-
mal lobe of coxopodite is especially spinulose.

FIRST MAXILLIPED ( Figure IG i.— Most heav-
ily setose of natatory appendages. Protopodite
fully segmented; bears 7 setae on proximal seg-

ment and 18 slightly smaller setae on distal seg-
ment, 9 of them spinulose. Endopodite distinctly
four-segmented; setation formula 4, 2, 1, 4. Exopo-
dite a longer slender ramus segmented at base;
bears two terminal and three or four lateral nata-
tory setae. Epipodite a single lobe.

SECOND MAXILLIPED (Figure IH).-
Protopodite bisegmented; distal segment bears 10
sparsely plumose setae, no setae evident on prox-
imal segment. Endopodite distinctly five-
segmented, fourth segment expanded laterally;
setation formula 7, 3, 1, 2, 4. A seta on segments 1
and 5 of endopodite and three setae on protopodite
especially spinulose. Exopodite with 2 terminal
and 11 or 12 lateral natatory setae. No epipodite.

THIRD MAXILLIPED (Figure ID.—
Protopodite bisegmented; distal segment bears
four setae. Endopodite distinctly five-segmented;
nearly as long as exopodite; setation formula 4, .5,
1, 1,2. Exopodite with 2 terminal and 14 lateral
natatory setae. No epipodite.

PEREOPODS— Poorly developed, directed
under body somewhat anteriorly (Figure lA).
First three pairs biramous (second pereopod
shown in Figure IJ ), last two pairs uniramous and
slightly smaller than pairs 1-3.

PLEOPODS.— Absent.

TELSON (Figure IK).— Not segmented from
sixth abdominal somite; slightly emarginate pos-
teriorly; bears 1 + 1 densely plumose setae. Fourth
pair of setae longest, about one-half width of tel-
son. Minute spinules at base of each seta. Larger
spinules along terminal margin between bases of
four inner pairs and on setae themselves but
rarely on seventh pair. Uropods visible and en-
closed. No anal spine.

STAGE II ZOEA

Mean total length of Stage II (Figure 2 A) 7. .5
mm irange 6.7-8.2 mm; 25 specimens).
Chromatophore color and pattern essentially
identical to Stage I. except chromatophores larger
and color more pronounced, especially in mouth
parts. Rostrum still without teeth and not curved
downward as sometimes in Stage I. Carapace with
prominent supraorbital spine and clearly visible
antennal and pterygostomian spines. These three

160

HAYNES: DESCEUPTION OF PANDALUS BOREALIS LARVAE

spines persist through all remaining zoeal stages
Epipodite of first maxilliped slightly larger than
in Stage I but still not bilobed; pleurobranchiae
present as primordial buds.

ANTENNULE (Figure 2B).— Three-segmen-
ted; bears large outer and smaller inner flagellum

on terminal margin. Flagella not segmented.
Inner flagellum conical, bears one long spine ter-
minally. Outer flagellum bears two groups of aes-
thetascs: one group terminally consisting of eight
aesthetascs, two of them larger than remaining
six, and a pair of aesthetascs on inner margin. A
small budlike projection (not shown in Figure 2Bi

0.25 mm

Figure 2. — Stage II zoea ofPandalus borealis A, whole animal right side; B, antennule. ventral; C. antenna, ventral; D, mandibles
(left and right), posterior; E. maxillule. ventral: F, maxilla (exopodite and endopodite), dorsal.

161

FISHERY BULLETIN: VOL. 77, NO. 1

0. 5 mm

Figure 2. — Stage II zoea ofPandalus borealis: G, first pereopod, lateral; H, second pereopod, lateral; I. third pereopod. lateral; J, fourth

pereopod, lateral; K, fifth pereopod, lateral; L, telson, dorsal.

originates at base of flagella and bears five simple
setae. Proximal segment of antennule usually
bears five setae laterally near slightly expanded
base, three plumose setae laterally and distally,
about nine dorsally curving but smaller plumose
setae around distal joint, and large spine project-
ing slightly downward from ventral surface.

Second segment bears two plumose setae later-
ally and about six dorsally curving plumose
setae around distal joint. Third segment bears
seven plumose setae laterally, about four
of them originating ventrally, and three
simple setae laterally at base of outer fla-
gellum.

162

HAYNES DESCRIPTION OF PANDALUS BOREALIS LARVAP;

ANTENNA (Figure 2C).— Flagellum two-
segmented, still shorter than scale, styliform, and
tipped by two small simple setae and short spine.
Antennal scale fringed with 25 or 26 long, thin,
plumose setae along terminal and inner margins;
still has six joints distally but only the three most
distal joints complete. Protopodite bears minute
spine at base of scale in addition to conspicuous
spine at base of flagellum.

MANDIBLES (Figure 2Dl.— More massive
than in Stage I. Incisor processes of both mandi-
bles bear additional tooth. Both mandibles bear
additional denticles and molar processes more de-
veloped. Lacinia mobilis of left mandible consists
of single spinous denticle. Curved lip of trun-
cated end of molar process of right mandible more
developed than in Stage I.

MAXILLULE (Figure 2E).— Coxopodite bears
12-15 spines and row of fine hairs proximally;
spinules on two of the terminal spines of coxopo-
dite resemble a row of teeth. Basipodite and en-
dopodite essentially unchanged from Stage I, ex-
cept basipodite bears two additional spinulose
spines.

MAXILLA (Figure 2F, exopodite and
endopodite). — Exopodite similar in shape to Stage
I except more distinctly expanded proximally;
bears 17-19 marginal plumose setae in addition to
plumose seta at proximal end. Endopodite un-
changed from Stage I. Coxopodite bears 3 setae on
distal lobe and 17-19 on proximal lobe. Each lobe
of basipodite bears additional seta.

MAXILLIPEDS.— Essentially identical to
Stage I but bear additional setae as follows. On
first maxilliped, protopodite bears 8-10 setae on
proximal segment and 19-21 on distal segment;
endopodite bears 4, rarely 5, setae on proximal
segment; exopodite bears 7 or 8 natatory setae
rather than 5 or 6 as in Stage I; no change in
epipodite. On second maxilliped, protopodite bears
seta on proximal segment and 8-10 setae on distal
segment; exopodite bears 14 lateral natatory setae
in addition to the 2 terminal setae. On third maxil-
liped, endopodite bears additional seta terminally
on dactylopodite, 2 additional setae on propodite,
and additional seta on carpopodite, setation for-
mula 5, 7, 3, 1, 2; exopodite bears 16 lateral nata-
tory setae in addition to 2 terminal setae. No gill
buds on second or third maxillipeds.

FIRST PEREOPOD (Figure 2G).— Protopodite
bears three setae. Endopodite functionally de-
veloped; five-segmented, terminating in simple
conical dactylopodite; setation formula 5, 3, 2. 2, 2.
Exopodite, longest among pereopods, bears 2 ter-
minal and 14 lateral natatory setae.

SECOND PEREOPOD (Figure 2H),—
Protopodite bears two setae. Endopodite similar to
first pereopod except shorter; setation formula 4,
3, 1, 1, 2. Exopodite bears 2 terminal and 13 or 14
lateral natatory setae.

THIRD PEREOPOD (Figure 21).— Protopodite
bears two setae. Endopodite one-fourth to one-
third longer than exopodite; dactylopodite slightly
longer than in first two pereopods; setation for-
mula 3, 4, 2, 1, 2. Exopodite noticeably shorter
than exopodites of first and second pereopods and
bears 2 terminal and 9 or 10 lateral natatory setae.

FOURTH PEREOPOD (Figure 2J).—
Endopodite five-segmented but still poorly de-
veloped and directed under body somewhat an-
teriorly as in Stage I (Figure 2A); dactylopodite
and propodite bear two setae and three setae, re-
spectively. No exopodite.

FIFTH PEREOPOD (Figure 2K).— Similar to
fourth pereopod but shorter and dactylopodite
tipped with single seta. No exopodite.

PLEOPODS (Figure 2A).— Present as distinct
buds.

TELSON (Figure 2L).— Similar in shape to
Stage I but distinctly jointed from sixth abdominal
somite; bears 8 4-8 densely plumose setae.
Uropods still enclosed. Anal spine present but mi-
nute.

STAGE III ZOEA

Mean total length of Stage III 9.5 mm (range
9.0-10.0 mm; 10 specimens). From this stage on,
zoeae gradually become more orange and color
pattern not useful in identifying a given stage.
Rostrum (Figure 3A) projects horizontally but
curves slightly downward at tip; bears one or two
teeth at base. Epipodite of first maxilliped bilobed;
pleurobranchiae present as small buds.

ANTENNULE (Figure 3B, inner and outer

163

FISHERY BULLETIN: VOL, 77, NO 1

flagella). — Flagella not segmented. Inner flagel-
lum about one-half length of outer flagellum, bear-
ing stiff seta at base of terminal spine. Outer
flagellum bears four long and two shorter aes-
thetascs terminally and two groups of three aes-
thetascs each proximally.

ANTENNA (Figure 3C).— Flagellum eight-
segmented, about equal in length to scale, tipped

by three short setae and remnant of terminal
spine. Antennal scale narrower than in Stage II
and fringed with about 30 plumose setae; two
complete joints at tip. Spine on protopodite at base
of scale considerably larger than in Stage II.

MAXILLIPEDS.— Change in form and setation
of maxillipeds from Stage III on is slight and con-
sists primarily of second maxilliped becoming

0. 5 mm

0. 5 mm

164

HAYNES: DESCRIPTION OF PANDALUS BOREALIS LARVAE

curved as in adult and its propodite slightly vi-id-
ened, third maxilliped becoming shaped as in
adult, and natatory setae on exopodites of second
and third maxillipeds increasing in number to
usually 20 in Stage V.

FIRST PEREOPOD ( Figure 3D ).— Has begun to
acquire adult shape, particularly in widened pro-
podite and carpopodite segments.

SECOND PEREOPOD (Figure 3E i.— Similar to
Stage II except distal joint of propodite projects
slightly anteriorly.

THIRD, FOURTH (Figure 3F), AND FIFTH
PEREOPODS.— Endopodites similar; like first
pereopod have begun to acquire adult shape, espe-
cially in lengthened dactylopodite and widened
propodite. Ischiopodite articulates somewhat lat-
erally with meropodite.

PLEOPODS (Figure 3G, second pleopod).—
Bilobed, unsegmented. and without setae.

TELSON (Figure 3H).— Endopodite not fully
developed; about one-third length of exopodite and
bearing several setae along lateral and posterior
margms. Uropods free. Anal spine clearly visible.

0. 5 mm

Figure 3. — Stage III zoea of Pandal us borealis: A, whole ammal, right side; B. antennule i inner and outer flagella). ventral; C,
antenna, ventral; D. first pereopod. lateral. E. second pereopod, lateral; F. fourth pereopod, lateral; G. second abdominal somite and
pleopod, right side; H, telson, dorsal.

165

FISHEKY BULLETIN: VOL 77. NO. 1

STAGE IV ZOEA

Mean total length of Stage IV 13.0 mm (range
12.6-13.2 mm; 10 specimens). Rostrum (Figure
4A) bears four to eight but usually six teeth dor-
sally, no teeth ventrally; tip not bifid. No change in

epipodite of first maxiliiped or pleurobranchiae
except slight increase in size. Epipodite on second
maxiliiped present as small bud. No mastigobran-
chiae.

ANTENNULE (Figure 4B, inner and outer

0. 5 mm

0. 5 mm

0. 5 mm

0. 5 mm

FK;l;ke 4. — Stage IV zoea nf Pandalus bumaUs: A, rostrum, right side; B. antennule (inner and outer flagella), ventral; C. antenna,
ventral; D, first pereopod i distal segments only), lateral; E, second pereopod (distal segments only), lateral; F, second abdominal somite
and pleopod, nght side; G, telson. dorsal.

166

HAYNES DESCRIPTION OF PA.VD.AZ.C.S BOREALIS LARVAE

flagellai. — Flagella two-segmented. Inner flagel-
lum nearly as long as outer flagellum. Outer
flagellum bears four aesthetascs and two spines
terminally and three groups of three aesthetascs
each on proximal segment.

ANTENNA (Figure 4C ). — Flagellum 15-
segmented; 1.5-2 times length of scale, extending
past tips of plumose setae fringing antennal scale.
Antennal scale without joints at tip. Other than
increase in size, changes in antennal scale from
Stage IV onward are negligible.

FIRST PEREOPOD (Figure 4D).— Distal joint
of propodite projected anteriorly and tipped with
small spine.

SECOND PEREOPOD (Figure 4E).— Distal
joint of propodite projected anteriorly to about
one-half length of dactylopodite; projection tipped
by two spines, one terminal and other subterminal
and much shorter. Dactylopodite bears one termi-
nal spine and two considerably shorter subtermi-
nal spines.

PLEOPODS (Figure 4F, second pleopod).—
Segmented; length of second pair of pleopods about
one-half height of second abdominal somite.
Exopodite usually bears one to four small setae
terminally and endopodite sometimes bears single
seta terminally. Appendices internae not present.

TELSON (Figure 4Gi.— Endopodite of uropod
about two-thirds length of exopodite and fringed
with about 20 setae. Lateral margins of telson
nearly parallel but slightly divergent posteriorly
and bear two spines each. Posterior margin still
slightly emarginate; bears 6 -(- 6 spines, the out-
ermost (sixth) pair usually without spinules.

STAGE V ZOEA

Mean total length of Stage V 16.0 mm (range
15.2-17.1 mm; 10 specimens). Rostrum (Figure
5A) with 9-12 dorsal teeth, bifid tip, and usually 4.
but sometimes 5, partially developed ventral teeth.
Pleurobranchiae curve somewhat anteriorly and
edges minutely lobulate. Mastigobranchiae occur
as minute buds on protopodite of third maxilliped
and pereopods 1-4.

ANTENNULE (Figure 5B, flagella only).—
Inner flagellum four-segmented. Outer flagellum

four- or five-segmented; bears six groups of three
aesthetascs each. Each segment bears at least one
seta but number and location of setae somewhat
variable.

ANTENNA (Figure 5C).— Flagellum 2-3 times
length of scale.

FIRST PEREOPOD (Figure 5D, distal segments
only). — Projection of propodite at least one-half
length of dactylopodite; bears two small spines,
one terminally and one subterminally. Dactylopo-
dite bears small spine subterminally in addition to
terminal spine.

SECOND PEREOPOD (Figure 5E, distal seg-
ments onlyl. — Chela well formed. Terminal spine
of propodite shorter and stouter than in Stage IV.
Dactylopodite bears five spines, the distal two
especially stout. Carpopodite usually at least par-
tially segmented.

PLEOPODS (Figure 5F, second pleopod).—
Second pair of pleopods about equal in length to
height of second abdominal somite; outer flagel-
lum fringed with 11 or 12 plumose setae, inner
flagellum with about 8 setae. Appendices internae
usually present on pleopods 2-5; tips sometimes
bear a few cincinnuli.

TELSON (Figure 5G). — Lateral margins of tel-
son essentially parallel and bear two spines each.
Posterior margin straight or slightly emarginate,
bearing 6 + 6 spines. Uropods similar in shape to
adult; no evidence of transverse hinge of exopo-
dite.

STAGE VI (MEGALOPA)

Mean total length of Stage VI 18.5 mm (range
17.4-20.2 mm, 5 specimens). Rostrum (Figure 6A)
shaped as in adult; bears 13-15 dorsal teeth in
addition to distinct bifid tip, and 6 or 7 distinct
ventral teeth. Usually one or two setae between
dorsal teeth. Carapace lacks supraorbital spine.
Exopodites on maxillipeds and pereopods 1-3 re-
duced. Pleurobranchiae and mastigobranchiae
shaped as in adult. Inner and outer flagella of
antennule eight- to nine-segmented and five-
segmented, respectively. Flagellum of antenna
about 6 times length of antennal scale. Mandibles
still without palps. Chaelae of first and second
pereopods shaped as in adult; carpal joints of left

167

FISHERY BULLETIN: VOL 77. NO 1

0. 5 mm

Figure 5. — Stage V zoea of Pandal us borealis: A, rostrum, right side; B.antennulelflagellaonlyl, ventral; C, antenna, ventral; D, first
pereopod (distal segments only), dorsal; E, second pereopod idistal segments onlyi, dorsal; F. second abdominal somite and pleopod.
right side; G. telson, dorsal.

and right second pereopods 20-25 and 10-13, re-
spectively. Pleopodal setae extend along entire
lateral margins of both flagella; tips of appendices
internae bear several distinct cineinnuli. Length
of second pair of pereopods, excluding setae, 1.5-2
times height of second abdominal segment. Telson
(Figure 6B) shows, for first time, shape and spina-

168

tion similar to adult; lateral margins converge
posteriorly but widen slightly at junction with
posterior margin; typically four spines on each
lateral margin but in this stage and Stages VII
and VIII one lateral spine often lacking. Posterior
margin of telson rounded but not as much as in
Stage VII; bears 3 + 3 stout spines and sometimes

HAYNES DESCRIPTION OF PA.WDALUS BOREALIS LARVAE

u

J

. 5 mm

Figure 6. — Stage VI imegalopal of Pandalus bnrealis: A. ros-
trum, right side; B. t«lson. dorsal.

remnants of a spine or two from Stage V. Trans-
verse hinge of exopodite of uropod complete.

STAGES VII AND VIII (JUVENILES)

Mean total length of Stage VII (first juvenile)
18.4 mm (range 15.1-21.0 mm; 5 specimens). Usu-
ally two setae between most rostral teeth.
Carapace without supraorbital spine. Arthro-
branchiae on third maxilliped and pereopods 1-4
present as minute buds. Mandibular palp present
for first time; three-segmented. Inner and outer
flagella of antennule each 11- to 13-segmented.
Exopodites on maxillipeds and pereopods 1-3 rem-
nant. Third abdominal somite sometimes bears
minute spine on middorsal posterior margin. Car-
pal joints of left and right second pereopods 28-30
and 14-17, respectively. Lateral margins of telson

(Figure 7) typically bear 5 + 5 spines; posterior
margin rounded as in adult.

Mean total length of Stage VIII (second
juvenile) 21.6 mm (range 19.0-23.6 mm; 8 speci-
mens). Morphological differences between Stages
VII and VIII slight. Most notable features of Stage
VIII: at least three or four setae between most
rostral spines; complete lack of exopodites on third
maxilliped and pereopods 1-3; inner and outer
flagella of antennule each 15- to 16-segmented;
lateral margins of telson typically bear 6 + 6
spines.

COMPARISON OF LARVAL STAGES

WITH DESCRIPTIONS BY

OTHER AUTHORS

The first description of larvae ascribed to Pan-
daliis horealiti was given by Sars ( 1900), based on
specimens collected from plankton. Berkeley
(1931) showed that Sars' larvae could not be P.
borealis; almost simultaneously Lebour (1930)
showed that they were Caridion gordoni (Bate).
Sars' "post-larval" specimen, however, is consid-
ered by both Lebour and Berkeley to be correctly
identified as P. borealis . As far as can be compared,
my Stage VI (megalopa) and Sars' "post-larval"
specimen are essentially identical except for the

I' n \

L

J

0. 5 mm

Figure 7.— Stage VII (first juvenilel of Pandalus borealis: tel-
son, dorsal.

169

FISHERY BULLETIN; VOL

rostral tip, which in my larva is bifid but in Sars' is
styliform, and the chela of the first pereopod,
which is completely developed in my larva but not
in Sars'.

Stephensen ( 1912) described zoeal Stages I to V
from plankton that he provisionally identified as
"P. propinquus (?)" and Stage III zoeae (1916) as
"Spirontocaris-\ar\a No. 4." Berkeley (1931) not-
ed the close similarity of the "P. propinquus (?)"
specimens to zoeae of P. borealis from British Co-
lumbia waters. Stephensen (1935) later decided
that both "P. propinquus (?)" and "Spirontocaris-
larva No. 4" were actually zoeae of P. borealis. He
also compared his zoeae with fragments of a
specimen identified by Kr0yer as Dymas typus and
decided Kr0yer's specimen was a Stage IV zoea of
P. borealis.

Comparing the description and figures of
Stephensen's ( 1912) zoeae and mine in general for
each stage, my zoeae are slightly more advanced
than Stephensen's. In my Stage I zoeae the anten-
nal scale bears 19 plumose setae; the basipodite
and coxopodite of the maxillule bear 9 + 1 and 9
spines, respectively; the endopodite of the first
maxilliped is segmented; and the exopodites of
maxillipeds 1, 2, and 3 bear 6. 14, and 16 natatory
setae, respectively. In Stephensen's Stage I zoeae
the antennal scale bears only eight or nine
plumose setae; the basipodite and coxopodite of
the maxillule bear five and six spines, respec-
tively; the endopodite of the first maxilliped is not
segmented; and the exopodites of maxillipeds 1, 2,
and 3 bear 4, 10, and 10 natatory setae, respec-
tively. In Stage II, the relative difference in
number of setae and spines between my zoeae and
Stephensen's remains essentially the same, except
in my zoeae the exopodites of pereopods 1, 2, and 3
bear 16, 16, and 12 setae, respectively, whereas in
Stephensen's zoeae they each bear 18 setae. In
Stage III, the rostrum of my zoeae bears only a
single tooth and the antennal flagellum is eight-
jointed, but in Stephensen's zoeae the rostrum
bears as many as three teeth and the antennal
flagellum is notjointed. In Stage IV, the rostrum of
my zoeae bears six or seven teeth, the antennal
flagellum is 15-segmented, and the telson bears
eight pairs of spines whereas in Stephensen's
zoeae the rostrum bears only four teeth, the an-
tennal flagellum is still unsegmented, and the tel-
son bears only seven pairs of spines. In Stage V,
the most obvious difference is that the pleopods
are segmented in my zoeae but not in Stephen-
sen's.

In his 1916 report, Stephensen described an ad-
ditional larva which he considered the sixth stage
oi P. propinquus G. O. Sars; later (1935) he decided
it was P. borealis. According to Stephensen, this
stage closely resembles his Stage V zoeae, differ-
ing primarily in the left second pereopod being con-
siderably longer than the right, and, for both sec-
ond pereopods, the joint at the distal end of the
carpopodite being complete. In my larvae, mor-
phological change from Stage V to Stage VI is
sufficiently pronounced that I consider the sixth
stage to be the megalopa. If Stephensen was cor-
rect in assuming his specimen to be a sixth stage
zoea, then P. borealis in Greenland waters has at
least six zoeal stages compared with only five zoeal
stages in Alaska waters.

In her classic study of pandalid larvae from
British Columbia waters, Berkeley (1931) de-
scribed and figured P. borealis Stage I zoeae reared
in the laboratory and Stages II-VI collected from
plankton. Her larvae follow a pattern of develop-
ment similar to my larvae but each stage is less
well developed. For instance, she described the
antennal flagellum in her Stage I zoeae as tipped
by a simple seta whereas in my zoeae it is tipped by
a spinulose spine, and she neither figured nor de-
scribed the spinous seta which my zoeae bear on
the protopodite at the base of the flagellum. Also,
the exopodite of the maxilla of her Stage I zoeae
bears 8-10 long simple setae and has no trace of a
proximal expansion whereas in my zoeae the
exopodite of the maxilla bears 11 long plumose
setae as well as one longer, thicker seta at the
proximal end which is slightly expanded. In Stage
II, the outer flagellum of the antennule of Berke-
ley's zoeae is figured as bearing only three aes-
thetascs distally whereas my zoeae bear eight. The
proximal expansion of the exopodite of the maxilla
is "just appearing" in Berkeley's Stage II but in
mine it is distinctly expanded. Moreover, she de-
scribed the telson as being still indistinctly seg-
mented from the sixth abdominal somite but in my
zoeae it is always distinctly segmented at Stage II.
Berkeley's Stage III zoeae are essentially identical
to mine as far as can be determined from her de-
scription. Her Stage IV zoeae have four small
teeth at the base of the rostrum, the pleopods are
without joints, and there is no epipodite on the
second maxilliped. In my Stage IV zoeae, the ros-
trum usually has six teeth, the pleopods are
jointed, and an epipodite occurs on the second
maxilliped. In Stage V, the rostral tip of Berke-
ley's zoeae is still styliform. There is no evidence

170

HAYNES: DESCRIPTION OF PANDALUS BOREALIS LARVAE

from either her description or figure of ventral
teeth on the rostrum, and the pleopods have not
yet developed appendices internae. In my Stage V
zoeae the rostral tip always bears at least a pro-
tuberance indicative of the bifid tooth, and
pleopods 2-5 bear at least partially developed ap-
pendices internae. In contrast to my Stage VI, the
megalopa, Berkeley's Stage VI is still typically
zoeal: there is still no mention of ventral rostral
teeth, the carapace still bears a supraorbital spine,
the carpopodites of the second pereopods are not
segmented, and the telson bears three pairs of
lateral spines (not including the sixth terminal
pair) and terminal setal pairs 2-4 have begun to
degenerate.

Berkeley (1931) also mentioned a P. borealis
larva she obtained from plankton that, according
to her. corresponds to the sixth stage of P. danae
Stimpson and is similar to that described by Sars
(1900) as the "post-larval" stage of P. borealis.
Berkeley's sixth stage and Sars' "post-larval"
stage are typically nonzoeal as indicated by the
lack of supraorbital spines, segmentation of the
carpopodites of the second pereopods, degenera-
tion of the pereopodal and third maxilliped exopo-
dites, and the typically adult shape and spination
of the telson. Because this stage would be at least
the seventh stage, it appears that P. borealis in
British Columbia waters, as well as Greenland
waters (Stephensen 1916), has at least six zoeal
stages compared with only five zoeal stages in
Alaska waters.

The preceding comparisons show that Berke-
ley's zoeae were less well developed at each given
stage than mine and an additional stage or two
was probably necessary for her zoeae to reach the
megalopa stage. An apparent contradiction to this
delayed development is the lack of segmentation
of the antennal scale in the early stages of Berke-
ley's zoeae. As shown by Haynes (1976), however,
Berkeley was mistaken in this regard and her
specimens undoubtedly possessed a segmented
scale in the early stages.

The only other description of larvae of P.
borealis known to me is that of Kurata ( 1964) who,
like Berkeley 1 1931 ), obtained Stage I zoeae in the
laboratory from known parentage but Stages
II-VII from plankton. Kurata's zoeae are essen-
tially identical to mine through Stage V, except
the rostrum of Kurata's Stage V zoeae is iden-
tical to the rostrum of my Stage IV zoeae. Kurata's
Stage VI corresponds to my Stage V, but his Stage
VII possesses characteristics intermediate be-

tween my Stages V and VI. For instance, in Kura-
ta's Stage VII the exopodites on pereopods 1-3 and
the third maxilliped have not begun to degenerate
nor are the carpopodites segmented whereas in my
Stage VI (megalopa) the exopodites on pereopods
1-3 and the third maxilliped are reduced and the
carpopodites of the left and right second pereopods
are segmented. Also, the lateral spination and
shape of the telson of Kurata's Stage VII are typi-
cal of postzoeae but posteriorly the telson bears
6 + 6 spines, a typically zoeal characteristic. By
studying Stage VII individuals just prior to molt-
ing, Kurata found that Stage VIII individuals pos-
sessed a distinct mandibular palp and degenera-
tion of posterior telson spines 2-4. He concluded
that Stage VII was the last zoeal stage and Stage
VIII the first postzoea, or megalopa.

According to Lebour (1930). the lack of an outer
seta on the maxillule in zoeae of Pandalus is one
criterion for distinguishing this genus from cer-
tain other Caridea. Pike and Williamson (1964),
however, found the seta consistently present in
early stages of British species of Pandalus. Oc-
currence of the seta in Stage I zoeae has been
reported by Gurney ( 1942) for Pandalus montagui
Leach and P. stenolepis Rathbun; by Kurata
(1955, 1964) for P. borealis and P. kesslen Czer-
niavski; and Modin and Cox ( 1967) for P.jordani
Rathbun. I have consistently found the seta in the
early stages of P. hypsinotus, P. goniurus, and P.
borealis. Lebour's suggestion that the lack of the
seta is a distinguishing criterion for zoeae of Pan-
dalus should, therefore, be disregarded.

In addition to P. borealis. larvae have been de-
scribed, at least in part, for nine other species of
pandalids from the North Pacific Ocean: P.
goniurus, P. jordani, P. platyceros Brandt, P.
danae, P. kessleri, P. hypsinotus, P. stenolepis,
Pandalopsis dispar Rathbun, and P. coccinata
Urita. Of these nine species, larvae of Pandalus
stenolepis, P. jordani. and P. goniurus are most
like larvae of P. borealis, being characterized by
exopodites on pereopods 1-3 rather than only on
pereopods 1 and 2 and by poorly developed
pereopods in Stage I. Zoeae of P. stenolepis were
described by Needier ( 1938). Based on her descrip-
tions, zoeae of P. stenolepis are readily distin-
guished from zoeae of P. borealis by 1) the shape
and spination of the rostrum, which in Stage I P.
stenolepis is about as long as the carapace and
projects upward rather than downward as in P.
borealis, and 2) the fringed posterior edge of the
abdominal somites and the serrated margins of

17]

FISHERY BULLETIN VOL 77. NO. 1

the carapace, both of which persist to Stage V in P.
stenolepis but never occur in P. borealis.

Larvae of P. jordani have been described from
specimens reared in the laboratory. Compared
with development of similar species, Modin and
Cox (1967) and Lee (1969) obtained more stages
(11-13 and at least 8, respectively) than expected
for larvae of P.jordani from plankton. Because of
the possibility of these extra stages, only Stage I
zoeae of P. borealis and P. jordani can be com-
pared. Upon hatching, zoeae of P. borealis are
slightly more developed than zoeae of P. jordani.
For instance, in Stage I P. jordani, the exopodites
of maxillipeds 1,2, and 3 bear 4, 9-11, and 11 or 12
natatory setae, respectively; the left mandible
bears no lacinia mobilis; the basipodite of the
maxillule bears six spines terminally; and the
scaphognathite of the maxilla bears seven to nine
setae along its outer margin. In Stage! P. borealis,
maxillipeds 1, 2. and 3 bear 5 or 6, 13 or 14, and 16

natatory setae, respectively; the left mandible
bears a single lacinia mobilis; the basipodite of the
max