Systematics, distribution, and abundance of the epiplanktonic squid

98 Pages·2004·1.9 MB·English

UC San Diego
Bulletin of the Scripps Institution of Oceanography
Title
Systematics, distribution, and abundance of the epiplanktonic squid (Cephalopoda,
Decapoda) larvae of the California Current, April, 1954- March, 1957
Permalink
https://escholarship.org/uc/item/09g2j7s8
Authors
Okutani, Takashi
McGowan, John A.
Publication Date
1969-01-08

Peer reviewed
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University of California
SYSTEMATICS, DISTRIBUTION, AND ABUNDANCE OF
THE EPIPLANKTONIC SQUID (CEPHALOPODA,
DECAPODA) LARVAE OF THE CALIFORNIA CURRENT,
APRIL, 1954–MARCH, 1957
BY
TAKASHI OKUTANI and JOHN A. McGOWAN
BULLETINOFTHESCRIPPSINSTITUTIONOFOCEANOGRAPHY
UNIVERSITYOFCALIFORNIA,SANDIEGO
LAJOLLA,CALIFORNIA
Volume14
UNIVERSITYOFCALIFORNIAPRESS
BERKELEYANDLOSANGELES
1969
SYSTEMATICS, DISTRIBUTION, AND ABUNDANCE OF
THE EPIPLANKTONIC SQUID (CEPHALOPODA,
DECAPODA) LARVAE OF THE CALIFORNIA CURRENT,
APRIL, 1954–MARCH, 1957
SYSTEMATICS, DISTRIBUTION, AND ABUNDANCE OF
THE EPIPLANKTONIC SQUID (CEPHALOPODA,
DECAPODA) LARVAE OF THE CALIFORNIA CURRENT,
APRIL, 1954–MARCH, 1957
BY
TAKASHI OKUTANI and JOHN A. McGOWAN
UNIVERSITYOFCALIFORNIAPRESS
BERKELEYANDLOSANGELES
1969
BULLETINOFTHESCRIPPSINSTITUTIONOFOCEANOGRAPHY
UNIVERSITYOFCALIFORNIA,SANDIEGO
LAJOLLA,CALIFORNIA
EDITORS:G.O.S.ARRHENIUS,C.S.COX,E.W.FAGER,C.H.HAND
TODDNEWBERRY,M.B.SCHAEFER
Volume14
ApprovedforpublicationApril19,1968
IssuedJanuary8,1969
Price,$3.00
UNIVERSITYOFCALIFORNIAPRESS
BERKELEYANDLOSANGELES
CALIFORNIA
UNIVERSITYOFCALIFORNIAPRESS,LTD.
LONDON,ENGLAND
[CONTRIBUTIONFROMTHESCRIPPSINSTITUTIONOFOCEANOGRAPHY,NEWSERIES]
©1969BYTHEREGENTSOFTHEUNIVERSITYOFCALIFORNIA
PRINTEDINTHEUNITEDSTATESOFAMERICA
CONTENTS
Introduction 1
Acknowledgments 1
MethodsofCollection 1
Results 7
SystematicsandDescriptionsofLarvalStages 7
1.LoligoopalescensBerry 8
2.AbraliopsisfelisMcGowanandOkutani 12
3.PterygioteuthisgiardiFischer 15
4.Octopodoteuthopsissp. 21
5.Onychoteuthisbanksii(Leach) 24
6.Gonatusfabricii(Lichtenstein) 26
7.Calliteuthis(Meleagroteuthis)heteropsisBerry 31
8.Ctenopteryxsicula(Verany) 33
9.Rhynchoteuthionlarvae 35
10.Chiroteuthisveranyi(Ferrusac) 38
11.Pyrgopsispacificus(Issel) 39
12.Teuthoweniamegalops(Prosch) 43
13.HelicocranchiapfefferiMassy 45
14.Liguriellasp 46
DistributionandAbundance 49
Generalcomposition 50
Seasonalabundanceandpopulationpatterns 56
Summaryanddiscussion 75
OceanographicRelationships 79
Appendix 83
LiteratureCited 86
[v]
SYSTEMATICS, DISTRIBUTION, AND ABUNDANCE OF
THE EPIPLANKTONIC SQUID (CEPHALOPODA,
DECAPODA) LARVAE OF THE CALIFORNIA CURRENT,
APRIL, 1954–MARCH, 1957
BY
TAKASHI OKUTANI* and JOHN McGOWAN
INTRODUCTION
OurKnowledgeofthebiologyofoceaniccephalopodsisextremelylimited. Thepopulationsizes,distribution
patterns, breeding seasons, life histories, and growth rates are virtually unknown. In view of the fact that
these organisms are undoubtedly abundant and ecologically important, both as predators and prey, this state
ofignoranceisunfortunate. Partofthereasonforthislackisattributabletothegreatdifficultyofadequately
sampling the adults. The larvae and some juveniles, however, can be caught, in the types of plankton nets
and trawls generally in use. Therefore the possibility exists that the times and places of spawning, and the
developmental history of many species, may be determined from zooplankton surveys. Using this approach
presupposesthatasufficientlyextensiveareaissurveyedandthatthesamplingisintensiveinbothspaceand
time. It is also necessary that enough specimens of the adults and intermediate-sized ranges be available
for accurate identification of the larvae. This is best done by tracing the morphological changes through
progressivelysmallerindividuals.
The Marine Life Research Group at Scripps Institution of Oceanography (SIO) has available a very large
collectionofzooplanktonsamplestakenbytheCaliforniaCooperativeOceanicFisheriesInvestigationsinthe
CaliforniaCurrent. Thisprogramhassurveyedalargeportionofthiscurrentsystembymonthlycruisesfora
periodoftenyears. Itisfromthesesamplesthatthedatainthisreportarederived.
ACKNOWLEDGMENTS
WewishtoacknowledgethecooperationoftheBureauofCommercialFisheriesatLaJollafortheirassistance
insortingthecephalopodlarvaefromthesesamples.TheMarineLifeResearchProgramhasprovidedmaterial
assistance. AportionoftheworkhasbeensupportedbytheNationalScienceFoundationunderthetermsofa
grant(G-19417). MissVernieFraundorfhasrenderedvaluableaidinthepreparationofthemanuscript.
Whilealltheworkinthisreportwasdonejointly,thesystematicssectionisprimarilythatofT.Okutani,and
theothersectionsthatofJ.A.McGowan.
METHODS OF COLLECTION
The cephalopod larvae described in this report came from zooplankton collections made in the California
CurrentbytheCaliforniaCooperativeOceanicFisheries
*TokaiRegionalFisheriesResearchLaboratory,Tokyo.

[1]
2
Investigations (CalCOFI) during the years 1954, 1955, 1956, and 1957. Throughout this program only one
typeofplanktonnetwasused: anetwithamouthdiameterof1meterandalengthof5meters. Itisconicalin
shapeandmadeofheavyduty, grit-gauzesilk, 0.65mmbetweenthethreads. Ahlstrom(1948)haspublished
anillustrationanddescriptionofthisnet.
Thevolumeofwaterfilteredbythenetwasmeasuredbyaflowmetersuspendedinitsmouth. Theamount
ofwaterfilteredcanbederivedfromtheflow-meterreadingsbythemethoddescribedbyAhlstrom(1948).For
thesamplesusedin
thisreportthevolumefilteredbythenetsrangedbetween450m3and950m3withoccasionalfiguressomewhat
higherorlower.
Themethodoftakingthetowswasalsothesameduringtheentirecourseofthissurvey. Obliquetowswere
takentoanaveragedepthof140meterswithoccasionaltowsgoingsomewhatdeeperorshallowerthanthis.
The speed of the ship and the net through the water was approximately 1.5 knots (75 cm/sec). The original
dataonvolumesofwaterfiltered,depthoftows,andtimeoftowsusedinthisstudyhavebeenpublished(So.
Pac. Fish. Invest.,1955,1956;Thrailkill,1957).
Thestationpositionsandstationnumbersareillustratedinfigure1whichshowsthecompletestationpattern
oftheCalCOFIprogram. Noneoftheindividualcruisesusedinthisstudycoveredsolargeanarea. Theextent
anddistributionofthestationpatternusedheremaybeseeninfigures20to22. The28cruisesstudiedtook
3,895planktontows,allofwhichwereexamined.Ofthisnumber,1,240containedsquidlarvae.Table1shows
byyearandmonththenumberofstationsoccupied.
It is the purpose of this report to present quantitative estimates of the distribution and abundance of larval
squid,and,sincethissamplingprogramwas
Fig. 1. OverallstationplanoftheCaliforniaCooperativeOceanicFisheriesInvestigations. Thenumbers
representstationnumbers. Theseremainedthesamethroughoutthesurveys.