The Biology of Pelagic Shrimps in the Ocean

THE BIOLOGY OF PELAGIC SHRIMPS IN THE OCEAN Occnn I i ~ s ~ a r rI h~ t s t iute t Ti~~iverui/y of Tok!jo. Nnkuno. Tokgo. J n p n

.

.

Introt111et~io11 . . .. .. .. .. .. Qnric.rnl Fo~tt~urea of l'okgie Shrirnpu . . . . .. Biomaaw . . .. .. . . .. .. .. Vtwt.icnl I)i~t.riln~t. iorl and Holntotl I'rohlrtnl~. . . A . G o ~ ~ e rVortical el I)intribut.io~~ . . .. B . I)iurnal Migmtit>n . . .. .. ..
.

.

.

.

.

.

.

.

1. I.\TROI)U(~TION Since t.tie timc of the Challt*ngerF:xpc!dition in 1873-76. the occurrence of bright red pelagio shrimps in the mid and deep waters of the ocean hlis been known . Recent ly HI uch attention has been paid to their role in the productivity of the ocean . I'ossibly. the feeding of shrimp8 links zooplankton and lusgc l~riirnalsof the higher trophic levels in the food chains a ~ i dtra11sportsorganic matter produced in the upper layers to the lower l q e r s t'hrough vertical migrations. Our knowledge of such problems is limited due to the lack of basic information on the biology and ecology of pelagic shrimps . In oceanic waters pelagic shrimps are mostly distributed in water below 160 m depth by day . Usually. they are taken only in small 233

iiciinI)(w i n ordiiiury plaiiloryof predominant species. Siiice 1!)63 thc staff of the plankton laboratory of the Ocean Itesearc*h I nstitute has conducted an extensive plankton survey ilsing the 0141-net and ZKMT. The survey covers a wide area in the north-western Pacific Ocean in depths ranging from the surface to about 1 500 in. During the course of this investigation, attention has been paid to the analysis of the life of pelagic shrimps as well as other midwater animals, and we have obtained much information on their biology although somc results have not been published as yet. Such circunistmces prompttad me to summarize our present knowlectgc of thcb biology i m l c~cologyof pelagic shrimps, and review all nvidable previoiis litcwrturc with o u r data. [ hope this study will be 1rsefi11in fiiturcl invrstigatiotis 01' the shrimps in the ocean.

11. (:ENERAL F K A T U ~o~wI G YEI,A(XIC S SHRIMPS Tlic iiuiiibcv- of spwics of tlwapo(l crnstiwwxi which pans their permtuiwt life iii thc prlagicb phiis(. is rrhtivctly small cornpard with the richiiesx o f the bcnthic. fbrms. Systomatically, a11 reprt*sentative genera belong to the NiLt,ant i i i hlacriira. The number of pelagic species is less than 210 out of 21 total of about 1 940 species in this supttrscction, and most of these are inclrided in the subfamilies Aristeinae and Sergestinao of the section Penaeidea or the families Pasiphaeidae, Oplophoridae tuid Pandalidae of the section Caridea. Table I show8 major genera and representative species of pelagic shrimps. For some species, such as Sympasiphaea imperialis Terao and Eupasiphae gibsi Wood-Mason, which are rarely found in deep water, i t is uncertain whether thcy have a true pelagic mode of life. Several benthic shrimps arv known t,o be distributed in midwater at night, although they live on or in tht. bottom sediments by day. It, is probable that the species in such geiiera iis Ariatapus, Aristeomorpha and Benthcscymus of the

'1'1114: 1 4 1 0 1 , 0 ( 1 ~

ow

I'EI.A(:I(' SHRIMPS

I N 'L'HE IAN

235

subfanlily Arist,eini~c,occ-urring on thr. cotltintmtal slopo or its vicinity, have both peli~gicfiand benthi(* phases in fhcir adult life. Similarly, i ~ n dhcsvy-hodit~ifoi-rns in the genera E'asiphaea, sonle of tlir 1i~1.g~ I'arapasiphw, Acnntlbeph.!jrc~ a n d I'nrpnndnZw show evidence indici~tingt1i:~t thcy arc not pelagic* 1)1rttotic1 to live 011 or close t o the seu-fioor as adtrlts. s, and Lucijer are Generally, rnetnbcrs of' t , h ~gencri~r l c ~ t ~ Peisos pelagic ~hritnpsititlsbiting inshore or neritic waters. Some occur even in arcas of st~lirlityless than 20%, and are frequently common in estuaries and bacliwaters. Occ.asiondly, a few species of the genera E'unchlin, Sergestes, Sergia and Pasiphaen also occur on shelf water. Offshore or oceanic inhabitants are represented by the genera Bentheogennema, Qennodas, Sergestes, Sergia, Yetalidium, Oplophorus, Acanthephym, Hgrnenodorn, &stellaspis and Parapandalwr. There is an isolated group of pelagic decapod crustaceans in the furrlily Gnlatheidae (Anomura), although they are not true shrimp. It is well known that post-larvae and adolescents (Grimothea stage) of Jlunida gregnrin (F~~brici~is), Plruron,codeswtonodon (H. Milrie Edwards) ancl P. plnnipes Stimpson appear in v a ~ swarms t respectively in the surfiirc wstcrs off New Zet~lantl--Stlbarctic islands-Patagonia, PeruChile imd in the (: ulf of (!i~lifor~lir~. 'rhe systcsm:itPic.s and taxononly of pelagic shrimps have made tnucll progress in nunirrons contributions published since the various occanogrz~phicrc~set~rch expeditions by European countries and the [Jnitcd Str~tesduring the period from lr~tenineteenth to mid-twentieth centuries. However, the species within the genera have not been tIio~.oughlydesc.rihed yet. Thcrr*is still somcl confusion in t,hc taxonomy, and t h c 1111tnbc.1. of species ix not known in many genera. Turning to tho litc~rat~ure, I)SL~J(TSby R~LI'I~~LI'(~ ( l !)SO), Burkc:1irot~(1 (1 936, I 1137, 19401, Mnnse~i( I 019, 1922), Kr~ril)(I!) 17), Kensky (1971 ), Pathanxali (1966), P{*tit(1!)73) Sr~nd(1920) rind Ytcltlwyn ( I 957) are important contributions to t t ~ etrrxonomy of penaeids (family Penaeidae) and sergestids ( f i rnilg 8ergcstitl;te); those by Ralss (1926), Chace (1936, 1940, 1947), Holthius (1!)55), Kemp (1939), Sivertsen and Holthiuu (1956), Smith (1 884). Sttyhcnscn ( 1 923) ilnci Suntl (1 9 12) ;Ire csscntial for the identific;~ tion of t hc ca rids (section Ctlridea). Regcirdiny the ~ysternaticsof the genus Sery~,qtess. 1.. Yaldwyn ( 1957) drfined two subgenera, nitnicly Sergestes s. s. A. Ililne Edwards, 1830, nntl Sr~r!jin Stimpson. 1660. AH desc~ribecllater, the morphological diili~rt~t~c.cn between the two sul)gencm are cons~~icuous not only in tlw str~icturrof luniinc~scc~nee organH but also in the type of early devclopnlc*nt+tlstages. I am thorefore of the opinion that these

2'36

M A K O T O OMORI

'I'AI,I,EI. M A . J O( :IE~N I C I C AA N I ) I{KPI~KSI~:N'IATIVF::SI:NATIVE SPECIES OF PELACIC SIIRIMPS (Nulllbcrx i l l pnnv~tl~osc~x arc1 r~pproxi~ntttct number of specie^ in the genus)

fi1111i1yI'filNA hi1 l)AlC uul>fiunilyAII IS'I'EI NAH ~ O I I I I SHEN'l'tfEO(:KN1\'EAIA

(4) bornalix, intern~erlium,pa,oitheu, stephenri gc-IIIIH O E N N . 4 /).45 ( 1 5 ) bor~niari,cloqulu?~~, infeltus, parvtrs, propinquus, sc?rtattts, tinnyrri, vale118 sr~l~ft~~rlily PKNAKINAE: g ( b rk'(7NCH.4 ~ ~ ~ IAIA (8) balhone, villosa, wootlwardi

arcticu.~,amatus, atlaniicwr, corniculum, eclzuardei, erectus, hanseni, sargassi, sirnilis, vigilm grmlls SEIiBZA* (27) challenyeri, gardineri, japmious, lucena, pohna, prehen,.&lk, robzcstwr, scintillana, splendens, talkmani gclula I'ETALI DITTI11 (3) foIincetc?~,obe,vu?v~, eu8pirioszcm g('l11IH ACI{?%=,V ( 1 2)

nnberiratt tin. cliinerr8is,erythraeus, indirus,jqvonicue, xerrlrlalttx, nibogne, urrlgurix gt-nux l J h ' I S f S ( I ) petrtrnkev.ic.11i

chacei. fa.cotbi, hanseni, intermedizccl, orientulk, penicillifer, t!jl~rra u ~ ~ ~ ) c ~ r h Z'ASIPtIAEOlDA ~mily f 1 1 1 1 1 i l y PASIPHA EI1)A

li:

ytvuls PAS1 I'HdlCA (35)

acutgrovzs, alcocki, chucei, hoplocerca, liocerca, long.ispina, multidentata, pacijca, rathhunae, semi.~pinosa,sivado, tarda gcr~usPARA PASIPHA E (7) compla, cristata, serruta, sulcatijron*~

* New separation at the generic level.

TIfE HfOT,C)OY OF PEI.A(41(! SHRlMPS TN T1IE OCEAN

237

olb(lorUE:(ltZl'OI)A

sr~l)ortic.rMACHURA rr~~pt.rnoc-t,io~~ NA'I'AN'I'IA

gflllUR OP1,O)'HORtlrV ( A ) gvacilirostria, novaezeelandiae, apinicattcla, ajhocnts, tY1)'M gonus ACAN THEI'H Y H A (27) acanthitelxonk, acccfiijvona,curtirostrk, erimia, indica, pelrsgica, yurpureu, qudri~pinoea,aanguinea, sexapinosa, atyloroatratk genus MENINWOUURA (3) mollia, aibogae, vesca gonits NOTOSTOMUS ( 1 1 ) distirua, elegana, gibbosua, japonicua, lonyiroatria, mumayi, perlatus, ~obuatua,meatevgreni gc31111s EI'H Y R Z N A (3) benerlitti, hifitla, hoxkynii ~ O I I I IH H YMENO1)ORA ( 4 ) nearcthitelsttnicr,frontalis, glncialir. yrci1i.v ~ I ~ I I I ISL;S1'EIIIIANl'lA' H (5) n8ni.v. hrattrri, cviutatn. clc,l~ilin,lanceocaurlata supc.t.fnrnily PANDALOIIIA fn~rlily1'ANUA LIDAN gc*n~rs1'A RA I'A N / ) A LIJS ( 1 3 ) richarrli, xpinipcn, zttr.utm.v.~rrri fittllily PHYSE'I'OCAIII 1 ) I T ) A E genus I'H I*NETO(~AIIIS( I ) t~vicro~ththalnba

differences are worth more than subgeneric recognition, and in this prcper I have divided the genus Seryestes s. I . into two distinct genera, Sergestes ttnd S'urqin. Many areas of the world's oceans have been inadequately sampled r ~ ~ i the r l gcnerul geopra~)hic.r~I clistrihr~tiollof only tl few species ix well

238

M A K ~ T OOMORI

known. 'l'huw it is inlpractic.al t,o attempt in this paper to define the geograpl~iatlliniitti of t ~ n yone nl~ecirs. Records of the occurrence of apeeicts ill t Iir l i t c r t ~ t l illdi(vitr i~~ that lj!lmJ~nodoru glacialis (Ruchholz) exte~icis i t s (li~tril)iit~io~l to thr arc:ti(: rc8gion (Stephensen, 1935). f'u.vip/~ctoet m~t~lti(lontn/(~ I3snittrk i~11(1 1'. turd41 Krwyer itre found along ~ iis 7O"N, iiritl u few rriore spcoies sttch the No~.wegii~~i fjoi.cls iix f i 11orth as Ser!jc?stes nrctir.ti.u K rcjycbr.A'. a.in,ili.9 H~LIIWII, IIyrn~nodorafronlalie Rt~thbtinurc foit~~tl ill the s ~ ~ l ) i ~ writers. r ~ t ~ i ( ~In the Southern Hernisphere I'rtctlidiz~m,foliacc.um Biite i~tldtlymrnodom gracilis Smith occur off' Endcrbx J l r ~ n ~( Halt%, l I94 1). However, i ~ p a r tfrom Pnsiphaea l o ~ q i ~ p i nT,cnz a i ~ n dStrunck which wiis recorded from the Rovcr Sea (Borraduile, 1918), none of the species hus so f t ~ rbeen recorded from the tmtnrctic: region. Thus most of j~elagicshrimps are found in the tcn~pcrr~tc.,siihtropical and tropicti1 regions of both hemispheres, ~ t,hcb f t ~ ~ i ndiversity i~l from the subarctic regions Appiiwnt i l l ~ l ' 0 i i N in to the tropic:itl regions hiiis h e n rcporteci in the North Atlantic and the North Pacific: Ocei~ns. Iqoxton (1072b) stated that the number of ~teltigichsl~rimljspecies rccordecl in tlie upper 2 000 m at 803N, 53ON, 40°N, 2H0N,I X0N imd I I "N iri the eastern Atlantic was 15, 12, 29, 27, 5 1 i~iici43 i*~nprct~ively. 0rc~;iiiic..I~M'cI' rntwo- u11(1 buttlypelagio* shrimps such as h'ereryia ,j(tpo)ti(:t~ ( Hate), Oplophor'us .vpiv~icaudaA. Milne Edwards, Acnntheph!jrn c.urtivo,strz',s \Vootl- M itsotl, A . tt~ie.t.ophthnlnuzSmith, Hyn~enodora ~lafiicrliu,S,y,vlelkc<9piscristata (li'nxoti), S . dchilis A. h 1 i 1 J3dwards i~iid An,phion.idex re?ynnudii ( H . Milne Ec1wurds)t havcb very wide geogrciphio di~t,ril)i~tjoi~s t~nd11itvr be011colle(:ted sporadically from the Atl:tntic, Tndii~nrind Pacific* Oc*cuns. In csontrctst, rpi- and uppcr ~nesopc*lngic.sl)rcic*xinc~lutlir~g nitirly ncritic forrns are more ofton than to o ~ ocScan, ~ c or cbvcnto olitLpitrticillar urea of water off not rc~st~rictcti u siiigl(>cboc~stof on(*ocvun. k'or rxurnl~le,Sergia lucens (Hanuen) has Bay imd its i~tljacent waters off so ftw bcc.11 forrnct only in Sti~~ugii . J ~ L ~; ~A4~:~lr,.9 L I I chin('rl8i.v H~ttsetiis extrttorc1inarily itht~ilrlt~rit only

* Thv tornis " t'[)itmlagic ", " ~n('st~f)crl~gic " und " hat h y ~ ~ ! I u ~ '' i~cU V Cbeen (fefirti!il by Flt~tiglw~1.h (1967) nnci ~)thor.n in t11~pant. Irl the prc.xent paper c.pif~r:lagicid 0 to 150 rn depth t)y tiny. 111~1~".~ne~op'lngic is I5lJ t,o 500 rn, 1olr.c.r mr.*opolngir i i 501) t i ) 1 000 rn, lrricl bntl~ypclt~gic? in 1 000 t,o 4 000 n ~ .

t In

tliacl~rr~i~~ci with I)r .'L

Hot!gaartl rt~gnrcling tilt. s.ysteniatic position of

A~~rphio~riticn. wcx axmr~tlthat thin cnrliiot I J rcxteinc.tl ~ in the (laridoa, whrtrc most recent

nt~t~horn Iisvtq ~ l ~ cit,, t and ~ l t.hwt t,hu An~l>hio~~itlidc~n shoulrl bc! rc!cognizerl as a section of tht3 1)cwapotlu. U'illia~nnon (1974) tlincunut~xthis rnntttv wit,h rich material from tho -4t,lontir n.nti IntIi~11OCO~IIH. He I J P O V ~ ~ R Hv a r i o t ~~ C U R O I I S ugainut t,he inc111~ivri~f A ~ ~ c p h , i o ~ tin i d rthe ~ Cnridea and ~uggtwtnthat tB\.cliitx mt.crlition in the 1)crcapode m ~ i s t i)e mrio~~uly r(~c?t~~lni~I~~~~~~~t.

floor, probably clout?ly rissociatd with loose detritus on a muddy bottoni, and their occurrt~iiccin tlic pcliigic community is rather scarce. Aeuntheph!/rn exirnin Smith. body length up to 180 mm, for example, is collec!ted not, oii1.v by t h c b bottom trawls but, also by the traps Rct on the Imttorn (Clarkc, 1 !)72). In I)ehigic shrimps thv iiitegiimciit is not, rigid duc to poor ctilcnrrous coiitcnt, particulerly in thcl batlrylwlt~gicspecies. Pereiopds and ploopods arc grnorully well rulupt,tvI for swimming. Several adaptations to pelqic or planktonio existmcc can be seen in the enormously developed spines and processes on the carapace of protozoeal and zoeal larvae of the gciiera Ser!/estes and Rergio and the heavily setoee antcnnule and antonnu of larval stages of fJennadm (see Figs. 13 and 1L). In t h e genera (Irennadaa, Furwhctlia, Sergestes, Bergia, Acetes and Peisos antcniial flr~gellaof post-larviw rind adults are not,only extremely long but are: flirther characterized by being divided into proximal and distal sections ; the difit~alsection being heavily setose. These structures no doubt serve to increase the surface area without, an undue incream of the volirine or weight. and in this wciy help to retard sinking. Also, the storage of oil globules or large amounts of lipid in the larvae of such carids as the genera Pa&p?men, Parapnsiphae, Oplophorua, SystellaapiS and Hymenodoom reduces the fipecific gravity. Pereiopodal exopoda are developed in all genera of the Pasiphaeidae and Oplophoridae. Thompson ( I 986) noted that there is a constant reduction in the size of the exopod of tho pereiopods from pelagic to benthic species within the member8 of the gcniis Acnntheph?yra. Pelagic carids generally bear tttt mandibles cttpablc of both crushing (molar process) and cutting (incisor process) ('l'hompson. 1966). Sergestre, Acetee, Lucifer and some speciw of h'ergirr which live in the epipelagic tind upper mesopelrrgic zones are tranRparent or Hemitmmsparent, with few l t q c orange or red rhromatophorea and largely colorirless chitin (half-red shrimps), hut ull shrimps inhabiting water below 500-700 m depth by day htive numerous vmall chromatophores and heavily pigmeiitcrl chitin that varieH from deep-red to scarlet (all-red shrimps). I'hotophores or modified gastrohepatic gland tubiiles. which have eithcr betan suspected or have been shown to be luminous, are observcd in mimy species of the genera such a.8 (?ennadas, Serpvfee, Smgin, l l p r n o d o r n and Parapandalus. Acnnthephyrn is known to produco n luminous secretion. Oplophorus and Syy~tellaspis posscss hot)h dermal photophores and are capable o€ luminous secretion. The structure of luminescence organs of various species has bee11examined bp Kemp (1910a) and Dennell (1940).

ILL 13tonzass

As seen in S~qoslas.uindis, Sergin lucms, refee sppp. and Peisos pctriurkevifr*hi.somr epip~ltigici i l d upper meNopelegic shrimps occur in v a d swttrnis in rest!rictcd waters. Thus thcir distribution is usually uneven both vertically aiid horizontally. ('hpability of certain micronektonic animals to avoid nets by visiial perception during daytime is pronounced at shallow depths, 118 confirmed by Pearcy and Laura (1966) and 13rinton ( 1 967). I havc often found that the biomass and species composition of snmples varied wit11 the sampling time and position, PVOH if thc! Ramp gear and sampling technique were used. In certain waters t,Iw most ctbtindant spwics changed in each sampling. These phcnomeritt suggest that ( 1 ) tho mobility of the shrimps varies considerably among the species, (3) the shrimps are often patchily distributed and (3) the position, zone and density of the swarms are changing incessantly. UnlesR the distributional and biological features of the individual species are known, an accurate estimate of the true abundance of the shrimps is difficult. Tho real density of Sergestes siinilis and Sergia Zuccns in the swarms is believed to be more than 20 inds./mg, but estimation by net haul has never exceeded 3 inds./m3 (Omori et al., 1972). Thus our sampling only gives an average underestimated density of the shrimp in the fairly large amount of water where the net, was t o w d Natirrully, the biomass data determined with such surnpliiqp iiro qiiite insrrficicntsto evnluntt. the role of each species in the seit. Table IT sliow.~the itpproxit n d o biomtiss (dry weight) of pelagic shrimps nbove 1 000 ni depth in various parts of the oceans. These values w c w drrivetl by re-eulculation of the data from available referenccs, but nny errors or wrong interpretations are mine. The re-calaulatione have been rnadc by rising the foliowing convertion factor ol)taincvl with several Npeciea of the genera Sergeste~,Sergia and Acnnthephgm: 1 g dry weight = 9.2 g wet weight = 6.7 ml displacement volnme (Omori, unpublished). The depth of' bhe maximum concentration of the shrimp biomass, as noted in Section IV, vctrics according to the locality, but a8 far tts the water column shallower than 1000 m is concerned, the geographical vciriation of the average biomass in a wide area i s not very great. The biomass is large in inshore waters and localities over the continental slope. ' It decreases with increasing distance from the coast. Thc concentfration of shrimps is particularly great in water where the bottom slopes steeply away close to shore. Usually, the

242

MAKOTO OMORI

0-0

180 78 16

Bhckburn, 1968; Hlackburn et a!,, I970

0-210 0-210

164 (17

Legand, 1969

100-200

316 209 543 388

Le Gall and

0 90 0-90

200-300 100-200 200-300

L'Herroux, 1971

frequent upwelling of deep wnfor can be expected to shift the isotherms iipwnrd in eitch regions, and the result i R to bring meso- and bathypelagic ~hrimpsso clow to thc aurfaoc that they are able to feed on the muss of xoopltmkton maintained by the highly productive waters. In this oonnection, it h a bcan pointed out that the pelagic fauna of the Gulf of Guinea is very rich both in species rtnd in number of individuals, beoltuw of tho strong upwelling found dong the eastern side of the &tlf (Voss, 1!)6(5). L e p i d (IH6O) determined the latitudinal varicltjionin size of shrimps in the Iiidian Ocean htivecn 9 ' 8 and 32'8 along llOOE, Although ids were larger in he did not mention spooios composition, t h the south, whcreas the sorgestitl~rind caride The proportion of pelagic ehrimp together macroplankton ltitd micronektoii community 32.8% at W'3O'S t o 9.3% ttt, 32% The seasonal vuricttioii of the nlirimp biommrcs is not clear. According to Blaclkburn el al. ( 1070) tho seusonal variation of the standing stook of crustmean micronekton including euphausiids and decapods ww considerable at the Equator in the eastern Pacific, and the maximum/ minimuin ratio was 14.8. The maximum and minimum occurred respectively in June-July and December-January, as for chlorophyll a

and diiy zoopliiiikton. lint the seusonid cyrle was not significant betwecvi I5"N and 3"N. 0 1 1 the other hibnd, in the western South Indian Orrrtn nlotig I 10°K t,lic cwrstawt~iiii~icroti~kt~on, tigain including large niimbtw of riiphtm4itix, ili(;rviLsth(l in May -Anpist, iii the waters twtwcon !)"S and I S":lO'S, with tlw niiiiiniii owwring betweeti t)txembcr ltiitl I ( ' e b r ~ i ~(I,c~gand, y i WN). Our (liit~itin Sagami Hay anti idjaoeiit waitmd indicatnc that tho shrinip h m a s s is more stable throughout the y~atrtJim other zoopltinkton. The variation is not statistically dixtinguishthle t ~ as seasonal cy:yc.lo. 'l'hix stability might be due to these animids having (bither gencmlly 1ong:c~lifk cycles or slower responses to environmcntid changes drie to thcir higher trophic level. Awordiiig to Aietiwa ( I S M ) , tho ))roportion of pelagic shrimps in the totlad zooplttiikton and microtic~ktonbiomass in the upper 1 000-m strittnrn off thr Pticific coast of Juprin was comparatively stable, being 3 to J3'%,. r i i Sagami S a y the shrimps comprise 12% of the total biomass (Aizawa arid Marumo, 1967). Th3 rok of shrimps in thc pliinkt,on community is not great in sub-polar regions and it increases with increasing species diversity in sribtropiral and tropical regions. I n samples with the ORI-100 net, 180 ~ r in n diimetcr Itrid 1.0 mm i n mesh openings, the proportion of the shrimp biomaw to the zooplankton and inicroiiekton in the upper I 000-m stxatum at night s t 44"N, :%7":IO'N, 30"N, SOON, l0"N and 0" i h i g 150"E in the western l'iloifi(* in 1)tvember wits 3 2 % , 6-3%,, I I -6%, (0 500-111 stratum), 1 6 * 7 ~ 18.7% 3 (0-500-m stratum) and L5-2%,, rc:dpec.tivelv. These tltitu sugg(viC that shrimps generally comprise about, lOo(, of the totid hioiniiss at, 0-1 000 m in temperate and tropicttl regions (Fig. I). A t ci>(*llsampling station the shrimps, euphuusiids and fish cqonstituted t he main part of the micronekton and tlioqe tlnirnds together made up 24 to 72';4, with an average of .56:/0 of the whole biomltss. k:uphau~iidswere usuully abundant in the shdlow layera, whereas shrimps arid fish formed the greatest portion of tltic> bioiniiss in the doep layers. A t it rough estimate the shrimps form 1 Ti- 25g; o f t he microrirkton arid itre comparable to the euphausiids (3s-500;,) ~ t i dthe fish (20-450(,).

1 v.

\I #HTI('AL ~)IS'I'RIB~JTIONA N D JtELATED ~'RORLEMS

A . &?wral wrtical distribution Peliigi(: xliritnps iiro clistributrd ut various depths ranging from the wrfaer t o iit Iwst 1 OOO-fi 000 m. Up to now, t,hfirvertic:al distribution has mostly hceri xtudicd with nets or trtbwls without dosing mechani~mrr. Sampling h-y the oi)cning-closing net has wsrcdy becn oond uc:krl in the

,'I .R 3'8.G 71.: I).1

8.6

7.5

i.0

9.3 4.5 4.1

2.7 1.0

1.0 1.7

2.3

chyths greiitJcrt l i i t i i 700 800 111. (Jeiicrally, the nets and trawls can be towed lroriaoiitdl,y i i i a stcible c:otitlitioii uhove 400-500 m, but below thow clel)tJin, I)c~uuneot’ currwit ecluipmcnt, problems, they often waador vc*rtic.nll,vover a rltiigc of 100-200 m. In addition, the number of shrimps pvr t i & haul in off en smctll. I n many cases the lower litnits of pelagic. shrimps am not, defined. The vertkd distribution of’ shrimps, us well us that of other rrustaceitii mrtc.roplankton in general, i R principally modified by food supply, light pwwtxatioii and tanpcrature, although other physical VtwiaLblCs such iLs salinit~v,dissol ved oxygen and hydrostatic pressure must8also t)c? involved. I’rcsnmal)l,y, sotne of these variables interact, ats part of ti complex of mvironnieuttd factors. Generally, tho shrimps occur at dcpths where the food supply is grtutest. ‘I‘hcir tlistribution is con(-entrated in the depths where more food (copepodstLnd other mesoplankton) descending from upper layers is available. Therefore they form comparatively thin layers in shdlower depths in poorly productive areas, whereas they occur in a much thicker layer in the productive areas. According to Vinogradov ( I ! W ) , in the subarctic: region of thc north-western Pacific where it is highly protlucti ve, the shrimp biornuss gradually increased below 500 r n , rewhing its rntLximum in 1 000 3 0c)O m depths. Its proportion in the totit1 pltmkt,gn biornns8 iiicrcwed with increasing depth. and W M highcnt i t i tlic 2 000-4 000 m depth. The shrimps practically dis~ppeni~etl below 6 000 i n , i~lthoughisolated specimens of Hynumodorn gluci(iZi.9 sotnc~tiinc~n ocwirred itt, greatc.r depths. The dominant species varied tlistitic.tly with iricrc~idngdeptJi. Only Swgesks sirnilis and 1ibrvtLc of’ littorid tlccupods wcre found above 200 m. In the 200-800 m depth the c.oiic*eirtrittioii of Henthtwp~anama(as Gennadas) borealis was ltwge, whereas in the 760 - 1 500 m irl!/rnrnodora frontulis was the most ubiuidtiiit np(*iw. Then. N. ylarinlis plttyed the greateRt, role in plankton in thc 2 000 4 000 in depth (Fig. 2). The ahrirnps were found oiily nbovc I 000 i n i i i the urcas betwccn 30”N and 10”N. In thiH poorly produc.tivcb t r o p i c d r(*gioii t h i r gr(’iLt(’Htcoiicentration W ~ found H in the 20& 500 rn tlqjths, tnhtit in, initnc4int,c!ly iuljucont to t h e ~irotlur:tivc* zoti(’. 1 1 1 thc i)i’o(luc.tivc(v{utLtoritd rcgion, the role of H h r i m p was cwpwislly p r w t iri thc 1 000 2 000 t n a m 1 aomewhat smaller in thc 600 1 000 ni t l c p t t i . Below 2 000 m the proportion of shrimp tiomas8 in t h e t o t d plunktori went down to zero (Table 111). As shown in Fig. 1 , our suniplrs showed similar trends although the proportion of nhi-imp in the total biomass a t euch depth was usually greater than t hitt of Viiiogrttclov due to the different sampling method. The shrimps were ciistritwted t i l t to 1 ,500 m depth at W N . 4

w

H -12

0

246

MAKO'PO O M ~ H I

111 t Ire. c.i~rlic*rH I I I . V ~ ~ Y i l i t,l~(bNorth Atli~llti~, Murray ailcl H jort (1!118) 11otc.tl 1 l l i ~ ti t ) i~l)outG O O N i~ll-~'(h(l ~lwi~rlps had ;MI upper litnit a t 500 111 e ~ o r t ~ ~ to ~ ~ii~limit r ~ c dof 200 300 nl (lot>p(~r ill iibo~t, 30''N. s111)s c ~ c ~ ~ly. u ~\ i\rio~l,u r ~ l irl\rck~tigiltiotln r*c*venlrdtlirit t01c vcrticvil ciisl ril)utior~

1 I100 -

?11110

-

Bent hrogennema

-

1000

-

4000

-

t

I C111

n

6000-

7000-

2. \ i ~ r . ( ~ r t~t l l u t r ~ l ~ t r t iooft ttllv ))lornctw~of tlc~capotbrn tho rrglon of tho Kunlr.1S1~t11c-h~st ka 'I'riwrll (ILVI-I'H~(+ 11, I I ~ I I I --tat 10114). 'I'ho 111~1nin&nt RPPCIPH HPP intlloatotl ( c . ~ * t l l . ~ ~ \ ~r lIi ~ I I Vn~oyruilov, II IHtiH).

of Oplopi~or~cs .~pill0511~ (Hruclle), Acanthephyra pelagica, d l . purpurca I L I I ( ~S!/~t~Ilmpis d(:Lilisin t,hc cle&rand warm water of the Sargctsso Soa i~ (l(~(q)c~r than that in the other waters. The effect of' light ir1tt:nsity is laor.(. c.li~iirlytlofiried in the distributiorlal behaviour of Sergia lucen,.s wlliclh tlo 11ot nligrate towards the surface a t night when there is a full rllootr (0rnol.i. I H(i9rt).

0 50 50 1 0 0

I00 300 PO0 A 0 0 500 1 000

I 000 2 000 2 000 4 000 4 000 -6 000 > 0 000

On the other hand, Sergestes sirnilis occurs near the surface a t night between 60"N and 42'N in the mid-North Pacific, but it is restricted to below 270 ni in Sagami Bay (35"N)where warm Kuroshio water occupies t h s upper layers. At all localities the temperatures at the d c p t h of orcnrrenee were between 3" and 13"C, and the peak iLblitidanc(*of t l l i t b x p w i w tit, night ocwirrctl a t i t bout, the depth of the fi 10°C i w t hcriiis i t 1 siitittncr (Oiriori o/ nl., 1972) Similarly, four species of' tht. g~iriisrlc'rti,fh,qd~gmin ttw eustmw North Atlantic between 6O"N iLlld I I "N ocwri*ctl i n depth ri\ngw that wen' associattd with geogr;~phic*iiI gridicwts of tcinperrtt i i r ~iir t h mcqxlagic zone (Foxton, 1 972b). Hpnl)iaogcrLncJrnrc~horcdix is iL typicul batjhypelagio species living mostly b c h v 700 m i n ttliv twnpcratc. North Yac4fic, but it owurs abrriiduiitly iri thc. incvwpdrb#ic*%oii(' i t 1 Hubarctic! rc!gionR. Figiirv 3 stiowx the vcarticvrl rnigrstioa of 8eryic.i lurrm tog(1thc.r with profiles of t,c~inpcriitiirc~ a t i d Hdiriitg i ~ h v e 300 III in Srrriiga Bay. k'rotn the (ttttii p r w c n t d here. it car1 he wen that the dopw of isohdint: iLnd isothern~al surfaces are g c n r d l y parallel and that vausativr, rchtionships ~ L I V difficult to ~ ~ S S C H S .However, the species appeared t(J be uneble to pnsx the salinity gradient of 0.4%,, or more over a 10-m depth intcwul. l h s e (1964) noted, in this connection, that attention xhoulcl bc. piid to stratification, particularly of salinity, with regard to tliv verticid inovtlment of zooplankton. Other observations showed thtit the shrini 1) populatioii decreased where low oxygen values prevailed within tlie upper I 000-m of the western North Pacific (Aizawa. 1!)6X). 'L'hix sngpcxta that certain fipecies ucrc restricted to the water layera abovtb that depth.

Amplitc~deof the vt.rtrc~Idrstrrhutiorl of Sergia 11icens and profiles of temperature ancl saltnrty in Suruga Bay. Sumbcr in lui1vt1thosr~r monrlr the IF of the rnch)ll.

1J1ar. :1.

rl'(~liitlclo~~ovi~ ( I !#A!)) i ~ ~ v rig.~to(l st t l i ~w r t i(.itI distri1)11tion of' lkw 1wl;tgic sh~.in~ps i n t,h(. 1101.tIl\rrc~stc~1-11 I'r~c.ific., ilntl found that t,hc sp~(*icw trnclrd to occur at different f ) o p ~ ~lo11 l i ~ItI I ~ L X ~ Io~fNc.o~lgchrrc.rictlapths. I+"oxt,ol~ ( I 97 111) sl1o\v(~Ii\ siniii:~~' phcno~n(~non in the vertical tlistrih~~t io~rof 1 pq)c~c%ic.s i l l t lrc. gc3nchn~ (;~trrr,r~~los. Set-!j~strs, IV~ryiutind ~\'!/sIellrc,spix off t I I (~ ' i ~ n ~ ~1sl1111tls rg tlr~~*ing t thc diiy He suggested that into the ~ 1 ~ m118t a he of primr soli~r~'il(liittiOll~ L I Iits~ ~i(~n(~tl'i~tioll itn1)ol.t;tnc.c i n 1~~4i~tiotl to si1(,11j)~tticr~is of' v c ~ical t ciistribution. Prei t l suggestetl ~ ~ that the 1i111il1it1-y di~tjitof' 1ni11t'(O~nori.~~ll])~~t)lish(vl) g c x ~ ~Ser!fin l ~ s i n S u r ~ r g Ili~y ; ~ sliowt*tiit pritcl~~itl progrt~ssion; by day the ~)rinc-il)i~I pitrt of' t#l~tt~ ) o ~ ) ~ ~ l : ot tfi' o9 .nl ? i r ~ n oc.c.nrred s in 11 stratlrm of 200 111 ; S pr~hpn.silix 500 700 rn : S. jnponicus I 000- I 200 m phnnomenol~ itppcbars to be ~.tbspc~c.tivrly.Ilowrvcr. this i~ltcrcst~ing r ~ l a t e dnot o111j~ to t h cwvironrnental ~ light birt also to temperature itrlct foot1 cwnlpctit ion, lind any interpret,et,ion remains ron jectnral ~rnt~il furt,hc.r d(btaile(1s t > ~ ~ darta i e s mtulr. 'I'hc~ xl)(b(aies c-livcrsity of citrids sttnirled the meximum between .jOO itrltl 2 000 rn tlepth in t h r t,ropicaI regions of the lndian and Pacific 0ce:tns (Vinogradov, 1968). Near the ('Ianary l~litndsthe t>otalnumber of s1)ecit.s of all pelagic shrimps illorrased with depth and \vits greatest s t 925 m by day, but tho number oc-curring st shallow depths increased i1t night duca to migration and no oviderlc.e of' a grailient with depth 100 atid fIO0 111 (1tyt 11 (Foxton. 19700). wiis f o ~ l ~lwt ~ c \V(Y-II l h c b

cii~trt~sl \(brti(+;~l ~nigr;ttions ( ~ r n sto ocrur i\'itt~ 11 f'(l\v c*s(vptio~~s i n all c y i - ;inti rnosol~t~l~tgic. sl~r-irnl)s.t i l t l~or~gll thc 1)ehnviolrr of an il~(iivi(l~ll~I sl)e(*i(wIIRX not so fiir 1)(~(11i stl~ditvlill sitvh dt>tail ILS that dcsrri1)c~tlthr cbupha~~siids by I3t,int011 (l!)fi7). Figure 4 shows the vt3rtit:til tlistril)~ltion of c-or~~pitr;ttivc~l,y nI)rrt~dantshrimpx obsc.rvctl ~nitirilyin tt*lnl)c~rate; ~ n d~ubtropicalregions. Except for the case of ft~c~cling rnigritt,ion. vcr.ti(>i~l migrants (lo not remitin in cc!rtain dopths ilt tt~lyhol~rbut move illvt?ssttl~tlylrpward or downwartl unlt.ss thejr c~llcorrnter tl~cx zone whic.h is physiologically unfbvourat)le for tho npr~cirs. It hues!)(ten observed in vctrious animals that they &pparently begin to n~ovr.upward in the water almost as soon as they reach the lowest point of their downwanl excursion. 'J'herefore, in the strict tctrrn, atnplitudes of the vertical distribution of a species .scn~cof tJl~c~ by d i ~ yitntl I)p rlight m y be continuor~e.hut in this paper the depth.rt4i~rto ttrt. Ic\.c.l at whic~lithe ~)rinc.iprilpart of the species pol)ulation

I I

S P L I

BENIHEOGLNNEMA

B.

GENNADAS G. ti. 6.

.. IlOlltAl. I!,

PARVUS

(1) (1)

VALEN:.

(b)

tLtGAN't

(15) (6)

SERGESTtS S l M l t I S

([I)

S, S. S. S.

(10)

S. SlRliIA

S. S.

s, 4.

((1)

INCLRlllS

FUNCttALIA V I L L O S A

S.

(1)

INlERMIDlA

SlMlLlS

PECTINATUS

(11)

(6)

VIGII.AX

(6) (6) ARCT I CIIS (! 5,17) I U C C N S (8) t ' R E t I E N S I L I S (2,9) SI'LEND~NS ( 6 ) ROBUS'IIJ$ ( 6 ) JAF'ON iciis (6,131 SAHGASSI

CORNICULUM

ACETES AMERICANUS (16) LUCIFER r A X O N l (16) PASIPHAEA SIVADO ( I 2) ?* P A C i F l C A (4,111 PARAPASIf'IiAE SULCATIFRONS

P,

SULCAllFRONS

(15) (3)

OPLOWORUS SPINOSUS ( 5 ) 0. SPINOSUS (3) ACANTHEPHYRA PUADR ISPINOSA (1) A. SEXSPINOSA (7) A, PURPURtA (5,7) A. PUHPUREA ( 3 ) A. A C A N I ti1 TELSON I S ( 7 ) A. P E L A G I C A (7) A. PELAGICA (3, A. PAIONOTA (7) flENlNGODOKA VESt'A

(r))

HVMENODORAF R O N T A L I S (13) H. G L A C I A L I S (14)

(5) S. D E H I L I S (3) PAHAPANDALUSR I C H A R D I ( 5 ) SYSTELLASFIS D E i l I L I S

PMVSETOCARIS

MICROPHTHALMA

(1)

I .

.....

HHHH

......

blHt

.....

I

..-

I

........ .......... ........

.....

*

*

l

a

r

r

1 *

1

---

l

l

.__ t

1

1

1

"

1

1

1

,

1

1

1

]

ioao ison 2000 2980 FLU.4 . \'tw icrtl tlisf.ribut,ionof pslnKic shrimps. Solid lines mtran tho rango. Uof.t,td i t r i d hntrhotl amas intlicat,o thc rlepths of thc main (lay and riight?concrtntrationx. 'lbfiwnccs I I ~ (, I ) Aizawe, 1908; (2) Aisawa, 1969; (3) (:haat), 1940; ( 4 ) Clarktr, 196fi; ( 6 ) k'oxLcrrt, 1 9 7 0 ~(fi) ; k'wton, 19701): (7) Poxton, 1972h; ( 8 ) Omori, i ' J 6 Y i b ; (9) Omori, iinpublishecl; ( 1 0 ) Omori el 01.. 1972; ( 1 1 ) I'earcy and F'orw, JW;: (14) 8tephnllHm. 1923; (13) Tchindonova. 1959; (14) Vinogrcttlov, 1 9 6 8 ; (15) Waterinan et nl., 1939; (16) Williams, 1988; ( 1 7 ) Y a l d w p , 1957. 0

500

'I-IIE UIOI,O(:Y 01' P K I L A ~ ~ I SCI' I I ~ L M P SIN ' C ~ I E OCEAN

25 1

oc.cbttt-si ~ t1 1 0 0 1 1 ;111(1 t ~ ~ i ( l ~ t ~~.c~sl~c-c.t g l t t ivclly 'l'hcl ibrnl~litrldt. of' vertical 111ig1-t~tioti I - ; L I I ~ ~f'(v~o11t ~ lcbss ~ I I ~ I I00 I I t t t it1 11108t~neriti(*sl)c%ci(w to 600 700 111 c t v IIIIII*I* 111 ~('~1'l'il.l h j ) ( V ' i l ' ~ 01' (~'PILV(&S itt~dS C ~ ~ ~How' I L -. Of' 1l1c~nopl~~ilgi(~ it]ll)t';ll'N to I'illlgC t)~t\\~eCll 100 ~ l l d . cbVelp,tit(. 111i~jol'it~y 400

111.

Lhc- t l i t ~ r ~ ~rrlig~-iet~ion i\l is c*onsid(brt.cito bc inhrrent, and the endog c t c ~ i sr t 1 1 i s t i t I i i . l%rldjakov(1970) stated that the f l

t t i t ~ n ~vc.rt,ic.i~l i~l tttigrl~tio~l is t l l ~r(*st~lt~ of a11 alt(*rnatioxl of phases of r~~ot~ioti. 'l1he rnaximurn velocity of higlt ittlri low :l(*tiviLyof' 111)~ilrd t ~rVcr!/ia t i o ~ ~~ T I P I J ~ Mobsc1rved , hy net clown\vitrtl t~ligri~t,iot~ of iL ~ ) o p ~ ~ l of ~ibll1l)iiltg~ i ~ l i ( 1I)s il(~ho-so~~ncic>r, was ~bboutfi.2 tn/h it1 tho ~ o c a sti~gc.. l I5 rn/h in csa~-l,ypod-lurviil stages and 108 rn/h in aclults, whereas the 41 vcxra~gc sinking velocity of freshly killed individuals under similar t~~~vironn~c.nt,i\l oonditionq was about 6.6 m/h, 16 m/h and 120 m/h r't~sl)~ctivc~ly (O~nori,unpublished). Thc velocity of the descentling ~ ~ q ) t ~ l a rt i, ~i on t~~~be o t deemed the velocit,y of' actual downward movenlc111tof i ~ t inciividual i ,shrimp, 1,ecaust: the ~llrirnpswims intermittently 1111, t1101t down, hut t,hi>ntat ~novernentis t l o w ~ l ~ i ~However, r~t. a simple c*otltpi~risor~ of t l ~ t bsinkil~gv(~loc~it,y of thr freshly killed individuitls of AS.11rrrr~swith the. tit~sc.c~t11 vc.loc*ityofthe ])opulat+ionappears t o support, ~ of' f.?pipc>lagic.and upper Itl~dji~ko\.'s cbo~lsitlerrttio~~. a t k ' i ~ ~i l lt ~ , I I ( CBRO n~c~sopt~litgit. sllrir1)ps hi~ving to x1)('~ifi(' floating ,rde~i(*(~s. that the I K I ~ I I I ~ ; L ~is~ ~i~ttribt~t~c.tl I \ to piissivc~sit~ltil~g duritlg the f)hitsta of low it. is ~ L I ) I ) A I * that ~ I ~ ~ the migrants loc.orr~otol.~~ irc.tivit,y. At tht>sittltt*ti~n(>, I~c~vc, t,hc ('i~l)it('itr~ t,o 21 (vrtain P X ~ ~ * It I ,~ ~ 1'01itr01 their locornotory ac'tivit,,y so tBlli~ttjll(>y(lati agg~'c~gi~t(~ t,o optimurn c~nvironmentalconditions. 'l'lli~ is evide~ltfrom a vitri(%t~l of sourcrs including echos o ~ ~ n t l i fiw r ~ gti)(. dctc*ctionof tltc! uoni(8 s(-t~tf(*ring l a y c r ~wllc.n* in many (*ILNLW t htx sl)(~bd of tllr (It~~(~erldi11g ~)ol)l~litt io11 is ~imilart,o that of the irst~elltlingl~op~llntion. I'revio~~swork i ~ ~ lOdI I ~ ( l i ~ t isttgg(-st ~ tJhi~tg,principally, various spwicbs in t I)(* I I I ) ~ ( T 1 O O O - I ~ I~tritttitrlh4v(liiy III~IYIJC grouped ci(bcording to thchir ~ ( \ ~ ' t i ( ~nigritt~iol~ 'i~l into fivt. ~ I ' O I I ~ H(Fig. ri). rlth(hsta g ~ ~ o u p s ~III-ludc o11ly atlolt~sc.c~r~ts i ~ ~ aclults. id ( 1 ) h1:litl ptrt of' populi~tio11in Itp1)er 1.50 III Iilyc~rbotli night and clay.

Nr1.itic1 i~tldc\~~il~elagic. ,s~)et*irs inc.luding all rtlembers of the genera .-I r.c>tr.s.I ' e i ~ o si ~ ~ 1,r~~Zfor. id (2) $ul.fi~c.c~ - - 100 nl (night) to 150-300 111 ((lay). ITppt'r rncsopelagic sl)ccies : 8or!jcslcn nrcbtic.us, S. si~nilis,S ~ r g i a ltrce~ts.I'rcxiplmir~rt sivndo ( 13 ixso).

I

ic- illr~st.rt~I io~r (11' Lt~c. ( I ~ I I I . I I R I 11rigl~~tio11 1)f j)eIagic strrimpa. Dotted . 6. St.lrc*trl~~t atttl I~trtc:lr~,ll t~~.tws ir~tlict~t.c~ 1 1 1 1 1 tl(*l,tll.; O S ( I r c r trrai~iclny anti night concontratiorta.

(3) I 0 0 300

111

(~~igltt,) t o 500 7 0 0

111

((Ii~y).

I ,OW(T I I I C I . I O ~ ~ ~ I H N~ ~~ )(( ~* ( ' ~ O:S (~annait(zeir~certus, (I. propinquus I < I L ~ ~ I \ ) L I I h't~t~('h(rlin I. t)i11o8u, ,SF~!/(JW/PR nrrtrnlus Kreyer, 8,allanticus H . hl i111c. 16tlwi~rds.S. corairttlu,r~k'r~yc~r. IS. erect us Hurkcnroatl, A\'. ori~1rltc1i.sHsrisel~,8. pcc./it~rr/rsnSullcl, AS. .sargas.ui Ortmsnn. S . triyi1n.r Stitnl)sor~,Sryicr prrhrr~silis,S.s(:intillans (B~~rkcnroc~d), -4cri t ~ / h ~ p h ! / (girtrrlri,~pi~,osa, r(~ . .s~.rspinosa Kern p, Sy~ltelQr~spis drbill,~.Prrnrpat~rlr~ltt,s richnrdi, 1'. zurstras.seni Bitlss.

111 (tiiglit) t o 750 !)5O rn (day). I.o~.c*rti~c~so})c~lttgic. sf)ec.icts(stlSong rnigritllts): (iennrukrs boucirri Kt~titl), (;. pnrous. (:. v~rl(~ns, Sergirr inequalis (Burkenroad). S. !/~trtii~reri ( lit-nip),8. ,sp/rtr~trns (Sund ). Acnttthephyru purpurea.

( 4 ) 'LOO 400

t Iw whole, the vwt i ( d (list ribution of t’eiist-idea is shiilloww that of ( ‘itri(ka, t ~ i i dSergestitlac ttre most intimately associated witsh the i i p p r proclurtivtb zone. ‘I’hc predominant species of tht* f~imily:Ejvrgcstidae belong riiost,ly to the first to third groups; those of t h P(.ililc~idilt~ arc in thc third to fifth groups. The shrinips of thv first, to third group8 and part of the fourth groiip inigritt,Ck to the cliphot ic., productive zone und eat. whereas t,hos(*of t h (\reper groups f k l oii orgariic remains twtl on hoth migrating and noii-rnigrttting itnitrials (kswnditig from the shitllow Iitvers. \.’iriogri~dov( 1961 ) c*onsitlrretl the I)ossil)lc 1uLthways by which organic inatter coiild I)c ti-unsfiwwl fiuoni tlio surface to a b p a l dcpths of 8 000 r n iisiiig inigratory roirtc1.q. ’I‘hr tcntativc* whemc. presented n\)ovr shows tlittt pelitgir shrimps to soinr rxterit produrr spatially s i d i 11 “ Iiddc~rof rnigrntioris * ’ t i t Iwst in t h c s upper 1 000-m stratom. C o i n p r i ~ o i io f the spwies totals for thcs whole collectinn shows that in ptvicrtil l o w r mcsopc*lrtgic sp(~*ies of the third and fourth groups tirv w n i m o n i ~ n dmoHt iLbliiitltlnt in the oceanic watm-s, while tliose of tlic fifth group arr not. This c4fwt, togethcr with the smallness oi’ lnrli of t hP inigrntion of t)athypeIagi(~ popiilatio~i,results in a density iniiiiinuni sotiitwhwe between 350 and 800 m depths at night. diwnfhepAyrn qicndrispinoen is the most abundant speclies in Sagimi I3ii.v. tint1 the total shrimp biomass attains the maximum in 400 600 m dcpth hy day and becomes minimum at the same depth at night. as shown iii Fig. (i (Aizawa. 1969). The biomass transferred lwtween the 0 400-m stratum and 400- 1 000-m stratum was about 011

t Itiui

I I w i g 1 1 0 I . A t the oR4llore stiit,ion the prjncjpd p)1)11lst,io11 wi~si ~ l ~ o ~100 i t ,I ~ clcel)rl* I 1)y d ; ~ ybut the biomass was again ~ ~ ~ i ~ r iI)c*twcv.11 n i u i ~ ~400 i ~ l i t l(i00 111 i ~ ti~ight,.The sparscbshrimp faurin 500 illid 750 111 i ~ 11ight t liils ~ ( \ ( * Iol)servf>d I ill Ha~raiiitl~ \\-i~t,t>rr; I)rt,wcc~~ (,I. I?. Wi~ltc~i~s. I)(THOII~L\ ( * o ~ ~ l i ~ ~ t i r ~ i ( ' ~ i ~I tthe Ii o ~I4hl~i~t0riilI ~). l'i~vifi(*, M i c . l l c b l ;~ncl(:ri~(I~)~rriil ( I !Hi!)) ( ~ ( ~ I I I O 1-111(~1 I ~ S ~ t h i ~ ta dellsitflyminimurn o i s i t I 3 ) o I I t . Apperently, these layers agree L~ ti'orr~the half-red t o illl-red shrimps wit,t~;I clcyt,h of ~ ; L I I I ~ : tl'i~r~~itioii Ity (ILLY H I I C ~fro111 !.lit* Iow(*I' rl1~-sol)i4i~gi(: to bathypelilgic species at,

;

01r H U J I M A - Z A I : I

\Ai;l\M I I i A Y I

( J u l , lllf~O) w i t / 1 1 l 3 )

W1.I

(Apr. 1967) wcirll\t ( g / 1 0 0 0 11\31

ioll off the C:nllary I H ~ ushowc~d I : ~ ~ it night. lqoxt oil's ( 1 !)7Ob) ol)scbrvi~t l i l t l i f t i si t o of' t i i n a Gennu(1us rleyans, G. ~nle,rnt~r~ti .4/-1r)rtheplqrr1ptrry~w~cr wc.rtl mo.rt abundant, arid together orc3rbfio'j,, of the total shrimp catch. The catch in they c+out~.ib~tt~t.tl I I I I I ~ I ~ ) ~t11tt1 * I . l)io~ntrcis incrt~tst~cl 1)c:low 700 rn with it mltxim~lma t 800 m 1)y d i ~rittcl ~ . at :300 400 rn i ~ r~igllt t w1lt.r.c. A. purpurea dominated, b~lt, t I ~ i o t ~ ~itg:~in i ~ s s showctl $1 rninirnttn~ bct ween 500 and 800 m i ~ t riight (Fig. 7). 0c.cusio11ctll~ . soInca H I ) ( ~ . ~ ( - S01' tli(8 gt>rltlra A'erye~le8. ,Sergia allti IJrrxiph(~cvri ~ r - oli)r111t1i l l gut c-olltclr~tsof' fish ttllti shrimps living close t o or 011 t tic. s('i~-11001..Seryl~sles,sirnilis is reported tto he eaten by tll(a l l r b

0

10

100 Night‘ (2100)

200

0 10 20 30 40 50

\

I

800 1000 -I

L

1000

b’ic:. 7. Vcrt,ical tlist,rit)ut,ior)of pdayic Hhrimp t i f f Canary Tsltmtl. A, tht: variation of

t,ot,ul catch with depth. Day and night totals in numbetw rmr haul (log scale). 13, thtr variation of d~capodt)iom&Yswith depth. Day and night totals in g per two-hour tow, C:. tho vuristion in the numbor of speaies per haul (after Foxton, I970b).

v(hllowtii1 roc.ltfinlr Sdmstos (as S~b(itstodvs), j h k . l u s (Ayres) off IYad1ingt#oti(1’cbreyr:L ct ctl., I Wu). Nwvia Zuwns is ciaten by tlit: gurnnrtl /,c~pidntri!~lrt nic*lnptorr~ (:iitit,hct* i t i SitrlrgiL 1Jt~y(Kosake at al.. 1969). ‘ I ’ l i w ~tl:Lt,iL siiggwi that thry dcsc~~nd to t h c vicinity of thcA sea-floor I)y tliiy i l l piLrticwliLr loculit ies w i t 1 s ( w m ~ s .Pci*c~yra et at?. (1969) suggt‘stttd that tlw prtwditig wrrcwl t raiisportctl iI i r vertical migrating iitiiinnls cluihg the iiight to t h c t’tlgi’ of thr cwiyon where the depth w i n sli~.llowc~r than their iisiitll chytinicb rcBxitlenc-ctlcpth and they thus ! ) t w i t n c l coticrmtretc~tla t or near tht. bottoni \vhrre they might be more avtdiibltl t o thc. predtitory spwirs. Omori ( 1 9fi9a) found that the vtlrticul (listrihittioii of S ’ c y i ~Zitcc>nsis nioct’ intirriutely associated with t 1w bottoni i n withbr tnonths. ‘rhe diurnal migration of the species is intitit- obliquely betwcw the offshore. deep layers and thc inshore, slidlow Isycw (Fig. 8). As tlie speciel;;xcatters widely between 150 and :350 ni by (lay rmrl is often abundant from 3 4 to 10 m above t h e bottom t1t’ilt’ thct stcep cwtitinentiil slope, they can be eaten. even in the other s(!iiHOIIs, by pelagic fish living close to the sea-floor. rt8is siiggcst,ctl that the diiirnal vertical migration of Lucijer fanmi i r t f lie iicritic w u t c w of the northern Gulf of Mexico is being modified t o ac*hicw. litiid~tirdtritnsport by means of tidal currents. The landwiircl t m n s p r t in achicved by the tendency of Lwifer t o swim up iitt’o, or remain r i l ) in, the wcitm column during a footling tide and to drop out of th(3 tvitttbt* cwliiinti (Iiiriiig t i t i chhitig ti& (M‘ootlmansw,

! i ) For I)otl~l i ~ ~ ' \ . i l ( a ant1 i~dultshl~ilnpsin ncritic waters, where a ~ ( L ~~1)1)and flow. this type of the migratitli~li.isc1 i l t ~ t lfib11 ( b i ~ ~i~ ~d(dit~it,c of ~ntbint~aining the animals within tion wo111dI)c iin in~portantnict~~ls their tiort~ii~l habitat. It is wcll kriowli that the species of dcetes occur i t 1 vtbst ~110111s~BIOIIK t8hch('o~LH~. 01) i L flooding tide. ( 1. Ottlo!j~tt,rticnhiflrntiol, (:c*~ic~r-i~lly, t,hc Iiu.vi~c. t111f1 j ~ ~ v ~ t ~ of i l t meso?s and bathypelagic i s i t I H I I ~ ~ I I O U ' ( ' I thi~11 ' ibdllIffi. ' r h ~amplitude of t i t i t i g i i o ~is r l i t growth. Spawning of Stlr!li/r I~rc~r~#x t i l k t w ~)liw('Il('iLr t1hv s ~ l r f ' i ~ a ~t rnight wheli ovigerous ft~tni~l(~s ~LH(~('II(I. 'l'Ii(~ I I L I ' V ~ ~ oI'(hi~rly C stiige~ilrr mainly distributed ahove 50 111 wIi(*r(> tjlllhy (YLII t : t k ~s~lffi(~i(~tit arnol~titsof ~)hytoplanktonand S I I S [ ) P I I ( ~ ~ V~~t ~ i ~ t t ( ' l ' . t~iigl'ibt(~ ( I ~ ( ~ j )i1f2t.r c ~ r entering the zocal stage. l'llc* cll~y(listt.il)~ition of the c~itr1ic.rpo~t-l:tr.vil<. tbxtends to water deeper ~ I I I L I I100 111 (Fig. 9). 'l'lit~ &i(l~ilts s u it11 l)(at~rc~*n 10-50 rn anti 2hO-300 m i i ( O o ! i ! O ) 1'rc.sumibt)ly, S'ergexles. utlanticus, 8. po(.Iittrrtrrx, S. sitttilix, Sr>r!ji(r pr~kettsilisant1 S. sc.intill/~,nsin which o c B c + r ~i ~l l * tlich t.111)hotic.zone at night 1111dcrgoa similar typc: of' iitl~~lts o ~ iogcxttt.t t it. ~tiiyrutiorl t o Srrgic~l ~ ~ t c n ~ . . 'I'he ~)rincail)i~I ~ ~ L I ' V A I] ~ o p ~ ~ l i ~oft i opelagic n carids is hardly seen in t l i ~clul)l~otic.zoric., but usually larvae and adolescents of any given xl)c*c.ics ocnc+urshi~llowerthan tile adults. Juveniles of Nymenodora fro)~tnliaI I to ~ 30 rntn in length predominate a t a depth of 200-500 m, wl~t'ft*iislarge, niostJy rnaturc individuals of 40- 60 mm in length owur t ~ ti~ (l(bpt.llof' 2 000--4 000 r n (Vinogrt~dov,1968). 111 .d~nthephyra purpttr~(rtht* sexes migrate differentially a t night and adult females. espec.ially ovigcroua olies, niigrate to a shallower layer than malea '1'1i(by

,4 si~nilirt.~ ) I I ( ~ I I O I I I ( ~ I I O I I is o f l s ( ~ v ( in ~ 1othe~.spf-citls ( I ~ ' o ~ t o nI!)'iOl)). , SII(,II 21s / ' ~ l ~ ~ ; / ~ / ,~Yf;~I Yf I' ~f l/iin(I O / / , t j t t r ~ ~ t t o ~yrori1i.s / o r ~ ~ (Ktepl~e~nsorl, l+~?:l; S I ~ I I ' V ~ L I ' of I'~l/llidiurtt,sib., ivlli(4l is a ('hir(.(., I!)-10). (irchirt I I I I I I I ~ ) ~ I . ol' t y pic*irl 11it tJly pc4itgic. sc~rgc~sticl, ;I rcb sit rr~pl(btli ~ tJlc t sul.fiiclt ill the subirntrt~.c.tio~vgion((Irrrnc~y.1!)24). zoc~irllt~rvaeof Amphionidcs (as A ~ r r p l ~ i o ra!/trtrrr(iii t~) live- ill thc surfic.c>li~yersdown t o 30-40 m by right, \\ hilst. tllc. i l ( 1 1 ~ l till'th ~ (listribr~t~(l i ~ 2t 000- 5 000 m where the X ~ L ning N t i ~ l < ( *j ) l ~i \ ( ' ( b . 'l'llt* eggs S I ~ W I Y ris(' t,o t Ile surface, during which iot~r~~cby I l i l t chi~lg oc*al~l-s (llc~cgi~;~~-tl, I O(i'3). 'I'itese facts reveal that the I l i ~ t ~ ~ ~01'l ~111irny i l l g (*irrielsiLs well its several lowct. meso- ant1 bathypelayic ~ ~ ~ r ~ i ~irnel c * isc51-gt*stitls tls ti~kespl;toe abovcb their ordinnry udult hnbit:rtioniil tle.l)t t r so t11:~ttj1tt* It~rvi~e c:im rise t~ntloccur in or just below thc: of food. cbl~l)lroticz o l ~ w11c~1.c. t~ tflrc?~.t, is ;I rioh s~rp~)Iy 'ro c.o~lc.l~~tlc thctrc iu.1. three distribut,ional types of larvae on the t~iisisof' tile ontog,rcvwtic>nligrations of the difTerent groups of species. ( I ) 6pcrics rrsually living in the cpipelagic and upper mesopelagic zoncx und Ii~yingtheir eggs in the euphotic zone; the eggs are small, hrtt t,llcbil+ nrtrnbor is 1:irge. Thc 1;~rvaefeed on phytoplrtnkton in t h(hil. ('i~t'li(~l'stilg~siL11d dcvelop there. (2) Sl)c(.icw living in tha 1owt.r mc.so- and bat hygclagic. zones. sptrwning 01. I~irtc~hing i i t the uppt~~,rnost of the v c r t i ~ t ~distributional l ~.ut~ge* 01' : ~ t l ~I~i ~l tn ~ i ~ lt Pt l~l cs~cggs : i ~ l i t lC~LI'IYl i ~ r \ ' imob? ~ lipward ant1 tt~ostof' the. Iitrvi~ldt~vc~lol)lrrc~rrt t:ikt~s~ ) l i i c - rin ~ the c~rlphoticzone or 1i1ye~t+si111 rnc~tlii~tc~ly ;tdjitc.elrt to i t . but t hc juveniles ant1 tidolesccnts 'I'11(1 ('ggs ill'tl litl+g(',1)11t tlltli~'1111111her is few ; some larvae 11rovc~ tlc~.l)e~~-. li.c.11 on I)IIJ l~)l)li~llkto~l. but ot2tlc~rs (lo not fcctl itnd survive. on internal ~ O l kl l l l t i l tll(l)' ('ill1 (Ylt ~ O O ] ~ ~ i l 1 l ~ i ~ O 1 1 . (:{) S~)(~(-i(*s \ ~ I I O S ( ~S ~ ~ I ~ I ~ I II~ I~I ' Iv ~I I ~I alI(1 . ftdllk 1if1: ti if^(^ ill i ti i I rI'l~(~)' air(' IICV('I', ;it i111y~ t i l #of~tlwis life, present I tI ~ i o s ~t l s r ~t r i ~. S(>V(TU~ s p ~ ~ i ill e stlll(l Caritic1a in desrribcd rrlity hcxlong to \vhit*lltllv Iiti.vi~lrititgc*~Iliivc rlot so f i ~ rl~t111 t l ~ i sg~-otrlt. 'I'hcb

I). Sor~ics c / ~ t l ~ r i n !kr!yar.s y III (*(*rti~ill i\tQt'iLS tllc (Iiurniil migration of' shrimps causes a soi~ic. Sergia lucens appears in t,he shallo\rr layers, sc'il t t(vi11.gli~y(>~*. (:e~i(~r~tlly, 10 60 rn. nli~kingt'he grtv~tswnrrns just before sunset and then about orlcb11or1rI)c.fhrc*s~i~rrise it starts to swim don'na-ttrd with the n~ttximurn upit ard sinking sl)c~c~tl of I .% rn/tr~in.'I'lle spcacies begins to move ~OIYI?. i~ytiini n thc wittt~.ill~nostils so011 ns it Iliis rt.i\c.hetl the lowejt poi~lt. 200 :I()() I I I (l(hptl~. of' tl~cbelo\rn\\,a~.tlcxc.~rl.siolr. 7'ht. sl)rcsies iil)pf*iirsto

ittijust its t l t y t 11 cllst rihr~tion to sornc ol)t.irnt~rrls~rhrnilri~lo light rc.girnc. iuld tnigri~t(hsi t 1 rc.sponi:cb t,o vitrit~t~io~~s, tliurl~itlor short t'cnn, ill light irltcr~sit,y. 'l1I~isl ) e ~ I ~ i ~ v;tgrchcn i o ~ ~ wc4I l ~ wit11 the tnovenicbnt of the sonic. V KHz s(.i~t,t,t.t+ir~g li~yc~r*s 1.c.c.ordct1011 thc ~ ~ c - l ~ o - s owith ~ ~ r ~~ ~tCl (~I I'I~C I'I C , 200 ( I . I . Si\~nl)l(.~ r ( ~ v ( ~ it~hl d ~ t,ho t tlist~.il)utionsof t,hrcc groups of' i~trinii~lx wcrtb of'lcrl str't~tifit~(1 i l l or i11'011lld ~citttoringlayers ; from uppt>rt o Iowc~~., Ittrphnusia silteilis Sam, S~rgiaIrtcms and rr~yctoyhid fishcs (Otnori 01 r ~ l . , 1!)73). AltJhorlgh Pig. 1 0 shows no evidence of a " tr~idrtigl~t sil~ltirrg" 11or of a " (li~w11rise ", there werch on other oc~rusions iil)l):~~'c~rtt indic:i~tior~n thitt the scatterers tended to move illld ;Lgttill & T ) ~ ) P O B Cf hf ~ sllrfa~e just s o l l ~ c ~ ~cI0wlI ~~ib wiLrd t iLf'f('l' stlll~(~t prior to s t ~ t l r i ~( tiuzit8iL, 1961). e [n the W L L ~ ~ Coff ~ I ' Ssoutll~rnCitlifortlitt t)uthyscapli divers confirmeti t list CCI~O('Soft,ett came frorn the depth of 400-500 rn where they saw so lrli~ny~Se~geste~ sirnili~ that they cotlld not cou~ltthem (Dietz, 1062). this iLn>iL~S'ergesteswas aor~sistently associated with the lower t~otnponr~lt of t scattering laycrrs (Barharn, 1963 ; Clarke, 1966). According to Snlith ( 1 !)54), 13 in tlividuals or more of tt palaemorlid shrimp, Yalnernonetrs vu,lgaris (Say), must be concentrated in 1 cubic yi~rd(17 i11ds.lrr13)in ordtbr to be recorded as tt sollie scattering layer. A s tho i ~ ~ . c of i ~ sitconstic cross-section of R~rgestessinzilis and Sergin iLrc i\l)o1111-8 t i r i i t b , ~greater t11i~nthat of F"~laemo?~~tcs vulgaris 11cc.~ns ( ~ i t l v ~ ~ l ~ILSi ttht\ ( ~ ((Iorst~I l iLrCit of t h specivs), ~ the popnlittion tle~isityof i L scattering itt I ( ~ : L s 9~ illtls./rn3 is ncc:chss:lr.,yfor tho sl)(!(-ic:sto co~istit~ute li~yor. I 11 fi~ct,,it, is suggcst,td t h i ~ tI~otllspecies form scvc:ral small l)op~~lt~tiotl cier~sit~ within a conll)~~('t swiirrns i l l tJ1ct xtxii; t l l v i~('tt11~1 20 irl
\'. ( ' 0 1 , 0 ~ ~ 1 3 . \ N I ) ~ ~ ~ O I , ~ ~ J I ~ V E S ( ' E E ; ( ' E ITsrri~lI~tlu. s l ~ l ' i r l ~livillg l ) ~ i ~ t . ) ~ ) ~ l500 s 700 111 dcptl-I by day arc. t ritrlspt~l.t~l~t 01- scbrnit,l~iulspitt~~~it wit 11 scant t cr.ctl rcd c.hrornatol)hores. At i~l)ol~t, 500 700 111 i \ s~l(lde*l~ fi~l~nitl c~l~allgc' occurs, the upper rnesop(tlt~gic.sl)tv~ios1)(bi11grcb1)larcd by those Ilaving u typically uniforrn is not distinct ill younger scal.let,-l-c~cl ~)igtticwti~tiot~. 'I'l~epigrnc~r~tut~ion tarns lrtl in r~tlrrlt~ with increitsing tlcpth stirgegex, ir~rtt Ilt. 1)odj.grr~~lt1i~1I.v of httbitrbt,, i ~ ol)scr\-ccl s in A'!j,vt~~llrc.9pis debilis. 13u1~I~cr1t~oi1tl ( 1 !14'i, 1 !)40) i~n(lYidtlwy~i( l!j57) hnvc shown that in thr gtSc.l1rls S(jr.!/r~stss s. 1. tilt' l)t-eseri(c01-ahscwce of sl)ec.ializc1d Inminest.cXllt n~odific.i~tions of' I gi~stn~l~epatir gIitn(l (the orgitns of Pesta), i l l 1)ocly c.olour-itt,iotr.provide i~ nilt,uritl basis togt.tl~c.rwit11 \ri~t'ii~tiol~s of' twu S I I ~ ~ C I ~ O I ' I L'I1I1(b . n~~bgcnus I Y P ~ ! ~ P S ~S.P . S. S for t ht* r(\cog~~itioll 11th

2t N

.”>

.

(W)

D

H l d 3 0

(pnits H e t y w t c s i t ) t tiv p . r w w t t I I ~ I I K ’ V )itic.lri(las semitranspiirent species poss(-ssiiigo r p ~ n sof Pcstii. whilcx t h c siil)prniix Sergia (a dintinct genus i i i this p i p ~ r iric*lutlcc: ) slwies id ;L uniforrn r d pigmentation, without organs of I’t’HtiL, but it1 niiury viiws wit ti dertnal photophores whirh rcwmblc thc sit IiiLtioti fo u lid iI I (*(.l.tii i t i I twnopc4agic. fishes. However. t tic. o ( x w r ( w * c of su(*h scmii ribnsl);Ll.(’tlt s p i e s UH Bpryia lucems and S . kzZi,smani 13:irt~i~rtl in t h~ Svrqin rhullPtegori grolip suggests that the

definition of RPrqicc must3he tilt(wxi to itic~litdesotne species with only a watt(bring of red chrotnut,o~hor.cs. The verticd distributions of‘ t ti(. two gcincra are quite different. I lie spec.irv of Srr!lPstcs arf’ rwtrichxl to depths above 700 m. whereas LSurqin o(wrr froin n r t w t h c b R I I I ~ ; L C C to 1 500 m or more. There is a close cmwlat,ion hctwwn certikiri iLssociiitd morphologiaal features and tlcpt~hdistributioik. ‘l’tiiit is, the. spcciw with lenrs-bearing dermal photophores (8.c.hal1engrr.i group) inhihit, depths shallower than 700 m like Rergestps spp. Among them, those that appear near the surface ;It, night tire semit8ranspiwent,while others have a more or less uniform 1)ignicntation. The all-red species with photophores of the lens-less 6‘ opaqucx spot type (8.robuslus group) are generally found between ,500 ;mi I 000 i n , stid tliose without photophores (8. juponicus group) iwe tlistributecl iri depths of 1 000 i n or grclater. 1I7 he iLrr;qytntwt of the lens-bciiring photophores on the ventral ,l

”

surfme of‘ t h body tlifK.rs iiot only specifically but also sexually (I)enncll, [!)A5 ; Oinori, I U(I9iL). ‘l‘tir shape and arrangement of the organs of I’(\StiL t i r ~illso of qwt(>rit;itivsigiiiticww at species group and sperim I(~ve1s(Ifoxton, 19721~). Obstwratiotid t ~ n d cq)eriirwntiiI (liltit relating to deoapod bioIiitnincwwicc I I W surprisingly s(~iiiit.‘I%(* luminous secretion8 of Oplophorax spp. t i n t l Accinthpph!pi spp. h;iw easily been detected on deck when captured. Howev~r,tdrwst iLll efforts to stimulate the photophores to twtivit.v liuvc. proved unsiic s~fiilthuR far (Harvey, I931 ; I)etiticll, 1W5 : Ornori, 196!h). A scri~sof speotrophotometer testa has wcently Iwtw (*iLrriedout on tlirchc speries of shrimps to determine if t h y redly Iurnincsc~c. Some iirtlividuitls of Sergiu Zucen.p and S. prehensiZia showc~dpositive response when illuminated by light with a wtivelcngt 11 of 460 nm, b u t (ientmlae purvus did not show any positive indication (Ornori, unpublished). According t o Terao (1917) who described i n (letid the histology of the photophores of Sergia Zucens (as Rurqmtes prphandis). the species emitted a dim. intermittent. greenishyellow light. I)en~ieIl ( I 955) confirmed the radiation of Oplophorw spinosux ( i t s 0.!/riniuldii), Hgmenodoru yracilis, A‘ydellaspi.9 debilis. i’wrupandnlrcs rkhnrdi itrid several s p e c k of S’ergeste8 and 6SCerp%: the

orgib~rxof' i~ or A \ ~ P ~ ! /rr/lnrtlic.~t~s P s / P ~ sl1owc.d s t c n t i ~cmissioli ~ of blue pl~ot~opl~orc~s of Seryic~8ple~tder~s (as ligl~tfrtiut ly 1 ingt%clwit,l~gl-rc'rl ; S f ~ , g ~ . ~ric-ltrrr(li) tc.x flatsl~crlgrc*cllish-l~luc. light irregularly, and those of ,S~r!~i(t r ~ h t t ~~ ~t O~ (/I ~I I DI 11 ( Y~ t , ( ~ i(l11ll-gr(\e11ish ~(l~, glow. In S O ~ I ~species C of' Af*c~lrs thorc. i1r.c. t,wo or I I I ~ I . ( *pi~ilnof' l-c~lspots, onc priir oti the hiisit1 U ~ X I I I ~ of ~ I Ith(> ~ 11ropo(1il11(1 tllv o t h ~ r son its endopocl. Okada (19%) considcv.c.tl t hiit the. f1111etio11 of thcsr spots, c1c~sc1-ibed i ~ stail-organs, 111 this c:o~tt~cbction, Dr. A. K. Thsm (personal may t1c1 l~l~c)togt*nic. c:on~~l~u~~ic;~tioii) il~ti)l.lnt~cI nlc t lriit fishe~~lne~l of the Malay Peninsula 1oc:nte t 11o ~ ~ o ion s i t of' Irl rgch swi~ l-nls of' A r ~ t by ~ s their 1i~rninescencea t night. IJwifir+i~lso~ ) o s ~ i ~ si~sS(~~VsI I C ~ I Iof W possibly l l ~ r n i ~ ~ funct,ion ous in t,hv tc~lso~l, wl~icall Ii1114ic!n1.oatl ( 1 !):37) hits tlcbsori botl tis i i rrlriss of ~(41s n~rrro~ll~tl~~ti [by c~l~ro~~~t~t,ophorcs. I)(!nl)it(' tl~(bI I ~ L I I I C ~how(w(1r, , no oncl tiits sc*clri trlrc&ligl~t,of' I1'1~i'if~r. 1I 1 l ~ c . sl)(\(+t,~*i~l corn~)onit,iot~ of' t IN' I I I I I I ~ ~ ~ - H ( ~ C of I I ( +s11riln1)s P has not I'cbst

t , h c h

II~*PII ~nc-;~s~~rcvl. but V ~ L ~ ~ O Isl)c~(*i(w IS ot' iwphiti4siicls a~ntlmyc.ttophids halve tit~rnor~st~t.t~tt?cl l)~-in~itry ~ ) ( ~ i i In ~tshoir luminc~,clcencc~ vcry close to 4 74 I i\Icusurc~mt~nt of the i~~tcbnsit~y of emission are available ot' Ac(~tttheph,:lj'ra puypurea. 2- 8 x o111yfo~.t l ~ c .lulninous sc\c*t-etiol~s p\l'/c.n~%tttit dist-t~l~c.c~ of' I 1,) (Nicol, 1958) and A . pelngicn, I 1.2 x I 0 - 5 p\V/c*~~l "i~t I f ) ('1r1 ((:Ia~rk(ttat ul., 1 !)(iS). The light intensity from photophorchs 1r111stbv rnuc~lilowtlr t ha11 tJht?sc*values. 11 I h o r ~ h;t.vth 1)t:ibt1 viiriolts st,i~t,ernrv~ts otl the fi~nction of biolurni~lcsc*c~~c*c\ illaludi~~g prey i ~ t , t r ~ ~ c t iattractiori ol~, for swarming or mating, grey i~voidi~nc:cb a ~ ~ iillltlninution d of' tlie environment. Fraser ( l !)ti%) ~ I I ('l;~rI;(~ I ~ ( I !Hi:#) s11gg(~st(1d t li~lt~lninltllsJ ) O W C H S ~ventrtil ~~ opt~ol-es~~t,ilizc t110 t'tnitt,c'd light which shirle(l dournwarti aLrrtLys ot' ~)liot ~ L NiL ('Ollllt(~l'-sllltdillg 111(~('1llLlli~lrl to ('I'iLSC the 8itilollcxttc..i t ~ O ~ ~ Othtlt W S i l l thta ~~lc*sopcblt~gic. zonc., wl~c-I-(.light froin tllv nun is highly rlirc~c~tiot~iil of' a ~ n i ~ n t l ltire' n c~xtrc*rnc~l,y low, thc: shl-irnjw 1111(1thc visllii1 t,h~'(~sholds lyir~gI~(-fowthcrn. I?oxtor~(1!170h) ~vorlld I)(. illvisil)lt~to })rfxttt~lo1*s ntat,cscI tlrt~tthcs f'1111ctio11 of t hi' orgalls of I'tast:~ of , S C T ~ P R ~ Pi . rS ~' iiHhOviati011 with a1 st~1nitri111nl)ure11t botly provitles strong sril)port for this c*c>n~iter-.rha~di~~g f~ypothi-sis. 111 this c~o~~l~(>c*tiot~. r e ~ c ~ l ~ tN l y1r. .J. 14'. \\'iiltel*s (pt.rsonal caortl111~1aic~iitioti) t'our~tl $111 intft~~.cbstit~g fi3i1t111.c.of' the organs of Prst:l. to I l i n ~ ,S(~lgcs1ractrritcrt~s;irltl 8. rrect~cshave the ability to A(.clorclit~g is alwt~yspointed r ~ t ~ tilth t e orgilt~s01' l'estir no tl~tltt,he ill~~ttlination ~OWII\VILL'(I ~*c~gt~~~dloss 01' 1II(L ori(h11tilti011 of' tll(1 itnimal's body. I have c*ot~fit-rnc~c~ t liis rilc*c.Iit~tlistn in ~S(~r!qc~,~/cx .c.ittti/isar~cl8.~ernittwdl~a Hansell, sligpcbnting t l ~ i this ~ t t~(Iiil)ti~tio~~ is (+otti111011 in ill1 members of the gelllls (Pig. 1 1 ). 111 t tic. acliiari~~tn A'. sit)tili.v swi-Lm 1)oth obliquely ilnfl

FIQ. 11. Photographs showlng the ability of Sergesles 8 i ~ i Z i sto rotate the organs of Pesta. [ T oface p . 202.

horizontdly, t i i i d the iiit,wiitLl I i i n i i i w n w i i t tisnw of the shrinip waR itsunlly direct c d ttowtiwltrd i i r i l t w t i r i iiiig:lc of inclinutioii of the body exceedcd i h u t 50” with thc hOri~,0tlt,idplitii~.Dr W . 1). Clarke (personal cornniiiiiic,ict,ioii)iiot,rd that uwurtns o f S . s i r n i h off California, observed swttm gently in an oblique or through t h window of submt~ait)k*, iic-arly vorticul positioii with head l i p . On the other hand, underwitter flash 1)hotogribl)hsof A”ergia lurcns suggested that the majority of‘ this species wertb swimming in horizontiil positions (Ohta and Omori, 1 !I 7 4). Neverthc4ess, if the ~:ountc~r-shucliiig hypothesis is valid for all photophores of’ the upper mesopelagio shrimps, it must satisfy intiny theort~ticdobjections. For instance, the light emission of an tuiimctl milet, be s h t d y and the mima1 must have the ability t o adapt, either by migrittion or controlling photophore funrtioning, to cyclic or short term variiltionu in ambient light. Migration suggests itself as the obvious brhavioural response by which an animal could maintain itself in il constant light regime, but so far neither type of control has been ciescribed in the shrimps. If the luminescence really serves as a rec.ognition sigiiiLI by which individuuls of the same species maintain (*ontact,iri Rwilrrning or u t mating, thr intcrprotation of the hypothesis becomes difficult. The hypothch uppcitrs unlikely to explain the f‘unction of photophores that o(:(:ur in the lower mesopelagic species. I n the depths where the ariirnills are distributed the light produced locally by the bioluminesoencc of living organisms could exceed the prnetrntion of daylight, thereby rendering such R counter-shading rnechttnism ineffective. The tlermal photophorcs may function as light reflectors or receptors. Foxtoii ( 1 970b) mentioned the rolc of rhromatophorev of semitmnsparent Rhrimpe in relation to the funotion of the photophores. [n this connection, Sergin Zucens ilppcars to have the ability to control the ohromntophoros in r e s j ~ o n ~t oe chitnges in background colour and illutnincttioii. The shrimps (.aught near the surface during twilight are Iurgely traiiapsrtwt, while those collecttad a t 200-300 m depths are more heavily pigmented. The fuuct ion81 significance of the nniformly pigmented red integument of the lower meso- and bathypelagic shrimps is obscure exvept in so far as it renders the animals inconspicuous and possibly aid8 in reducing the surface reflection of light produced by iicarby orgtinisnis (k’oxton, 1970b). W&h uncl Cliace ( 1937, 1938) studied the relationship bctwecn thc vorticd distribution of certain specie8 of sergestids and oplophorids and the size and structure of their eyes, and found that and flt~~tellaspi8 the eyes of sprcica in the genera Sergia, OpEopho~u~ t h c b

264

MAKOTO OMORl'

possessing dcrmtrl photophores w e larger in proportion to body size than the eycs of other specios which lack photophores.

VL. SHOALING The distribution of maiiy dirimps is uneven and patchy. Probably, shoaling may rcsult primarily from the interaction of the shrimps with each otjlier, although its mechanisms and functions are not well known. Clutter (1969) studied the structure and function of a hypopclagic popultition of mysids. H is observations suggested that the social bohirviour of the mysids could be interpreted as related to maintaining position within their habitat, reducing predation, increasing probability of copulation, and regulating population. Nothing is known about the social behaviour of the shrimps, but many species which have itnage-forming eyes and a set of luminescent organs must be able to congregate to facilitatle mating and regulating population. In copepods and euphausiids the shoaling behaviour is significant in herbivorous species living in the surface or sub-surface layers. Although decapod crustaceans are not herbivorous when adult, penaeids and sergestids feed on phytoplankton during the early larval stages. Gut contents of Sergia lucens indicate that even adults eat some diatoms in certain seasons. Post-larval pelagic phases of the genera Jlunidn and P1euron.codes often show the capability of grazing, by filtration, upon blooms of the l q e r phytoplankton organisms (Longhiirst et nl., 1867). These facts indicnt,e that the formation of vast shouh tippears to be characteristic of fil ter-feeders or potential filterfeedern. Although the relationship between observed behaviour and feeding habit cunnot be interpret,c!cl fully, the function of shoaling in these kinds of animals, particitlarly by the larvae and juveniles of the shrimps, seems likely to help control their population and to maintain position within their habitat zone. As the population becomes larger, the shod which i R composed of swarms and schools becomes larger. However, since the witable habitat zone is limited, the density of the species becomes higher, and by physical contact the individuals will always be able to relate their population size to the amorint of food supply in their own zone. Then, regulat,ion of the Rhrirnp population, if necessary, will be taken care of by cannibalism and predation. Also retardation of growth of the whole population due to lack of food may cause restraint of reproduction. The meso- and bathypelagic carids are carnivorous throughout life aiid are unlikely to form great shoals. Our samples indicate that thcy Hometimes congregate in small swarms conrristing of a few individurtls. The distance between one swarm and another appears to IN

TliE I3IOLO(IY OP PELAGIC! SHRIMPS 1N THE OCEAN

265

considsrablc. Their swarms art’ most probably maintained to increase availability for c.opulation. An ext~nrordinarilylwge population of Sergia lucens is maintained throughout the ycw in tho tiorthcrii tind wostorn parts of Suruga Bay. The locality of the shoals vtwks dcprntling upon the stage of growth. The snialler swarms in u shoal tcnd to bo compoRed of individuals of the same size group. Observation indicated that eurlier post-larvae are Licparatmd from adolescents and adults, and their swarms are usually found offshore. The adolescents swarm more or less widely both in shallow, innhorc arem and in rather offshore area. The swarms of adults ure rnostly located on or around the 200 m isobath near the mouths of rivers (Fig. It?). The shoal area on any one night is usually very localized, at best 8 km long and 2 km wide, lying along the cottst. The bottom slopes steeply from close to the shore. The flow of water from the land causes a strong internal mixing of the salt wedge, and the area contains rich nutrients which promoh the production of the food of 8.lucene. The bottom contour is complicated and the sea-floor is covered with fine mud. Among shoaling areae, the environmental conditions for 8.lucene must be best near the mouth of the River Fuji. Although tho detailed relationship between environmental conditions and swarming behaviour remuins to be studied, the largest shoal is uaiially observed in this area. When the population den8ity rcachen a11upper limit,in the shoal areas, the remaining animals scatter in adjacent waters. The Bwarms may have been more discrete than aa indicated by the samples. The size and population density of the swarms of Sergia Z~ucen!ns appear to become largest in early post-larval stages. The density of adults in the swarms is grcatcst in early summer, that is, just prior to or during the early spawning season. Similarly, in South India the Itirgent gregarious swarms of Acetee erythraew Nobili and A . ~errulduejohni Nataraj appear in the coastal waters during their ~pawniiignctmon from January to April (Nataraj, 1947). Thew phenomena arc’ 110 doubt the same as the pre-Hpawning aggregations of euphausiids which have been noticed by many workers for e long time und tho o(*ourrcncesare probably related to physiological changes, such 88 copulation ~ n egg d production, within the species themselves. The amoiint, of light penetration in the sea also appears to affect tho shoaling behaviour of the shrimps. In the surface layers very noticmble swartns of Sergia lueena usually persist during the fht few hours of darkness and at or around moonrise, moonset and just prior to sunriw, suggesting that visual rues and illuminations stimuli are iinportant .

260

MAKOTO OMOLLI

Surfwe slioaling is a wrll-known phenomenon in several euphausiid v p e c h , thr. rwortlq of wliic*h ~ ~ L Vbcen P summarized by Komaki ( I W7e). Acc*ortling to him, t lie mixing of cold water masses with warm wttstal wthter protlucen contlitionx cotiducive t o surface swarming of Itwphawsiu pacijicu Hailsell, usually tit, the margins of cold masses in Japanrse c o t ~ s t ~waters. l It, is noteworthy that the large shoals of Sergesks sirnilis in the surface layers usually occur in the transitional domain just north of the subarctic boundary where the surface isotherms show complicated tneandering and that the species apparently tends to forin dense swarms at temperatures near the upper limit of its range (Omori ~t d.,1973). Calunus l o n s u ~Brady (Kawamura, unpublished) arid fluphuwiu superba 1)ana ([vanov, 1970) showed in this connection a similsr beliaviour in the subantarctic region. These phcnomena are presumably common features of the shoaling of planktoiiic crustaceans. Evidently, the intense mixing of waters having different environmental temperatures in the surface layers causes physiological and possibly physical effects stimulating the species to swarm. The population density of adult Sergia lucens in the swarms is tbstimat,ed to be 20-176 inds./m3 at night. That of Sergestes sirnilis, tlcrivcd from the feeding data of fin whales, is 100-4 500 inds./m3 at iiight (Oinori P t el., 1972). ('onectitration of Acetes spp. in the neritic waters or cstuttries iritiy exceed tliose values. but the densitics of the occ*uiiir shritnp are generdly low compared with those of some of the c~uphuiisiids.The density of lluphriwia superhn in swarms was spproxiriirttcly 6 1 000 inds./m3 (Marr, lW2) and that of E . krohn,ii (Brandt) WLS about 31 000 inds./ms (Baker, 1970). Forsyth and Jonex (1966) recorded a deiisity of about 600 O W indn./rn" in a swarm o f Thysnnoe,Ywn lwigicuudiitu (Kruyer) in the Shetland Islands. The ecqlogical rolc of the anitnalx in the areas where they form great shoals niiist be different from that in area8 where they are sparsely distributed. The shoaling animals may play an important role in determining the abundance of prey species and competitors, and, hence, in determining the cornposition of the zooplankton community within their habitat. 'l'herc. is i~ suggestion that swarming or schooling may reduce predntioii by decreasing the frequency of contact with predators t m l by enhimcing evasion aftzer contact (Brock and Riffenburgh, 1W0; Clutter, 1969). This consideration seems to be true, as Brock imd Kiflinb~rgh(1960) mentioned, when the size of n swarm greatly tweeds the cluantity th;tt a predator can consume (e.g. sergestids vcwu8 rnyc~topliittnor wphalopoclx). However, in some areas tho

swarms apparently attract morv larger, vorwious animals and becornt* the object of heavy predation. Thp shrimps would not be eaten by baleen whales unless they made large homogeneous swarms of heavy concentrations or patches. Elsewhere in the North Pacific fin whales take both copepods itnd euph;riisiids, i t n t l sic4 u~halesfeed diicfly OII copepods. Although there W ~ L H1 1 0 i n t l i c - i i t i o n tlliLt the stiLntling stoc:kn of these food animals decreased, S ( ~ r y p s l p s s i r d i a was preferentially eaten by the whales where it swarmed in restricted areas south of the Gulf of Alaska. Sergia Zucens comprises the bulk of the diet of many fishes occurring in Suruga Bay. The predation by fishes appears to increase with increasing population density of the shrimps in swarms, and i t becomes highest in early summer (Kosaka et aE., 1969). These facts indicate that without considering the peculiar shoaling behaviour of the species and their social life, discussion of the food chains and biological productivity in the sea is not very valuable. The ecological significance of the macroplankton and micronekton communities is indeed different in this aspect from that of phytoplankton, which shows relatively uniform di~tributiono v w broad areas and reflects environmental effects within u relthtivoly short tinici.

VII. LIFN HISTORY For estimates of the productivity of shrimps from field measurements, precision and accuracy of sampling are critical. If the general features of the morphology, duration and mobility of each stage of development from egg to adult were clarified, we could samplc thc: species accordingly and estimate the true abunrlance of the arlirnitls in the sea. Need for more information on the life history of inclividual species should be emphasized to determine the principal laws in various life phases of the species through its development and growth. Our knowledge of the life history of pelagic shrimps is very scanty. However, there are numerous sources of information on the biology and ecology of shallow benthic forms, and these contributions arc very useful for study of the pelagic species. The life history ant1 other biological characteristics of the commercially important ponuc i (1 iirc reviewed in detail by Kurata ( 1 971). In this section data ohtainc:tl from the study of three pelagic shrimps, A’erqiu lucms, Acules j(iponicun i t r ~ t l Lzbcifer chacei Bowman, provide thc hasis for tlisounsion. 1

A . A‘pnc.un/ituy The ovaries of Sergia luccns and 8.challenyeri Hansen, lilte thost: of all members of the genus Sergesks. are located beneath the heart,

extentling froni the foregrit to the posterior end of the carapace. However, they extend into t,hc abdominal segment in some other species of ASergia, In Acrtcs spp. the elongated ovaries reach to the sixth ebdominul wgrnent. Tlw ovaries am visible through the thin carapace in the wmitranq)tcrrii t sprcies ; they turn from light yellow in the early stages of maturity to opaque bluish-grey with increasing development in Sergin luc~ns,whereas they become yellowish-green wlicn mature in Acetcs japonicw. I n the Penaeidea it can be determined whether copulation has taken place from the structural change in the thelycun~ (Rpermatophore receptacle), as Yoshida (1949) observed in Acetee. Generally, copulution takes place a few days before epowning. Tho morphology of the reproductive system is described in detriil for LSargPstes similie and Acftcs americunus carolinue Hansen (us A. carolinria) by Genthe (1969) and Burkenroad (1934) respectively. Exclept for Lucifer, which has clusters of eggs attached by short stalks to the third pereiopod until hatching (Brooks, 1882), all Penaeidea shed their eggs into the water. The spawning of Sergia lucens takes place in the shallow layers at night when females with ripe ovaries rise toward the surface. The egg laying is an intermittent process which lasts up to, 25 minutes. The eggs are spherical, light greenishbluish-greg, and about 0.25 mm in diameter. The perivitelline space is hardly seen in the egg throughout development. The eggs are mostly drifting in depths ranging from 10 to 50 m where they were spawned, because they have a density similar to that of seawater. Measurement,s in the 1iLborutory suggest that the eggs float upward u t about 22 cm per hour in wiiter of 32"/,, salinity a t a temperature of 22°C. The buoyancy rate, of cour~e,decreases in waters of the same salinity but of lower temperuturc*s. As the time elapsing between sptswning ot'the egg and hatching of the nsuplius is 24-36 hours under normal cunditioiis, the ctbovcb buoyancy rate would cause eggs at 30 m dept,h to float to 22-25 m ict, the time of hatching. Eggs of Acetes japonicw me green and planktonic (Soejima, 1926). They gradually increase t h e perivihlline spwe and in the later stages of development they swell 2.0-2.6 times in diarnetcr. The egg8 of Caridea are incubated by the female and are attached to spccialized setae on the abdominal appendages (see Yonge, 1955). The eggs are generally elliptical and large, but the number of eggs is few compared with that in Yenaeidea of similar size (Table IV). As pointed out by Gurney and Lebour (1941)) the genera of the Oplophoridea fall into two groups according to the size of eggs. Eggs of O p l o p b ~Ephyrinn, , Hgmenodora and Systellaapis are much larger than those of Acunthephyra, Meningodora and Notostomw. The

TllN tt10140(lY OF PELA(;HC StfHIMPS IN THE OCEAN

269

number of eggs curried by a female in the latter group is much greater than that in the former group. On the whole, the lower mc'so- and bathypelagic species produce lurpr but fewer egg8 and larvae rclative to the epipelagic species. This rneans that the large larvae hatched from the large yolk-filled eggs survive with internal yolk alone during their long journey to the shallow layers where there is a rich supply of food. After metamorphosis they can utilize a wider range of material aa food. I n any one species a large female spctwns a larger number of eggs than a small female. Therefore, the nurnbcr of eggs produced by a decapod crustacean is dependant not only upon the volume of the eggs bnt also upon the size of the parent. Generally, the number of eggs per female is a linear function of the size of the female (Jensen, 1958). Measurements and counts of the eggs of twelve common species of penaeids and carids reported in the literature (Kubo, 1951 ; Jensen, 1958; Ikematsu, 1963; Apollonio, 1969; Omori, 1971b) suggest that the maximum/minimum ratio of the number of eggs produced by a female in one breeding season at one locality varies from 2 to 10, with an average of 4.5. The weight of the ovary in Sergiu lucens is equal to about 11-14% (average of 26 specimens, 12.5%) of the body weight of the parent and that of 8.prehensilis is 1613% (average of 21 specimens, 11.4%). I n the pelagic carids the proportion of the weight of the fertilized eggs t o the total body weight (weight of the eggs plus weight of thc: purent) was 10~0-10~50/,in P a . ? i p k a sp., 78.O%, in Oplophorus graciliroatris A. Milne Edwards, 7.3%, in 0. spinosua, 9.5% in Amnthephyru cximia, 11 -8% in Notostomus japonicw Bate, 13.2% in Iiymenodora froiitnlis, 7.4% in Systellaspi,? braueri (Balss) and 9.7 % in S.Zanceocnzufuata Hate (Omori, unpublished). Sergesles siwilis in Monterey Ray spawns in December-January and in Jiine-July. and two overlapping size-groups undergo the same developmental history but six months out of phase (Barham, 1967). According to Permy and Form (1969) the species spawns throughout most of the yew otf the Oregon coast. However, young shrimps were not uniformly abundant, suggesting pulses of spawning in spring and wintcr. Matthews and Pinnoi (1973) state that Seryestea urclicw breeds in spring in Korsfjorden, Norway. In the temperate waters around Japan the spawning of shallow benthic penaeids is usually heaviest during summer. That of the carids generally takes place in spring and autumn (Yasuda, 1957; Ikematsu, 1963). Like the penaeids, the spawning of Sergia lucena in Suruga Bay (35'N) occurs from late May to mid-November, and it is heitviest in June-August. The spawning starts exactly after

270

MAICOTO OMORI

oriviroiiniorititl kmptwiturcn (20--iiO m depth) excced 18°C (Omori, Miito i ~ i i d Kw4,src, unpuhlished). Tht! spawning season of Acetea japorbicu,u;in the Ariiiki! Sea (33"N) bvgins at about the end of May and Lists until early October (Ikematwu, 1953), but' it occurs from late July to August in the Yellow %a off west Korea (38"-37"N) (Yoshida, 1949).

In thc tropical region off Houtlzcrn India (12"-8"N) Acetes erythmeus iiritl A . serru1otu.s johrbi possass mature ovaries from January to April (Naturaj, 1!)47), aid the plankton collections from October to MLwuh Itre rich in the larval forms (Menon, 1933). Le Reste (1970) reports thiLt the spawning of A . erythrneus in Ambaro Ray, Madagascar ( 13"s) is htwviest in Novembor-March. Spawning of Acetes australis Colsfax (possibly u synonyin of A. eihogae Hansen) is supposed to be heaviest. (litring mid- m d later summer (December to February) in the l'uggeruh Lake (33OS), Australia (Morris, 1948). Apparently the spawning of shallow-living penueids and sergestids in the temperate region is related to temperature. Whereas, in the tropical region the spawning almost certctinly occurs throughout the whole twelve months of tnheyear, but the occurelwe of rich larvae along the coast is probably related to precipitation and wind direction of the monsoons. As described later, there are two types of generations in Acetea japonir*us, namely, the winter or long-term generation and the Ruiniiier or short-term generation, and the durations of the two spawning~overlup (Ikematsu, 1953; Yasuda et al., 1953). Females of Bergin lucens produce eggs during one spawning season only. However, no proof has so fur hecn obtained to deny that IS. lucens produces scverul broods in one npuwning season. This species often retainR coiisidcrltble number8 of imrnature ova in the ovary after spawning, as observed in various penseids. Although it is not confirmed yet, the possibility liits been pointod out that in the penaeids these small ova develop later and produce a second spawning (King, 1948; Ikematsu, 1955). Newly hatched larvae of S'ergia 1ucen.s oceur in the plankton of Suruga Ray from June to November but the abundance is not the mme t'hrorighout the whole period. There is some tentative evidence to suggest that occasionally two spspctwnings per female occur in a year. The first clutch is produced in July and the second clutch in October, when large quantities of food were available and moderate environmental t,emperatures prevailed. Presumably, the carids produce a sequence of broods, A female of h@$M%" sivado spawns twice u year, in early summer and early wint
TI1E RIOLOQY OF PEl,A(ITC SHRIMPS IN THE OCEAN

27 1

September. The first clutch contains more eggs (average 83/fernale) than the second (60 eggs), probably duc to reduction of the female reproductive capabilities (Apollonio, 1969). Matthews and Pinnoi state that Y.vruultidentata from the coast of western Norway breeds throughout, most of year with indications of greater activity in MayJune and iii October. It i R mid that, after each spawning these species carry egg8 for about five months till hatching. In contrast, with the above-rnentio~~edshrimps inhabiting the epipelagic and upper mesopelagic zoneR, the spawning seaaon is not restricted in time in lower meso- and bat hypehgic species. Probably, spawning takos place during much of t h e year. Aizawa (1968) supposes that the spawning of Acanthlph?yra quadrispinosa is prolonged from Mttrch-April to November-Decembrr mtl thttt hatching takes place between December and May. Off Bermuda, females carrying eggs with advanced embryos and free-living young of several lower meso- and bathypelagic ciwids are found throughout the year (Chace, 1940; Gurney and Lobour, 1941). The absenoe of a marked seasonal breeding period in femalca of the lower meso- and bathypelagic carids might be related to the fceding habits of the early larvae; they do not feed on phytoplankton in the euphotic zone but can probably use a wide range of mctterial as food and adopt the diet of the adults fairly quickly. Muuchline ( 1 972) cliscusud the preRence, or absence, of seasonal breeding cycles in &thypelagic crustaceans. He showed the possibility that, in bnthypelttgic species, the final stages of maturation of the oviiry coulcl bo dependent upon mating having taken place, and therefore the state of sexual maturit,y of males would provide evidence as to whethor or not seasonal breeding occurs. Tho sex ratio of Sergia lucrns is generally 50: 60. I n the early spawning scasoii, however, females arid males tend to live separately, and u marked diacrepancy in t8heRex ratio occurs according to locality in May-July (Omori, 1969a). Apparently the females swarm in shallower c t ~ of neritic water than the males. Thc sex ratio of A ~ e t r n ~ j a p o n iand several penaeicls in the Ariake Scti also fluctuates during the spawning season, and Ikenuitsu (1953) attributed this phenomenon to early death of the males after copultrtion, because the ratio is generally slanted towards females in the commercial catches. However, such variation was not observed in A . japonicw in the &to Inland Sea throughout the year (Yasuda el aZ., 1953).

B. Development Our hiowledge of the morphology of the larvae and juveniles of pelagic shrimps is severely restricted by the practical difficulties of

TABLE I\'.

Speeics

SIZE OF

Averege egg diameter of f i n d etuge

EGG-4ND FECCXDITP OF PELAGIC

Surnber of eggs i n one brood

(mm)

SH€lI\rPS

Carapace length of ovigeroua female (mm)

~~

Sergcstea sirnilis Sergiu lucens Acetee cochinerlsis* A . j a p ni c ua Pattiphueu multidentcrto P . sivado P . sp. Parapaaiphue siclcatif rons Oplophorus gracilirwtris 0. +nicauda 0. spirwmcs 0. typpw Acanthphyra e.&rnia

0-23-0-33 0.25-0-27

1 700-2 300

4

047-0.50t

0.26 2.6 x 4.0 x 1.8 x 3.0 \ 4-2 x 2.6 x

2.0 1.5 1.3 4.0

2.6 1.9 3.5 x 2.5 2-9 x 2.1 1.0 x 0.7

11-17 10-13

680-6 800 40-1 20 131-172 25 16 8-9 29 6 990

3-8 18-30 14-20 20-22 32-26 15 7-8 19 12-13 41

Pearcy and Forss. 1969 Omori. 196% Rao, 1968 Ikemateu, 1953 Apollonio, 1969 Williamson, 1960 Omori, unpublished Smith, 1884 Omori, unpublished Hayrtshi and Miyske. 1969 Omori. unpublished Haynshi and Miyake, 1969 Ornori, anpublidred

A. gracilip A. i n d d A . purpurea

0.8 (long) 0.75 x 0.65 0.82 x 0.84 1.15 x 0.75

A . quadriapinoaa A . sanguinea Men inyodora mdlG S O h ? b ? n U8 $ l ~ n i * s U S

Hymenodora frontalis H.glaeiulia H.gmeili.3 Syatellaapia braueti S . debilia

12 9

700-1 540

0.8 x 0.5 0.9 (long) 0.92 Y 0.72 3.3 >( 2.6

8 014 19

3.0 x 2.0 2.3 x 2.0 4.4 2: 2-8 4.6 2.6

22 1 &20

14-17 23

S . 1atleeocaiidat.a Parapandalita zuratroesen i Physetocaris micropklhalma

46 320-380

~~

~~~~

* Possibly a synonym of -4. japo,ricus. t With large privitelline speoe.

~

10-17 15-li

~~

43

14 16-19 9-1 3 23 14-15 19 7-8 8-9

Chace, 1940 Hayashi and Miyake, 1969 Gurney, 1942 Aizawa, 1968; Omori. unpublished Hayashi and Miyake, 1969 Chace. 1940 Omori, unpublished Omori, unpublished Wollebaek, 1908 C!hace, 1940 Omori, unptiblished CoutiBre, 1906 ; Ha>-asharid Miyake, 1969 Omori, unpublished Omori, unpublished Foxton and Herring, 1970

FIG. 12. Egg a11t1nat~pli~ls.Serp'a lucetur, n, egg: b. first: c, secontl lualrplius. .4rctecr corhinensi8. (1, e g g . -4cete.q joponicm. e, first ;.'t sooottd naupiit~s(a-c. after Ornort, 196%: d, after Rao, loti$; o, f, after Soejima, 1926).

TIIF. HIOI.OQY O F PE:lAA(lICYHBIMPS IN THE OCEAN

275

Itwping npwirncws tdivc? uiider lu1)orHtory conditions. Undoubtedly. this oauws grtBtLt, difficulty in t l w cw)logicd stutly of the shrimps during the larvtd stagiw 80 far, only a few observations have been made. by rearing, on ttia larvltl devc4opaicant of’ a fcw species of the genera Al‘argestes iind ASergia (NU~~IZIL\W, 1‘316 ; Uurney and Lebour, 1940: Omori, 1!)6!)it, I !)7 1 i ~ ) , Acstm (Soejiiiub, I!)%; Menon, 1933; Rao, 1968), 1,ucifer (Rroolts, 188%), I’nsiphnwc (Williamson, 1960), Oplophorus, Ac.n.n/hqh,yra iLi1(1 ,S!/Rtello,upiu ((A ririlc*y ; i d I,ebour, 1943 ), Accmtheph,!/ra (Foxton, lI)84; Herring, 1967) itntl I’hysctocaris (Foxton and Herring, 1970). In m m y ct~scsthe Iarvlte have been obtained live from the plankton. Thc eggs have also heen collected from the Rea or removed from the thlom inti1 nppentlages of ovigerous females prior to hatching. Recently the eggs of 8 m p s t e s sini,ilis, Rrrgia lzicens iml Lticifcr charei htwe been spawned i d hatched succesnfully under lahoratory conditions (l’enrcy tind Form, 1969; Omori, unpublished; Zimmerman, 1!)73). IIespite the number of shallow benthic! carids which have now been rctLrc(1 011 ntiuylii of’ Arteinin ~nlinntI,ctwh, very little is known about the nutrit,ionrd requirerncwts of the larval stages. The penaeids ant1 sergestids cannot! bc retired on Artmia alone during the early stagca. ‘I’lwy iiccd cliatomn or flugellnt,cs11sfood, but the choice of the best) Food is IIXIIUIIY ib miLtter of chthnc(b. Gordon ( 1955) disrusscd the close affinity between the Penaeidea, particwlnrly tlie Sergsstidae, and the Euphauniacea in their larval devclopmtwt rind adult structure. The Yenwidea are believed to be primitive tleccipods ; they ttnd thc Huphausiacea are the only Eucarida wit8hSince iittiipliiis larvue. The period of t h e between spawning and Iitbtching iii thc Pwacidett is rslutivcly short. Undcr normal environmcmtal tc~rnp(wt ures it tiLkcs about 30 Iwurs in A’myiu Ewen.9 (Nakazawa, 191(i; Oniori, 1971a) arid Arvtrs j~ponicue(Soejima, 1926) and 36 hours or more in Lucijcr f i i x o ~ i (as Lucifer sp.) (Brooks, 1882). They hatch ;is t~ naupliw nntl prow to maturity passing through protozooal, zoed and post-larval sttiges. The tiuiipliun is recognized by its three pairs of limbs, nttmcly itntc.nnriles,ant,cviiinearid inandibles (Fig. 12). TheAe cephalic appendn p s arc ull ntitdory a i d no other eppmdages are functional. The protozow (elaphocaris in Serpr&clae) hae functional mouthparts. The cnrtipace is developed but not fused to the thorax; the abdonien is scgnitmtcd from the second stage ; paired eyes are present, rtlthough they mty. not be functional in t3hefirst stage. Swimming is affected by ~ n c w i sof the ariteiinules arid the biramous, wgmentsd entennae ; thcl tnundibles have lost their natatory function, while ctxopods of itt Iwst, the first, two p i r s of rnaxillipeds arc setose and

276

MAKO1’0 OMOHT

natatory (Pigs 13 and 14). The liirvae swim with the head upward and forward. In the zoea (ttcant~hosorntti n Scrgestidae) the third rnaxilliped and some or ttll pweiopoda braonic fiiiictionrtl for swimming ; pleopods ttro absent, or rudimentary (Fig. l f i ) . The larvae usually swim tail first, ventral side up.

, ’

--. .

f

irti umtc~zoc:a. Act

The protoxoeal stages can Rwim with either the antennae or the exopoda of the rnaxilliped, and as far u.8 t,he functional difference in swimming is concertled, they are definitely intermediate between nauylittr and meal stages. Williamson (lOfiCJ), however, considers that they ttre morphologivttlly equivalent to the first thrm zoeel stages in tho remainder of the Decapod8 and he proposes to include the protozoetil stttgw i n the zoeiil stages.

277

THIC litOI,OOY OF PKI,A(IIO 811RIMPS IN THE OCEAN

\'-\- \

I

..

14'1~.

,Sr,rgrskt? cnriacc.cr/t&nt(f ti0 o~Imci~iiri type olaphocaria), R, finit ; I), +%wyf*Ikvv @ q # l t r d (th(*l[lJhr,l6 tylm nlaphooarla), C , firHt ; (1, WOOnd protozooa. Sergin lucens (t hv hispitlrt typo d~phi>ott~lM), o, firnt : f, w * o n d protozoee (a-d,~ t Qiiimey t ~and Lrhoitr, 1940; 13, f, ttftnr Omnrt, 1969a). 14.

i'rotoeciorb.

wf+Cr,titl }WOtlJXOOlb.

Ln the post-larval stage, thc setose pleopods on some or all of the cibdorniiiiil segments become functionul natatory organs. The larvae swim with the hcsd upward and forward. This phaRe consists of several &ages, which in the Sergestidae have been given the name mnstigopus. Cleneri~lly,there appears to be a rather gradual transition from post -larval to adult characters. Moultirig of Avergin lucens in the lahoratory was observed every 4 days in tlir ecirly post-larvae at an experimental temperature of 20°C, but was mostly every 6-0 days in the ttdulb at temperatures ranging from 23" t o 26"(:. Moat moults took pl&cf\at night. 4

u

11.-

12

10

278

MAKOTO OMOXI

a

b

,'

e

I

;I

!!

A ' u ! ~ ~ ( rorrcidthrn, w (1, Rrrt, Z(JCU. ,'irrr@e8 wiyilw. f i r d t ; e l . wroncl c o w : thircl p ( ~ ~ t - l a r v a
Y I I I . 16. %cicw t t n c l I), f i r v t

TJMIIL.

p(JHt-18I'Vu.

,+,:giu Zurwu,

0,

(3,

In t hc Peiitbeideu thwo arc always three protuzoeal &ages but the numlwr of iiiiriplinr and meal stages varies dopending on the genus and species. The nrtmbers vary according to environmental conditions, too. And even unclcr similar or identical laboratory conditions variability in the nurnhc~(if intcrmoults hiis been observed frequently in individual aninialx. Oinori ( IQ M h ) found that thcre are first and second naupliar

‘PIIF: RIOI.O(IY O F l’RT4A(llC SBILIMPY IN THE OCEAN

279

stages in S c t y i a 1ucrn.q iind tlic hitter dovelops gradually into a metaniLuplius without moulting. ()coasionallyno moult occurred during the nuuplius phaw (Nakwzawlt, 1 !)32), as Komaki ( I967b) observed in the euphnii~iidNctnntoscelia dijkilis H ~ i s e ~ i Species . of Sergestes and Bargia h w e trwo zocd st.agw (Wunsrrloos, 1908; Nakazawa, 1932 ; Gurney tml T,r.bour, 1!)41), i n Acetes there are throe naupliar stages and onc z o ~ dstage (Socbjirna, 1926 : Menon, I933 ; Rao, 1968). Lucifer hnnsmi Nohili hrts two zocsl stages (Gurney, 1927). On the other hand, Pctaliriiunt sp. (probalbly 1’. foliaceum), though the, nsuplius has not bwn found yet, has onc unique zoral stage which has uharacters intcwnctlitrtr htwccw those of‘ ttie ncanthoeomn and the mastigopus (Chrney. 192’4). C:cnv/,acEnsekgacns has four zoeal stages (Heldt, 1938). Tho nrcond arid third protozoeal stages of different species of the genus Bctyesfe,Y H. 1. sometimes look very different in regard to the structnre of thr carapace. Gurney (1924) and Gurney and Lebour (1 940) divided thc elayhocaris into three types, called dohmi, ortmanni and hispida respectively. The dohrni type have supraorbital, lateral mtl posterior processes with numerous long lateral spines, and the ortmanni type hnve lateral and posterior processes without laternl HpineR, h i t with long spines springing from the carapace a t their base. ‘l‘hc hispida type have ltktentl and posterior processes without long spincs; sonwti tnes with long spiiiiiles i L t base. Re-examination of thcir diitii suggost that the specie8 in the genus Swgeates excluding the N. r o r n i r d u m group (see Yaldwyii, 1957) represent the dohrni type; the S. r:ornlrdum group is of the orttrianni type. All species in the genus LSergiu correspond to the hiapida type. In thr Curidtw the eggs incwbatrd by thc fcmdes hatch into either il protomelt or u ZOCN (Pig. 16). ‘i‘hc protozoea and zoea YO grade into m e ttriot hor that 110 real morphological distinction is possible, and gcntmdly the etirly stagcbs of vuridetin Iltrvctc arc included in the term zoes. Incidcwttdly, the earlier li$rvsc of Systellwpis debilis swim, like thc zoeal stages of the Pcncieidcttt, back down and tail first (Gurney and Lebour, 1941). The larval development of Pasiphaea and Parapasiphue is seen to be very similar. Both genera have large eggs and iibbrevintcd ckvt.lopment. Previous reports suggest that there are four zocal atsgcn (Giirney, 1942 ; Williamson. 1960 ; Elofsson, 1961). The aurnbtir of 1ikrv:il stages of Acanthephyra is indefinite, but it is seven or more iii 1-1. purpurea (Gurney, 1942). Its poet-larval clevelopment has been dcscrihcd by Coutihre (1906). OplophoTw, Ephyrinn, Hymenodora and &ptellaspis, which have large yolk-filled eggs. show abbrcviitted development. There are five larval atages in H y m e n h r u glacialis (Stephensen, 1935). Probably Oplophorwr and Sy8tellaspis

have aborlt five zocltl s t a g t ~ ( i u r ~ ~ eand p Lehour (1941) suggested that tho gc?nrra with lttrge taggx arc, judged by adult characters of Oplophori(ii~c!,011t,ha wliole more primitive than those with small eggs.

V l o . 16. 1,nrvul fi)181nsof ~nrtd*. ti. l ' r ~ ~ i p h ~Wr~rI I~I J I ~ Ofirnt , ~ t n y t~~, ,lJ~1rtipt~Uliph(ie first stage.; 1 1 , Accmlhephyrrc attlcrit(frottx, first stago; r. rfctrttthephqrrt. rr~~ctzfrom, quodrispino.qtr, nocontl utngr ; (*, Arrrltthephyro purpureri, third ntage ; f, Hymenalorrc glrtcatrlt~, firqt stage; g. Syelelltlapie debilw, uocond atage. ( a , after W~ll~arncion, 1 H W : b, aftor ICernp, 1910h; c, nftmr Hrrrtng, 1967: d, after A~zawa,1968; o arid g, nfter <:ul?ic~ynnci Lebot~r,1941 : f, nftc~rStttphtanhon, 1935).

Howtbvcr. t h s suppression of lervltl characters during development is a form of pctrent.al protection and imparts to the larvae greater indept~ndenccof possible food shortages, greater switnming and feeding t~bilities,and greater safety from predators. Therefore they are considered as more advanced and well-adapted to the life in deep layers.

281

'I'llE IilO1,OOY OF l'l!21dA~+l(? SIIKIMPA ZN THE OCEAN

C. Croiuth. neat ~crify, long~rtityand mortality 111 Spr!liu lrieem the growth o f thc young is rapid and all larval Rt,ay;c.s awo cornplated withill a nionth ttftcr hatching. The growth riite after t,hc pout-larviL varics, dopentling 011 the sex and age. Usually t h o rttt,e iii fimales exceeds that in males, and the young grow faster than the adults. Growth is slowcd during the cold months, as observed

MONTH

Yitr.

17. (Ilowt,h trends of Scrgin lurene in Suruga 13ay and AceleR juponkue 8oa and fluctuation of thoir onvilwnmental temperature.

111

Ariekv

in various specicts of pentteids. Shrimps of this species take three or four months t o reach 20 mm in body length, and they mature sexually at ten to tfwelvc months of age when the length attaim about 40 mm (Fig. 17). They seem t o die within u few months after spawning. Thw the life epcm of tho species is about fifteen monthg, but n few individuals live for eighteen months at most under favourable conditions (Omori, 1969a; Omori el al., 1973).

282

MAKO‘PO OMORI

Bergin 1 u w v ~has bcen rcvwecl suaoessfidly from the egg to the fifth poxt-larvial s t q e under laboratory conditions (Omori, 1971a). ‘rhc larvae showed eonsiderahle tdertance to salinity changes, but the mortality wits signifioant1.v inc*rewscdat temperatures above 25°C and below 18°C. The growth rate of tho larval stages was 0.21 mm/day at 23°C and O . l ( i mmlduy at 20°C. The result of the experiments suggostod that the critical period or t,he peak of physiological weakness in A. lucens exists soon ttftw they begin to feed on phytoplankton in the protozoeal stages mid t lliat retardation in the development and growth due to lower temperirturcs IciLds to prolongation of this critical period. R e d c s ticirtjh from niitural abuses such ns rinfavourable temperature w d Itack of food, that rcsulting from predation must be considerable during 1 k r li~rvallifc: of A%Jrf/inl u r ~ n si l l nature. n a t s obtained from field smi plitigs t L n d from lil boriat,ory experiments suggest that the mortalit,v in the post-lnrval sttkges cannot be so great as that in the earliest stages. The death of post-lrrrvae during the autumn and wint,or is rnorc prohrildy CiLrisetI 1 ) ) ~lack of food and by predation, whiIe the tLdiiltnsciic chiefly irs tlic rcsult, of thc fishing or from their poor state of health :tftrer spawning. T)ctailrtl analysis of the mortality in each phase of life is being purwod at proscnt. There is some tentative evidence to suggwt, that, the atnolint of food available in the autumn causes fl ucturbtion in the niortdity of post-larvae and adolescents during the severe winter m o n t h (Omori,unpublished). On the whole, however, the greilteat factor affecting fluctuations in the abundance of X. lucens appears to be t emperature and the environmental conditions caused by tempcwtmv cliiring the breeding season. Omori et al. (1973) showed that, thcre is itti tapparcnt close corrdation between the fluctuation of catrhcs of 8.lzicens from different ycvnclasses and the water temperature ut around 50 m in the bay from June to August. There is also some iiidictttioii to suggest that thc mortality of Acetes juponiczcs is greatly influenctd by the temperaturc during the breeding season (Ikematsu, 1957).

From records of fishery statistics, Tanaka and Kawai (1967) used the methods of population dynamics to attempt to estimate the mortality of rS’mgh lucens. According to their study, 2-8 x lo9 individuals of Sergin produce 2-8 x 1012eggs in the sea during a spawning srttson; the number of recruits in the fishing ground is 40-200 x 109 individuals in November, 15-70 x lo9 in January, and 10-30 x log in April respectively. The natural mortality coefficient is 0.324 per month. I h w e some comment on their estimate of the population. but it will be discussed elsewhere.

TllE BIOLOGY OF PELAGIC SHRIMPS IN THE OCEAN

283

Swgestea nimilis is connidcwd to have i i life-span similar to that of Sergia Z~ioens( I%wham, 1967 ; 1’ctirc.y anti Porss, 1909). Off the Oregon coast it niiitrircx scxiicilly aftw aboiit, one ycsr when i t has attained a c~waptwlengt,h of 11 mm. Avtmge growth rate was hence about 0.0 mtn cw;qxtet* length p c ~month, but that of early post-larval stagw W:LX almost twice the overdl average (l’earcy and Forss, 1969). ~Seelyestesa r d i c m from off Norwtiy also bccomes mature when a year old tind cull livv nearly t w o yews (Matthews and Pinnoi, 1973). Genthe (1969) states, however, that S.similis does not maturc in one year in the Santct Utirhttra Channel, but, relewes a brood in the second year in the eiimmer untl autumn, anti then dies. According to Ikematsu (1953) the summer generation of Acetes jnponicus that l \ i ~ t d ~ in e s MtL.y and June grows faRt in the warmer season and spawns the winter generation between August and early October ; the winter gcneratiori grows for a few months but obviously growth ceases in winter. They grow again in spring and spawning takes place aftor May. Sizes at maturity differ markedly between the two generations. The average body length of adults of the winter generation is more than 1.5 times that of the summer one. Both generathiis die iifter spawning and hence the life-span is nine to ten months for the winter gcneration, whereas it is two and half to three months in thc aiinimer generation (Fig. 17). Yaeuda P t aZ. (1953) even estimate t,hat the life-spin of the latter generation to be only twentylive to fifty dnys. Sivortscn and Holthuis (1Ofit;) supposed that Acalzthephyra pclagica iii the North Atlaiitic attains wxiial maturity in the third year of its lift>. A siniilar result was obtiLiued for dcanthephyra qwdrispinosa in the northwestern Pacific; it attains inatiirity at two years of age and is supposed to live a$ least thrtse years (Aizawa. 1968). Table V shows estimates of tlic growth rates of thc six above-mentioned pelagic species from egg to rnittllrity. Under environmental conditions characterized by low temperatures and a poor supply of food. the growth rate of the lowcr meso- arid bathypelagic Shrimps must be much slower than that of thc q)ipebgic atid upper mcsopelagic species. Since there will be no seasonal variations in the chemical and physical environment of the tlcty SCU. their growth would be influenced mostly by the amount of food supplied from the upper layers, but no study has been made of this matt,c~ryet. The cficets of lower temperature regimes in the bathypclagic environment ran be defined as decreasing the growth rate. increasing longevity, and so producing organisms of larger size. and, in Inany cases, preventing attainment of sexual maturity (Mauchline. 1972).

TABLEV. AGE AT MATC-RITTASD AVERAGEGROWTHRATEOF PELAGIC SHRIXPS

Species ~.

.reu I

___ _

Sergestes sin1 ilis Sergia litcens d c e t a jayonicrcs winter generation sunimer generat ion Liicqer chacei dmnthephyra pelagica -4cotJhephyra qirdrtkpiriosa

--

off Oregon Suruga Bay Ariake Sea

Hawaiian waters Sorth Atlantic Sagnmi Bay

-4ge at maturity (nmnth)

Size at itiuturity (mm)

12 10-12

> 36 > 37

9-10 2.5-3

>22 > 12

0-7-0.8

> 24 >24

>8

>50 >56

Grou-th rate d uthwity (body length rnmlday) 0.10 Peare- and Forss, 1969 0.12 Omori, 1969a Ikematsu, 1953 0.08 0.15 0.32 0.09 0-07

Zirnmerman, 1973 Sivertsen and Holthuis, 1956 Aizawa, 1968

Mauchline ( 1972) a t t r m p t d t o est iin ttt thv longevity of bathypelagic crustiwrtins by corn perison with the growth rates of epipelagic species living in latitudes higher than 40°, and he stated that bathypelagic ruphausiids ttnd mysids live 2-7 tsimrx as long as epipelagic ones. If his eRtilTliLte is applied to t h e bnthypelagic: shrimps, then Hymenodoro *fronloZiam d [ I . ylucialis, which attuin IL b0d.v length of about 40-60 trim, rnny not, mature sexually until their second or third year of life wid lttrgc spec.imens are probtthly ti 8 ycurs old. My unpublished data from the wutms sirrroiinding Japiiii indicate that the life-span of the mesopelagic qwcies in the generit f h n a d a s , Sarge~tesand h‘ergia is one or two ywrs: Pasiphaea s‘p. mcttures at iLge of 1-5-2 years and lives for 2.5- 3 yews. I’robebly the spcc-icw of Oplophorus, Acanthephyra and h’gstulluxpis attain sexual ~nat~urity in the second, but mostly in the third, year of their lives and producc a sequence of broods within the next one or two years. (1

11. Dispersion and migration The ~ g g of s 8eryia lucens are generally spawned in the innermost part of Siiruga Bay, whcre the prc-spawning aggregation is found near t,he mouths of thc rivers. Recituse of the movement of the water mass, the larvae disperse seaward ilfter hatching, and the protozoea and zoen lttrvuc twe found more or lcss evenly distributed in the upper layers of the bay. Some of tliern itre ciwied to the open sea and are protmbly iinable t,o return to their birthplace. Maintenance of the larvae in thc coastal water worild be Iargdy accomplished by landward transport by flood tides, the intcrnul mixing of salt wedges, and the cddics ciinsed by jet strcams in thc estuaries. A t the same time, the semi-enrlosed coiuiterclockwise horizontal circulat.ion of water infiurnoed by tlie Kirroshio appears to affect the retention of Sergiu larvae iii this bay. There is certnin evidence to suggest that the stability and intensity of the circ!ulating current during the breeding season uct as irnportant factors determining the size of the shrimp population. The post-larvae tfevvlop fairly good locomotive powers mid gradiitllly niove landward. Adolcsccnts oc!cur mainly in the western part of the buy in autumn and whtw, und the adultn reenter the said rrstricted waters in the next spring to spawn (Fig. 18). The spawniiig of Acetes japonir.w ~ H take8 O place in the innerrno& part of Ariake Sect (Ikemtitsu. J953). The pmt-larvae move to deep water in the c.cvitmtl part in ltite aiitumn and stay there in winter. They cwnics I)iiclc inshore again iir the wrly spring on the tidal currents. On tlie othw hand, the bentJiic penaeicls Penaeus dwrrzrum Burkenroad and P.japowicus Bate spawn offshore. They migrate into brackish

Fro. 18. Schemetic ilhiat.mt,innof the distribution of various developmental stagex of Serqin Z U C P ~ S in Suruga Bay. Darhinnw uf dotted a m denotes mlat,iveabundance of animals.

water at thc post-larval stage arid move seaward again when they have matured sexudly (Idyll imd Sission, 19(i6; Kurata, 1971). Larvae of oceanic pelagic xhrinips, 11s nieatio~iecipreviously, live nearer the sttrfwc tliiin (lo thc adiilts, ttrd thc watcr layers occupied by different stages may be moving iit different rates und even in different directions. In order to aiiswer the questions about how far a larva can travel and whiit proportion of larvat. are lost through being carried into unsuitable onvironincnts, many more 81 udics art’ neccled on the behaviour of larvae at, various stages of tbvt4opmcwt kind on the movement of wnkw iniLnsw rit vctrious plwes arid tirncs. I am of the opinion that t?vm for spwies which show tt very wide geographicd distribution, reproduction iiricl replocwnrnt of it popiilation generally take place in tt restricted itrcti. Seasonal off’sliore-inshore movement which might be related to reproduction was observed in Sergestes similis off the Oregon coast. The largest inshore catches were made during winter, the largest offshorr catches were during summer (Pearcy and Forss, 1969).

VLIT. FOODRELAWONSHIPS A. Il’ood and feeding

(Yrcnerdly, dl~capodcrustticcans tire prcdators or omnivores, and c’nn utilizc ViLrioiIs k i d s of food. They may scavenge decomposing d c d ninteriiil in ritldition to taking living prey. G u t contents of pelagic shrimps Lire uwinlly wcll-macernt,rd cmtl mostly unidentifiable. This arnorphous nitLteriti1 appcarrt to consist primarily of crustacean fragrnents and matted aggregations of fil)rous and granular debrin. Somc: may httve originated from dig(vitrd phytoplankton. At any rate, this is not, ciitircly thc result of digestive prowsse8, but also a r i m from the decomposed nature of the material at the t i n w of its ingention. The recognizablc remains siiggcst that smtLII crustaceans, caluiioid copepods and euphausiids romprise the bulk of tlw diet, but frustulefl of dirttomn, k’orsminiferit, hooks of t:haotognaths aiitl fish scales are freqiiently present. There in also some indication of cimnibulism. We cannot ignore the fact that shrimps feed on organisms after they are in the net (Cham, 1940). This suggest8 that the cxamiriation of gut contents in the past) might httve Ird to some misunderstanding of their normal diet when the shrimps were collected in plankton nets. According to Jiidkiiis and Fleminger (1972) thc diversity of calanoid species froin the guts of Sergeetes sitnil& wax much greater in net, samples tlitlri in fish-caught specimens : 42 species were identified in the net samples, but only 7 were found in the fish samples. They

288

MAKO'l'0 OM081

thought t ti& the ~igI1ifi~iiIlt,la~ greater numbers of the euphausiids and chaetognaths i i i tht. gets from tlit, net saniples may be indicative of feeding JLfter ccy)ture. Nergiu Zucmu feeds niciinly 011 suoh copepods as CaZanus paci$cus Broclsky, Clnusocalanus arcii icoruis ( I h a ) and Euchueta marina (Prestandrea) living, roinmoidy, above 200 in depth in Suruga Bay. However, thc gut contents w r y somewhat seasonally. The guts are filled with the copepocls in spriiig when they are most abundant. Eucampin woclincus Ehrenbcrg, a neritic diatom which increases in the early spring, is found only in March. Chaetognaths and larvae of cuphausiids and decapod crustacecms are occasionally taken in summer and aut~umii. I~riistnlesof thc diatom Coscinodiacus spp. and fine mud, togetiiw with t~ hrgc proportion of' griLnular and fibrous debris, are present i n wiiiter; this suggests that the detritus may be an important part of the divt of 8. Zucens especially during the cold months when the shrimps occur near tho sea-floor (Omori, 196%). Guts of Sergestes sirnilis cwntain, hc~sictexmixtures of thc granular and fibrous debris, mainly ('ahit U ~ Y par.(ficm anti Melridin paci$ca Brodsky which are most ubundant and frequently occurring calanoid species inhabiting the uppermost 200-300 m i n the Ciilifornia Current region (Judkins ant1 F'lemingcr, 1972). These finding8 indicate that the upper mesopelagic shrimps fwd on living prey and decomposing dead material which are most common a t tho time they were caught, although small crustac~:ttnsare the maiii constituent of the food. With the exrcption of the early larval stages, most pelagic shrimps seem unlikely to speciciiizu in particular food items. However, the structure of their feeding appendciges suggests thiit the size range of the food of one Hpecies differs from t hat of anothcr. Tchindonova ( 1 969) noted a (*oridationbetween the form of the feeding appendages and sixe of the food items in the guts of variow shrimps, and stated that Sergtwtes sindis. h'et-gin jnpotiicuu and Hymenodora glacialis eat small prey whole, wliereau Umtheogen~aema(as G'ennadas) borealis, small speoime~isof Hymenodora glacialis and 11.frontalis grind their food. Henfro and Peitrcy (1 966) reported that Beryestes sirnilis can utilize food in a wide range of sizes, and swallows larger pieces, whereas thc mouthparts of Yasiphaea paci,fica are better adapted for manipulating relatively large prey than for capturing minute organisms, and thc food items are chopped into many pieces. ASergestes serrhtuclus, rSergia luc~lzsaiid S . prehensilis swallow food itcms and break them up in thc: guts; their guts are very muscular and have an efficient gmtric mill ensuring that large food items are properly reduced. On the other hand, 0plopkor.m grncilirostris nnd 0 . spinosua capture large prey like

T 1 i E liIOIA)(:Y

OF t’EI,A(:i(’ SIIRIMPX I N THE OCEAN

289

dectLpotl l;riistthct?iLnsund fish i d grind thrtn into small pieces in the mouthprts; the wall ofthe gut is thin, flexible und s1nootI1, and the gut cttn contain ii Itirge nniount of foot1 at sny onc time (Oinori, itnpublishcd). As t1esorit)cd in Scctioii 1V, t l u w tire severti1 rrports showing that the populiLtioii maxima o f c+oiigeiitbi*icb npeckw tend to occur a t different depths. A possible interpretation of this phenomenon is given by ‘I’chindo11oviL ( 1 959). Shtl suggests that the phenomenon reduces food compctition among species which liuvc similttr feeding appendages. Feedirig of adult Rhrimps rhangcs from a lower trophic level t o a higher oiic with increasing depth of the distribution. A number of Lucifer pemicillifer Hailsen were orice found in the coastal waters off Japtin with the hlue-green alga Trichodrsniium thiebautii Oomont ; they were holding, in many occusions, its colonies near the mouth (Omori, unpublished). As shown in Table \’I, the species such as Sergestes windis, Sivyitr IUCC‘IM t ~ n dPasipham pacifica, inhabiting the lowermost 100 111 ut night,, feed chiefly on herbivorous calanoid copepods and euphuuniids. Conversely, Acanthephyra purpurea, A. quadrispinosa and Syslellaspis tlebilis whirl1 live predotninantly below 150 m, take ostracode, d e c t p d s and such mesopelagic fish as Cyclothone spp. in addition to the copeyods. The shrimps almost certainly catch and swallow faecal pellets of the epipelihgic aninials before they break up. Diatom frustules i i i thr gut contents of the lower meso- and bathypelagic species might be transported through this process. The deeper-living omnivores tire probably biased towtirds a carnivorous diet because the particulate niittter avtdablc to them will only be the sinking dead bodics of orgtiiiisms, casts and id pellets ~ I U Hassociated bacteria. Curnivorous cqwpotfs, ostracwds, medrrstte and chaetognaths are the main constitueiits of thf*gut wnttsiits of hathypelagic species. Two procthxsrs of tlir feetling hiLve been observed in the postlarvae of Srr!yiic Iucens in the laboratory (Omori, 19718). When the shrimp is swiitiining forward, the third maxilliped and the first to third pereiopodn art‘usually stretched slightly forward on either side so that, with the lorig setue at, the fringes, they ran form a scoop-like net as a cittcliing device.. 111 the first prorrss. 811 A rtemiu nauplius which entered this d w i w :uid tmic4ied the setae was brought into a position where it could be seized by the second niaxillipeds. The mandibles then macertbtotl the prey m t i the food pawed to the mouth. Unless physical contact, with t t i c prey was matlc within this device, the encounter was unsut~rt~8sfirl.The second proc’ess is an active hunting of living prey. When t h r shrimp encounturod the prey a t a distance of about twice its body Icy$t, it suddrnly circ*ledaround the prey sevcral timcbs so

TABLE\-I. C'OUPOSITIOS OF GCT COXTESTS OF P E L A G I C S H R I X P S (Species are arranged roughly with depth distribution from shallow to deep layers)

Speciea

ilcefes chineiz&

A. eythrcrt-us

f'eima petrunkevitchi Sergia lweiis SergeakA similis S. sinailis by. urcticus

S. semiiiudrrs SergGt prelre ii.pil i s Puaiphuecc pcccijcu

P . rndidanirrtn Oplophorus ,ygmciliroatris 5). SpinOSU5

SysteUapL.9 dcbilbn Acunthephyrn qumiriapinosa A . p rpiweu Sergin j n p n i r w Bentheogeimentcr horenlts

H ynreir mlorci froil tnlis R y men miorn glrrc in1is

Phyaetocmia microphthulmu

Omori, unpublished

Le R e s e , 1970

Burkenroad, 1945 Omori. 1969a Tchindonova, 1959 Judkins and Flerninger, 1977 Omori. unpublished Omon, unpubli.;hed Omori. unpublished Renfro and Pearcy, 1966 Apollonio. 1969 Omori, unpublished Omon, unpublished Chace. 1940 Aizawa, 1968 Chace, 1940 Tchindonova. 1939 Tchmdonova, 1959 ; Aieaa a. 1968 Tchindonova, 1959 Tchmdunova. 1959 Tchindono\*a, 1959

‘FILE lIlOLO(IY OF I’LLAUIC SHRIMPS IN THE OCEAN

291

that the lwey W ~ brought R into the centre of it strong vortex caused by the body iilld widely opcm long nriterinal flagella. The prey was theti easily hcld by the sec>olidmitxillipcds. According to Zimmerman (1 973), ft*edingof Lucifer chrrcei wits often initiated only after a prey swtbrn rlowc to the vontrd anterior iir(ttt of the Lucifer’s body. A few titncs, liowcvcbr, it lunged II fctw millirnctres to catch thc prey. C:encrdly shrimps feod actively at night. The guts of Sergia Zucens are tilled with much more food at night t h m in daytime. This and the trend to wtird Icsa advanced digestion in night samples snggest that the fectding uotivit,y becomes highcst in the period from sunset to 3-4 hours twforci siinriw (Omori, 196!h). A similar result has beeii reported for Serg~stes siwiilix (Jndkine und Vleniinger, 1972). Apparently an individud i w i i r n i L 1 does riot fcetl 24 hour8 it day but has resting periods. It is not m in usual that 30 60%, of the guts of meso- and bathypelagic shrinii)s itre empty or almost rmpty. Seryestes similis and Acrtw jnyonicirrs dso have, occtisionully, many of the guts empty (60% or more). Although we lark knowledge of the digestive rate, the y iibk to live for long times without food in the deep shrimp n ~ btIsyors w Iierc p r q ‘ is scarce. A rehtioiiship between the feeding activity and the diurnal migration probably exists, but we have little data on feeding patterns in the spccius living below 500 m. Respiration of epipelagic euphausiids mid NerrJrsIrs . s k i ilia tends to he independent of hydrostatic pressure, but clccroc~scsgreatly with depth because of decreasing temperatures (‘real and (hrcy, 1!307; PetLrc*yand Small, 1908). On the contrary, rtwpiratioii of’ thr lower mesopelngic s p e h s such as &rgia 8pZpnden.r (ns S. crns8us), Oplophorus t+pinosuN, ilcanthephyra purpuren and 8y~teEla;upi~r dPhilis tq)pears to remain conatant throughout their depth rtingca ( N a p m , 1964 ;Teal, 197 1 ) (Fig. 19). In these species the decrease in rcrsl)irution wused by lower ternperaturca at depth is off-set by an iiicrrase due to higher Imssure. These contrasting results suggest that it, is to the itdviintsge of the lower meso- and bathypelagic shrimps to be uble to muiritnin their predatory activities throughout their range of’ migration, by day as well as night (Teal, 1971). Crirstacetin larvae are freqriently filter feeders, adolescents omnivores, while thc. adults may be more strictly carnivorous. The nauplius of Seryin Zmw. and probably of all penaeids and sergostide, does not feed but’ obtains its nourishment from the remainder of the yolk present in t h c body. The antennae and mandibles have no ventral setae for filteririp food from the water. The fist protozoeal stage has functional moiithparts I I feeds ~ by filtering suspended matter including phytoplariktm from the surrounding water. During the breeding

stwwn, t hr diat o n i ~Chnrtowros spp. (C. aflnis Cleve, C. decipiens ('lrvc, ( I . didywm Ehrcnberg, ctc.) tire extremcly abundant (freyuently more thiin 10" cdls/ni3), i d they repru:st:nt 60% or more in volume of the net ~tliyt,o~)laiikton in lint WP. In the laboratory. Seryia Zucens first stwted foeding on (Ihn~torerosr:Pruto,vporum Ostenfeld a t the first protozo(~idstibge and then tended gradually to be omnivorous after the zoeul stage when they titc Artemia nuriplii (Omori, 197 la). Zimmertiinn (1!)73) iiidic+tktedthat8 it, is possible t o grow Lucifer chacei from egg to adult without introducing any anirnal food. Undoubtedly, the pwiieids cuid swge~tids havv to feed on phytoplankton in certain

T-O -+-1

s1

pinriods of thv early lnrvrtl fitngcs, and presumably this behaviour relates t o t h o adult's vertical distribution which is shallower than that of' the otiritfs. The zoea larvae of carids, especially those of Oplophorue, IIynLsnod o ~ and u Syetellaspis, have very reduced mouthparts which are probably not functional. Presumably they feed entirely on the yolk in their thorax during the early stages, and after metamorphosis they soon adopt the feeding behaviour of the adults. Except for Zimmerman's work on Lucifer chncei, no studies have brttn done on the nutrition and metabolism of pelagic shrimps. Zirnmern i t i n ( I !)73) wicwssfully reared Lucifer from egg to aduit, and measured tho transformiition of energy from protozoes through to the adult using

TIIE IIIOLOUY O F PELAGIC S H R I M P S I N THE O(‘EAN

29.3

several phytoplankton species and Artewiia nauplii as food. The following are some of results obtained by his experiments. The mean feeding rate of the protozoeal-zoeal stages on DunaEiella tertiolecta Butcher was 805 cells/individual/h and the mean assimilation was 10.1 % of calories ingested. The feeding rate of adult was 4 850 cells/ individual/h with an assimilation of 7.7:/,. Individual adult Lucifer ingested about 42 Artcmia nnuplii pvr tliiv ; the mcan assimilation was 22% of Artemk calorirs ingrstrtl. Tho mean grow and net growth efficiencies of c:omhincd stagcs w(w I O.Z(%, nntl X I 1 % respectively. st;Lg(:s of Spryia ZUC~VM inge8totl On the other hiitltl, curly r)o~tt-l;lt.\~ill I!) to 7 0 Artemia nthuplii, al)l)roxirri;bt,cilyI :j 45%, of its own wctight, g per day (average I9 pg C/day), cintl gibilltd tho weight of 1 O. I [ ~ (:/day under laboratory conditions. A nrrrnbcr of adult specimens having their foreguts full of incompletely fragmented prey were kept in filtered seawater for observation of the digestive processes. The shrimps always retained the gut content,s €or 6 to 8 hours until defaecation (Omori, unpublished).

13. l’rerlators Species of the genera d c e f e s and Lucifer must play a significant

role as the food of fish and shrimps in the coastal waters. Although very little is known about the feeding habits of the post-larvae and juveniles of economically important fishes, the shrimps are no doubt the dominant components of their food in their nursery regions. Acetes and Lucifer are extremely important in the food web of the fauna of mangrove swamps in the Indo-west-Pacific. Hardenburg (1931) mentioned that a l l fish stomachs rxamined by him a t the mouth of Rokan River, Sumatra, wwc f i l l ~ lwith ,Sar:/a4te.u spp. As he reported that those ,Ser!/wfp.y w ( w fishcd c:omrricwiiilly in the area, no doubt they are Acetm spp. A c P ~ P r?r?ylhlrwu.9, .~ A . sa.rrulr~tux Krrayer and d. vulguris Hanscn arc t h o main food itoms of vitrious coastal fishes of the Singapore Straits such as the anchovy IJn,!/rauli.y dussumieri (Valenciennes),the silverside dtharina valenciennai (Hleekcr) and the lizardfish Sauridu gracilis (Quoy et Gaimard) during the period from December to March (Tham, 1950). OfTqhore in the 8outh China Sea Acetes are eaten by the mackerel ,%ombar sp. and the cephalopod Loligo sp. The local fishermen often locate the fishing ground of Loligo by the shoals of Acetes a t night (A. K . Tham, personal communication). According to Nataraj ( 1 ‘347) ,4c~tas arythraeus and A . serrulatus johni appear in large swarms in the coastal waters of south India from April to July and during these months are invariably found in the

294

MARO1'0 OMORl

stomach c~o~itents of the diffwcnt cdible shoal fishes. Occasionally they form tho food of sardines iuid mackercls. From June to September Acttes forms tho chief cliet of' the whitefish Lactarius sp. and the lisirtail l'richiurus YI). Aiiii1,ysis of stomach contents revcals that A. erythraew snd Lucifer ~ p p arc . ctiitcn respectively by 18 and 16 out of the 2%spccies of fish off' the Travancorc coast (Nath, 1966). The former species constitutes the major part of diet of the slenderscaled scad Salaroidps leptolppia (Cuvier), the golden scad Selar kalla (Cuvier) anti the pointed-finticd pike Sphyraenu mutipinnis Day from Novomber to Mnrch, whereas the latter species is a particularly importmt food item of such thretdfiri breiirns as Nemipterus furcosus (Valcnricnncu)and N. jnponicus (Bloch) during January and February. These two sergestids tire also the most common in the stomachs of the common sprat Dussumieria acuta Cuvier et Valenciennes, the Russell's scad Ilecupterus ruwelli (Ruppell) and the yellow-striped goatfish Upeneus vittutus (Forskkl). Le Reste (1970) reports the similar finding that A. erythwaeus and Lucifer sp. are major food items of larger penaeids and young shore fishes in Madagascar. Acetes juponicus in the Ariake Sea contributes the major part of the diet of the taper-tail anchovy Coilia mystud (Linnaeus) (Suyehiro, 1942). Ikematsu (1955, 1963) reports that many penaeids such as Metapenaeus joyneri (Miers)and M . monoceros (Fabricius)feed primarily on A. japonicun ulong with the mysid Neompis japonicu Nakazawa land copepotla. Imifer chucpi (as L .faroni) has been found to constitute one of thc most important foot1 organisms of the adult Hawaiian wchovy Nolephorus purpureirs Fowler (Hiatt, 1951). I'leuroncodes plnnipes is very important in the diet of the albacore TIwmrs (as GYemno) alnlungti (Ronnat,errc),the yellowfin tuna T.alhacares (Honnatcrre) (as Neolhunnus mncropterzcs) and the skipjack Katuuiuonus pdamiu (Linnacus) off Raja California (McHugh, 1952 ; Alvcrson, 1'363). According to Alvcrson ( 1 963), the stomach contents of the yellowfin tuna from the region to the west of Raja California are dominated by the Pkuroncodes: the average volumt: of the specir:fi contained in each yellowfin stomach is about 0.5 1 (78% of the total volume). Pleuroncodes monodon. constitutes the main diet of' the Chilean conger eel Genypterus mnculatus (Techudi), representing a 75% frequenry in the stomach (Henriquez and Bahamonde, 1964). The species has been found on one occasion in the mouth of Merluccius gayi guyi (Guichenot), a commercially important hake in Chile (Fagetti and Campodonico, 1971). The adult and pelagic Glymothea stages of Munidu gregnria have been known to be an important food of several cetacelttis including southern right) humpback and sei whales. In

udditioii, they &reeaten by tnaiig rookficrli and several species of sea1)irtlrr (Mat,tlit:ws, 1932). Secmicily, we consider the predtLtors of' mesopelagic shrimps. Kowka P I n2. ( I !)en) exarnincd t h stoniac~hcontents of various fishes (wight from t tic fishing grouiidx of Scrqirr Zucpn8 in SurugiL Bay, and fouiid A"~rgiain 22 out of the 44 species of' fiNh iind 3 out of the (i species of ctoyh;rlopotix. Fruqimicieg of t h o occiirence were 90% or more in the Jiq)aiiew Mi-luli chines Narpudon wicrochir Giinther, the

r

-IjJ diarkbllie Imdlightfish Diuphus coerulew (Klunzinger), the glandulous hcudlightti~hI). glnrhdulifer Gilbert, the bluebelly roughy Gephyrobrr,y.c japon irue (Ddderlein) antf the rabbitfish Yromethichthys proiriethpus (hvivr et Vtllrncirnnex, and the last species contained up to 26 individuals of Sprqiir in a stomach. The= dnta and the results obtained by Naktti ~t al. (i966) and Omori (1969a) suggest that the hoadlighttinh. pwticularly D. coeru1eu.s and D. glandulifer, are the most important predators. The influence. on the stock of S. lucens. of predation on the d u l t shrimps by the former fish and on the postlsrvuc and edolcsrrnts by the latter cannot be disregarded. Figure 20 shows t,he food web of the pelagic+community in Suruga Bay. 8.lucem

appr(%ntlypli~ysa marked rolo it1 trtmsf(wirig organic matter to large <18'I(' ZOllCS. wiirniiln i n t ht. nit'so- itnd I)i~t~hyl)(.I* Af,r@as &milis is voruc.ioiisly caten by fin and sci whales in the watcrs bounded by 5O"N nnd 40°N, mid 132"W and l43"W and also ITi7*W ttiid 174"W (Vig. 8J), wlicrc the d i r i t n p arc available in dense ~ w t t i ~ i~ni ~~ i thc i r siirtbw. 1 1 1 t h w trwo tireas dioto of' iLboiit SO./,, of fin whales t ~ i t t l 1 0 % of' sei whtsltts vonuiHt of N. similia (Omori et nl., 1076). 'I'li~~hrirnpst b w t1isfrik)irtrd thiindantly off the W~tnhiligtoiiand Oregon coirsts, kind prey(d II pon by albtlcore, rockfish and squids (€+rc.yra d nl., I9liD). According to Dr R. M. Luurv (personal communic*tittion).t hcy comprised 4 5 4 6 % of food of the albacore there in

the sitiiiniw of 1968. It, is noteworthy t h s t only the albacore, among irnporttmt tiinas of the genus Y'huni~usin the Pacific Ocean, feeds on siicli nitwqielagic shrimp as Srrgestrs sirnilin.. Presumably this is cnused by the fact thiLt only albacore have a feeding migration to the nort$ht.rntttmperat,c. ttnd subarctic regions. In this connection, the stoinwlis of the albacore caught in thc Hay of Biscay often contained lip to 187 individuals of Reuyrs/es nrcticus, a closely related species to S. s i n i i l i s . along with a snittll number of Gennudas eleguns, Sergia mbusfus. Pansiphaen op., Pnrapmiphae subatifrons, dcanthephyra p ~ l n g i ~ n( i L R A . mullispinu) i d Sgstellanspis deb& (Legendre, I 1140).

Thc rnaiii p m h t m s of nic+xqwI;igie shrinips may be rockfiHh such

‘rn ir

BTOLOQY oi‘ PELAGIC:SHRIMPS IN THE OCEAN

297

Sehnste.u ant1 Aebnntiucua, vitrioux niyotophids and cephalopods, but t,hrre i H v c ~ ylittlts inforrncttioii iLvailublr on the food of these fish. Muny pre(liLtors probably cat, t.ho 8hrirnps by accident in the midwater luyer ritther than by design, cutahing them along with more important food orgunisnis. Yauiphac?amul/identata along with two species of the genus Panrlalus comprised 9 to 27% by volume of food of the redfish Sehastes marinus (linnaeu.us)in the Gulf of St. Lawrence (Steele, 1957). According to Ptixton ( 1 987), who examined stomach contents of myctophids from California, of 139 specimens of Stenobruchius leucopsarw (Eigenmann and Eigenmunn), Lumpanyctus ritteri Gilbert, Ceratoscopelus townsendi (Eigenmann and Eigenmann) and Lampadena urophws Paxton, twenty had eaten sergestids. Some of other fish feeding on the shrimps are the New Zealund groper Polyprion oxygeneios (Bloch et Schneider) (as 1’. prognathus) on Oplophorus novaezeelandiae de Man (de Man, 1931), the anglemouth Gonostoma elongaturn Giinther on Acanthephym purpurea (Chace, 1940), Polyprion oxygeneios and the ling Genypterm blacodes (Bloch et Schneider) on Sergia potens Burkenroad (Yaldwyn, I957), Thunnus albacares on Sergia gardineri (Alverson, 1963) and Funchalia woodwardi Johnson (Penrith, 1963-cited by Dragovich, 1969), and the lancetfish Alepisaurus ferox Lowe on Sergia lucens (Kubota and Uyeno, 1970). Figueira (1957) reported the occurrence of Pnsiphaeci hplocrrca Chuco, P . multidentata, Oplophorm spinosus, Acanthephyra curtirostris, A . eximia, Ephyrina hoskyii Wood-Mason, Systellaspis crisiata ilnd 8.debilis together with two species of Heterocarpus from tho stoni;ichs of the scabbard fiHh Aphanopus carbo Lowe which were caught from about 600 to I 000 m depth on long lines by Madeiran fishermen. Luttr, Eupaaiphae gilesi m d Acantkphyra purpurea were also found from the stomiichs of the mme fish (PiHher und Ooldie, 1961 ; ]%her. and Kon, 1959). Mr 1’.Sasiiki gave me un opportunity to examine the stomtrcti contents of the pelagic srmorhead Pentaceroa richarhoni Stnitli whicuh were aolloctcd by RV “Kuiyo Maru” from the Milwaukee Seamounts. west of the Midway IsImdN, in I)ccember 1972. ConsideriLbk numbers of Sergestes artrmlus were found together with thc euphuusiid Thyllsanopoda monacanthn Ortmann and the myctophid Louwinn rnra (Liitken). The blue white dolphin Stenella caeruleoalba (Meyeii) preft*rably eats Hentheouennema borealis together with Pusiphnea sp. and Acccnthephya sp. in Sagami Bay, Japan (Miyrtzaki et al., 1973). Thew are interesting records showing that Pasiphaea longispinu W ~ L H found from the stomachs of the Emperor penguin ilptenodytes forsteri Gray anti the mow petrel Pagodrorna nivea (Forskr) in the antarctic region (Lciiz and Strunck, 1914; Hale, 1941). UR

298

MAKO‘I‘O OMOR1

Ix. (_’tTBMI(’AIA C:OnfPOSITION Prclimiiiary hiorlicmionl iuittlysce of some pelagic shrimps in the Izu rcgioii Iisvc besn c*arricdout, to chtrrminc the contents of total c*arboii,nitrogen, h y d r o p i allti i t ~ l i . All scimples bltt Acetes j f t p ~ n i c ~ wcre obtteincd in tht- it\lt11)>31>: thcy w c w f~ee.r,e-dried at - G o C and wc4ghrd. Inmcdiatcly prior to the biocheriiical malyses, each sample ~oritairiingt i t least three, but rnostJlv eight t o ten, individuals was thoroughly ground. The sndyses were carried out by the same method ILR dcwribetl previously for several zooplankton species (Omori, 1969b). To detcrniiw thr amount of total protein, the value of nitrogen obtniiicd wits tnultiplird by i t factor 6 - 2 5 The result is shown in Table V1I. Total cwt)on (*ontent varied from 40.20(, to 64.3% of the dry weight. Tht. nvwage valur obtuinccl for spccies was 47.3%. Three bitttiyp(~lu#io specictl, i.c. Brntheopnmemn borealis, J’arapasiphae sulcntifron,s i ~ n d I’hys~tocaris microphthalmu, showcd apparently highrr rnrlon wntent thttn the other shrimps. Total nitrogen content ranged betwecii 5.?y0iind I1.5%, with un average of 9.5%. A clear rliffereiicr: 11 ;is forintl in the protein content of the shrimps occuring in epipclirgic a n d upper rneuopchgic zoncs lts compared t o those of the btithypelagio zone. ‘I2 hc average protein contciit of six species including juveniles of the deeper forms which inhabit the upper 400 r n was 67*5y0, whereas that of three bi~thypebgicspecies was 39.3%. There was il tmdency for clccp-living forms to hitve a higher C/N ratio. The water coiitont of pclitgic shrimps ruiiged from 75 t o 85% approxirnutely i d iwh contcnt reprcscntcd from 4.4% of the dry weight for o c w i n i c . sproios BvntheogunnPma borwlis to 1.?.5%, for neritic form .4cetm jczponicu.?. Little i ~ i f ~ r ~ n i t t exists i o n on t h c b biodiernical composition of pelagic sliritiips. Jtityniont et ul. ( 1!W7. l!%Ij) hitvc analyseci thc fraction8 of protein, lipid, cwboliydratcb uiid L L R ~ of Cennadas propinpus (as 0.rluuicnrpus), rl cnniheph!/ra yurpurpu and wpecien of the genera Ir’uticlrtrlin.S c r p s t e s . A wnthrphyur arid S!/s!ellaspis. Their data suggefit 53-64?, protein, 1 - 3 Y o carbohydrate ltnd 15-24% ash in dry weight of the shrimps. Although their m h valiics arc’ relatively higher than the present one, the iippcr range is siiniliir. Table V I I l shows lipid contrnt of sonic pelagic shrimps that have so fiir beeii iLiialyscd. Apiirt from Hiwfheoqmncmaborealis, Petalidium foliacpu)ti, StjrgeutPs sirnilis, h y i a hisu1catu.v (N’ood-Miison) and S . h c e n s which were obtaiard in tlic North Pacific, all sarnplw were taken i i i tho North AtliLntiv ( h t ~ n .I n most cases, thc lipid contents were ex-presscd as percxwtugr. of wet w i g h t . They wtm nonvrrted to

Sunrpling

drrfe --

Bentheogennernct borccllrx Gennnrlns p r t 7 u s (jm-.) Sergestes sijn ilin Sergia lucens (jut-.) S. lucens S . prehetleilis S. japonic~rs(juv.) S . japo)hicus Acetea j n p n i c u s Lucifer sp. (juv.) P a r a p a i p h e sztlcnt~ro~zs Opkphmzcs spirzoszts (juv.) d c u ~ ~ l h e p h yq?mdrispinoscz m A . qtrccdrispinosn Ph ysetocnrk rni
---

-

SOV.1972

dppro.rin!tite depth of sampling ( t r ? ) 800-1 100

Sox-. 1 9 7 2 2 0 0 -

Sov. 1972 Soy. 1979 U c t . 1970 Oct. 1972 X u 1 SOY. 1972 .log. 1972 Srpt. 1967 S O .2 Xnv. 1972 S O .1 7 So\-. 1972 Suv. 1972

400

600- 900 0- 100 50- 100 100- 300 200- 400 800-1 100 0- 50 0- 100 800-1 100 400- 800 400- 600 400- 600 800-1 100

-4 rernge d r y wt! iad. ( m g )

H

C'

S

Protein

to0 dry weight)

-4sh

C' S (ratio)

S~RIXPS TABLEVIII. LIPIDOF PELAGIC ,Species Bentheogennema boreal is Gennadaa ytcr~w C . valens Funchrrlia woodrcardi Sergeetes arctieucr atlanticus S . corniculum S . &milk Sergia bisulcatus s.lzcGens S . robustus Petalidium foliacezci n Oplophorzcs spinosua Acanthephyra acanth itelson i s A . eximia A . pelagica

s.

A . propinquw A . purpurea

8.ptellaspis dehilis

Sampling date Apr. 1956 Xpr.-June 1955 Jan.-Mar. 1968 N a y 1955 July 1955 SOT.1954 .Jan.-Mar. 1968 Xpr. 1956 Apr. 1956 Apr. 1969 July 1955 Apr. 1956 Jan.-Mar. 1968 Jan-Mar. 1968 Oct. 1970 Oct. 1970 Apr. 1958 No\.. 1957 Sept. 1964 Jan.-Mar. 1968 Scpt. 1964 Oct. 1970 Sept. 1955 Nov. 1954 No\-. 1955 dan.-Mrtr. 1968 Oct. 1970

Tohl lipid

("b dry wt)

62.4 17.1 12.0 57.2 10.9 17.7 9.2 16.1

27.0 7.0 31.2 72.8 234 19.6, 48.7 12.0 16.1-27-0 5.7

18.2-20.8 15.0 11.2 12.0 8.8 9-4-26-5 2.2 9.8-13.0 19.6-28.4 7.3-19'8

Authority Fisher et al.. 1957 Fisher et al., 1957 Culkin a n d ,Morris. 1969 Fisher et al., 195i Fisher et al., 1957 Fisher et al., 1957 Culkin and Morris, 1969 Fisher et al., 1957 Fisher et al., 1957 Omori. unpublished Fisher et al.? 1987 Fisher et al., 1957 Culkin and Morris, 1969 Culkin and Morris, 1965 Morris, 1972 Morris: 1972 Fisher. 1962 Fisher, 1964 Raymont et al., 1967 Culkin and Morris, 1969 Kayinont et al., 1967 Morris, 1972 Fisher, 1962 Fisher, 1962 Fisher, 1962 Culkin and Morris, 1969 Morris, 1972

'IWE 13101.OOY OC PELA(I1C HHRlMYS IN THE OCEAN

301

prccntage o f dry weight by taking dry weight equivalent of the shrimp biomass, 5.2. On the wliole, lipid appears to be more variable than protein; i t vwios frotn %2y0 of dr,y weight for Amnthephyra purpuren to 72.8 yofor Pattclidiurn folimcuni . 1tshus been known for many species of copepods and euphnusiids th;Lt, in general the lipid contents of the mimills living i i i higher ltititiicles are larger than those of animals living in wrhtor of higher tcbmperaturcb, and that in any one sea area there are scilsotiirl VarititionrJ in thc anioiirit of lipid, as well as protein, carbon and nitropn, present in w~imals,which appoar to be related to the b r d i n g and growth of those animals. Differences in the lipid content between sexes are also obvious in adults. However, the data on shrimps ere apparently too small for discussion of these problems. The i n d i v i d d variations are considerable indeed. Fisher (1962) suggested that the percentage of lipid present in Amnthephyra perk& (LLH A . hueckeli) and A . purpurea tended to increase with the size of the rtiiirnal. IIIacltlitioa, the values in Table VIII indicate that deep-living species have relatively highor lipid contents than the shallow-living ones. This in formation may indicate that lipid of the deep-living species in primsrily a reserve energy store for the developing embryos and larviw and secondarily an aid to buoyancy, but this must be tmvpted with rescww.tion until fiirther analyses are available. Imvis ( 1967) studied the ftLtty aoid composition of a number' of fish and ~riista(~eans frotri various depths and found that the percwitiigcs of' medium chain saturated and long chain polyunsaturated : i d s decrecisedwith increasing depth, while oleic wid (18: 1) increased. The highest level of the oleic acid was determined in the bathypelagic shrimp A cnnthephyrn curtirostris, being 72%, and 77% of the total fatty avitls. 111this connection, the proportion of oleic acid in ( f e v ~ n a h s v n l ~ a a ,SPrgmtes corniculum anti Acanthephyra purpurea constit ufed 23- 28o/b, whercas in Oplophorue ,spirwsus, ,4 wnthephyra acanthitebonis and Spkllaspis dehili,p it amouiited to over 37% of the total fatty wid8 ((Ailkin a i d Morris, 1969). J,ewis statcxi that the high proportions of the 18: 1 acid are almost certainly due to the presence of large nmounts of wax wtt:rs. In h c t . it has been found by several workers that the occurrence of wax (.steta in the lipid of marine animals varies considerably among ciit€'erent species living in different depths and localities. The results of their detcraiinirtions suggest that the wax esters are laid down by the tuiitnuls living in tweas of low food density, where energy conservation is iniportmt. as energy reserves and partly to achieve a more neutral buoytliiq~(Ncvenzcl et aE., 1969; Nevenzel, 1970; Lee et d., 1971). A t ti subt8ropiculstation Lee et al. (1971) showed the wax enkrs were a

ininor piwt, of t h tottrl lipid i l l l ( l triglyccrides were t h c b niitjor class of lipid in many cwpcpods iiiliubiting t h v upper 325 t n , whereas the wax esters w(!rv i he tniLin lipid constitileiit, arid triglycerides were a ininor lipid cwniponrnt for t i l l c.oppods esainined from depths below 625 m. The 326-fJdh ni tlepth intcrvd t~ppeurcd to be a transition zone. A Hitnilar tcwclcwcy was oh-rvetl by Morris (1 972) in the analysis of lipid of ot Iicr oc(~i~tlic crustiLwirnH including a few shrimps taken from differcwt depths in the North Atlantic and western Mediterranean. According t o him, w a x chstcrs were present us only a sinall fraction .:(. 20% t otcrl lipid) in t h species tnigrating in t,he upper 600-700 m (Acnntiqhyra purpurea mid Systelluspz’s deehilis) or living on the seaerhsifw A . Milnc Edwitrds and H. grimnldii A. Milne floor (Ilefr~rocnvpus Acanthephyra pelayicn living below Etlwixrils et Uoiivier). Convc~~e’ly, WO n i coi1tiiid :L much higher percentage of wax esters (44-65% total lipid). Wax estcrs and tryglyc*critles have different densities and comprcssibilities reliLtive t o thittj of‘ seawater. According t o Alexander (2!)72) the ncritrnl huoyimvy of fish for which volurne/mass = 50 cni3kg-1 run he achieved i).\r means of wax esters if they constitute about 20% of tho t o t d body weight. Some of the deep-living pelagic shrimp, whose volnme/mass is near to 50 cm3kg-l, appear to have wax esters very close to this aniount. Accumulation of wax esters by ~ n c ~ ~ p ~ l im k gdi c1)ntliyycliigioshritnps is accepted as an evolutionary aclirptation in conncxion wit ti vertical migr2Ltion and buoyancy regulation, rillied to soin(*fitctors such iLK t~hcreduction in cixrltpace calcification. l)cntjou r’f al. (unpublished cited by I)enton, 1971) Hhowcd the provision of additionid bltoyitncy hy t h r acrumulation of large amounts of timmoniurn ions in cwtuin ocwnic crustaceans. ~ rneasiir(vi in sonic shrimps (Fisher rt ul., 1957 ; Vitamin A I i i bccii Fir;rhrr snd Kon. l!k%). The results in ‘l’able IX show that, except for Bpnthcoyrti tictiin ( i t s C:Pnnndn.u) borrdis. d l sjwcics annlysed contained tht* vitttmin. l‘hrsc spwies tcntlrtl to bca richer in vitarnin A thttn the t)clithic iLIi(1 littord forms so tiir tmdysed. idthoiigh the concentrution wirs r ~ l z ~ t i lower v ~ l ~t,hitli t litit of’ spec-irrj of’ euphausijds i n which the Itwan c~oiicr.ritratioiisof 3 I sl)ccicbs rang(’ from 0.15 pg/g wet weight in Thyttampotin peciitrriia Ortmiinii to 18.3 pglg in Thysanoessa gregaria Sews (IWIcbr imd Kon, 1 $15!1). ‘f’hc> rc1atk)nxhip between the vitamin concentrution of shrini 1)s irnd t,hc taxonomic affinities is not definite, but, scrgrstids i w l (v~ridsiLI)I)(’jbr to contain larger amounts than pen srids. Vitamin A is not evenly distributed throughout the tissue of euphatisiids i i i i ( l dtx(*iLi)odcrirstacwns. I n tlip formclr animals tnost of

vitamin A i s locritd in the eyes (Fidier rt d., 1955), but the distribution viwies in thr 1aLt)tcr. A re-examiniition of t,hodata presented in Table I X suggests that taliere is a tmdency for upper nicmpehtgic shrimps to htkve greutcr cwiiccntnit8ionof vitamin A i i i the ryes, while the vitamin is more confind to tlir bodicv i i i lowczr i n t w - anti batjhypelngicspecies. Mauchline und Fidier ( 19fio) siinitntwizrd t tic oc*uurrenceof vitamin A and rc*lnttd sub~titnec~s in vtlrious xpe(+n of tho Euphuusiacea and other marinc or.gt:tctiisms. AH thqv suggcstcd from the examination of the modes of lifc of mysitla, cup1~;tusiid~ arid decapod crustacbeans with

Species -

-

Rsntheogen)rr,nrii hormlis (:ennadm pawtiR Punchalia iooorlruisnli B e r p t e a arctirux rS. ntlantictix AS. sitnilis Serg ia 1i d c a t 118

s. TOtnMtU8

I’chlidiiim foliace t i ttb Litcifeer typus Acanthephyra citcrJlatrr A . curtiroatria A . prpurea H ymenodora fro ti tulix Parapandalrru rickttrdi

Vitamin A

w. . __ __

(P9h

0 0.17 0.097 0.31 0.74

3.0 2.2 0.4

2.0

25.0 1.7 2.1 5. 1 2.1 8.0

.

Main locality .

-

__

eye body eYQ eye eye body body body body

-

body body body

--

rich storm of vitamin A and with tk considerablr fraction of it in the eyw, the? present plienomonon iippeim to indicate that the visual sense is tnori! important to IAilgic shrimps in shallower waters than to those living in great depths or to benthic and littoral decapod crustaceans where chcinical i t l i d titctiie senses may be of increasing importance. Animals crmnot synthesize carotcmids but alter alimentary cwotenoids by oxidntiori c:tcnd storc the rraultunt product. The concentrations of curotciioicl pigrncntn rimgc? from 12 to 330 pg/g wet weight in t h c x pclugic shrimps so far tlntllysed (Table X). In the fish culturc farinx of Japan. thousands of tons of Buphausia paciJ;ca are fed to the red sea bream Chrysophrp major Temminck et Schlegel and

304

MAUOTO DMORI

sulmon to prcvent discoloirrution of the fish body. Catches of Ezcphausia from the coast of Miyagi Prefcctui*e amount to 2 000-8 000 tons t i yew. E . pncijioa, rilthoirgh showing considerable individual variiition, contains carohnoid pigments on an average 118 pg/g wet weight, of which 21 pg/g i R astaxanthin and its esters (Kayama and Omori, unpublished). According to Fisher et al. (1957), carotenoids in pcbnaeids include astaxanthin arid its esters, carotenes and xanthophylls, but only astaxanthin or its esters with occasional traces of xibnthophylls are found in sergestids. Our preliminary analyses by mc.tlns of thin-layer chromatography indicated that some species of PI(IMRNT (:ONCENTRATION TARIA: X. CAROTKNOII) I'E LAOlC

s HHIMPS

AND

ASTAXANTHIN OF

Authority 30

fi4 I !!O

2!) 37 I P O

4ti 150

I:! !I(; 84 1 I:!

234

25 I50 330

i i ii

t -I

t

43 83

' I

1

-

C'irhtv el

ciE.,

__ 1957

} I
the pelagic. slirirnps appear to contain apprwiable quantities of astexanthin and its esters, nlthough their proportion to the total carotenoids was smdlcr than that asmrned previously. Study of astaxanthin in such aggregating sergestids as Acolea and Sergestes and experimental me of the dwirnps as feed for cultured fiah may bring encouraging I'CslJlti3.

x. ~MPORTANCKOF I-'ELAC4IC SHRIMPS AS FOOD RESOURCES The use of plankton and micronekton for animal and human consuniption has been proposed by several ecientists. At present the following pelagic shrimps are fished cornmcrcially and oaten by the peoples of Asia and eastern Africa from Mozambique northward:

THE llIOl.OOY O F PEIA(4JC SHRIMPS IN THE O(!EAN

305

lurens, ArPtea chivwnsi~,A . rrythmeus, A . indicus H. Millie F:dwarc-ls, A . j p m i c u . s , A . wrrulatucv, A . sihogae, A . vulgnri.9 and €’n,sipha(~asp. All w e distributd in vnst swtrnis in inshore or estuarine wiiters. Holthius t t d HoHiL ( 1965) not(. that FunchnZin woodt/’ardi is exploited off the coiasts of‘ Port ugnl, Spiliii and South Africa. The c*ontribrition of the spx*it1s of Bcetes to the local fisheries is grrat. Although thc fishery s! iLtistics arc very inadequate, bxause Acrtre is moatly ronsumecl locdly, it is supposed that the annual mtvh of Acrtes spp. from Korw, China, Japan, Tuiwaii, Philippines, Vic.t.nam,t hinbotlia, Thailand, I{urrn;t, Mihyai;t, Singapore, Indoiiesitt and India niay cxceed 170 000 tons ;Lnd constit’ute about 25% of the annitril wtch of slirimps in thc Lndo-west-Pacific!region (473600 tons in J 970*) itnd l5(% of thtit in t h e world (930 000 tons in 1970, FAO, 1!)71). Catah records of Acetes m u s t be conaidered a~ minimal because reliable statistics are only available for t i few of the larger markets. Furthermore, Acetes apparently exists in potentially exploitable quantities in certain areas but is not fished due t o the richness of other fishery resotirces and the small size of the local market. tAcete.9 is mainly tished with various kinds of push nets and fixed bag nets set new t h e shore againat the flow of the tide. Ths material is dried or fermented for food in various ways and is esteemed for its taste and nourishment. A paste prepared from the salted Acetes is known ti^ “ Hlitchan ” in the MtifIiL.v I’eninsula and “ Gapi ” in ThiLiland. Acetes r i k w r s i s i H one of the rnost irn portalit nittrine resources in the Nortjh Chin;i. The amount of‘ clutch i i i the Gulf of Po Hai is tremelidous, amounting to 60 000- 70 000 torin a year (Liu, 1956). For a very long time (Ihinrse cant1 Koreans have finhed A. chineneis and A. japonicits along the coast of 1 he Yellow Sea (Yoshida, 1941, 1949). The annual landing attains about 6 000 toils in China (Liu, 1966) and it reaches 5 000 1 0 000 tons in South Korea (K. I. Yoo, personal coniinunicution). i n .Japan the fiqhing has been carried out for a long tinis in tho Ariake Sea (August to October), the Seto Inland Sea (April, May, S2ptember to November) and in Toyama Hay (March to May). Avcruge laiidings total about 1 600 tons in the Ariake Sea, although there are considerable fluctuations annually (Ikematsu, 1963). There is i t fishery for A. chinensiv und A . erythruezcs in Taiwan; tho catch amounts t o about 1 000 tons a year. Acetes spp. are fished along the whole cowts of Thailand. Recent annual catch reacheu 0 000- 19 000 tons, and i t constitutes about 13-22:/, of the total catch of marine shrimps in Thailand. The occurrence of six species of Acetes A’rr&z

* Cetahoe do not include the planktonic form.

306

MAKOTO O M O M

is reported from the waters of' t8he Malay Peninsula and Singapore (Pathansiili, lWi6). The amount, of their cat)ch in the West' Malaysia attirineci fi 700 tons in 1971; dmnt 12% of the total shrimp catch there. hi Penang, Miiliiysia, the fishing of Acetes continues throughout the year, tinct tho catch is highest from May to September. Conversely. according to Tharn (1 950, I955), the catch is nearly restricted during the northeast nionsoon (December to March) off Singapore. Acetes rrythraeus, A . japonicus (as A . dispw), A . serrulatus and A . vulgaris are found, anti during the southwest monsoon they appear only spordiciilly in catches of the fish t'raps which are set farther out to sea. Aceles i?uiiau.u is caught commercially along the Maharashtra comt, western North Indin, throughout the year, but the best landings arc obti~iiietifrom December to Monh (Kunju, 1967). These data, and the report by ,Jones (1967), suggest that the annual landing of Acctps attaius 9 000-1 0 000 tons and constitutes about 1I-] 776 of the total crustacean ciitch off the Indian coast. A . erythraeus and A . ser.rulatus two important in the fishery along the Madras and Kerala coast, (Joncs. 1!)67). 111 general, the fishing of Acetes spp. w i characterized by a fishing season rcstricted to it few months of the year in many localities and by catches wliioh fluctuate greatly year by year. Tnsufficient explanation has bwn given for these phenomena. Ikematsu (1957) suggested that the tlnnual yield of A . japonic?c,sseemed to be correlated with the air tcmpivatJiirein .June, the heaviest spawning season, and also with the catch of fish uaici crustaceans which feed on Acetes. Jn the tropical regions, there cippeured to exist some close relationships between the wind direction and the occurrence of the species in neritic waters. A fishery for Sergia lucenv has becw conducted in Suruga Hay since 1894. Fishing is carried out by haul nets at night when the shrimps come up into shallow water. The net is t)owcdby two vessels, 15 to 20 times a night. and at presrnt 120 vessels are engaged in this fishery. The nurnbcr of fishing days in recent years is about 50 to 80 dayti per year. Tho ttnnual catch of this shrimp totals 3 800 to 7 COO tons (more than 3 000 000 US dollars i n landed value), and it constitutes about lOcy0 of tlx ttnnual catch of (111 shrimps in Japan. The greater part of the catrh is sold as dried shrimp. Considering the size of the catch from this small bay, this fishery is one of the most productive resoiirces in the K~iroshioregion (Omori et ul., 1973). As described previously, the temperature during the early breeding season has a great influence on the fluctuation in the abundance of A'. lucens. Warm years bring good catchcs m d cold years poor catches. Omori (1969a) stated that poor fishing years appear every 9 to 10 years, indicating that there is a

THE BTO1,OOY Oh‘ PEIA(*IC SHRIMPS IN THE OCEAN

307

close relationship between the life of the shrimps and periodical fluctuntioiis of the Kuroshio Current. Pasiphaea, R I ) . is exploited in I’oyama Bay, the Sea of Japan, from April to November from depths of 50-200 m on the steep slope at the edge of canyons. The CittchCs tbmount to 200-500 tons a year recently arid they are often cwnsuiiied as a substitute for Bergia lucens. Today, Heveriil countries arc. attcvnpting the exploitation of the swperba. A t present, great resources of the Antarotic 10.111 ~‘zcphcczcsiu howovcr, thew tire two nitlin diffioultieu i n its utilization. One is the techniqw of the fishing, and another is the technique for processing it into food. So far as the Japanese investigations are concerned, the fishing techniqrio htis not been sufiiciently developed to meet the economic ciumand. We have to find out more about the basic biology of the sp:ies, particnlarly its mobility and swarming behaviour. Mtkuchline mid Ii’isher’s (1069) comprchensive study of euphtlusiids reveccled a life hintory similar in many aspects to that of sergestids. The modi fictktiort and improvement of the harvesting method of Bergia 1ucrrLq mug solve the technical problems of the euphausiid fishery. The incat of Euphazcsia is very soluble in water at higher temperatures, and ifs flavour, pit,rticularly that of the adolescents, is no better than thaC of the decapod shrimps. It is probably difficult to serve Ewphaz~fsiu for human consumption as u similar type of product to 8ergia and Aceteu. Certainly Acetea forms the inujor sourct! of protein for some of the local peoples in the Indo-west-Pacific. Biologictcl studies of the species of AcetPa sliould be carried out more extensively. Compared with the numerous workars studying the cwpht~iisiitis,the number of RcientiRtH interested in Aceks is too few. A t the Name time more attention munt be paid to the potential of pelagic shrimps as a comtnercial fishery resource. The ritilization of shrimps living u t a depth of 300 m or more a t night crtnnot be expected, tts vast exploitable swarms have not been discovered. However, the increase in havic information on the biology m d ecology of pelagic shrimps will lead not only to the improvement of the present fisheries but also to the finding of unexploited stocks. Suitilble fisliiiig grounds may be found and someday they will contribute to the world fishrry. Them is ti possibility of developing a fishery for the enormous stock of ASergesfrs~imilz‘ain the northeastern Pacific (Omori et nl., 1972). PreliIninary estimates indicate that the amount of these shrimps eaten l)y fin and wi whtiles in the southern ( h l f of Alaska reaches about 140 000 tons in t h six rnont’hnof the sojourn of the wtialcs in that xea

308

MAKO‘I’O OMOR1

(Omori. unpublishrd). The st;Liidiiig stwk of S . sirnilis Reems t o be gre;Lt, tclso o n t h e stw1) s l o p of thc wnyons off the west coast of the United Stittm. The potmitiid stocks of Nergia prehensilis off Japan and of S e r f p t r s nrctiws in the northern North Atlantic deserve to be

explored.

I n Chile the fishery of “ langostino ”, which includes two galatheid ~pc*cics,I!c.rvinrurda johni I’ortw aiitl PlPuroncodes monodon, reaches itbout I 0 000 toris yearly. lmighurst ( 1 968) postulated that the ti nexp I o ited p()piI luti on of I’leu~on codos plaaipes, which occurs in vast pelagic swiirtns as post-litrvite or adolescents a t the southern end of the Califoroia (:urrent and in the Gulf of California, could produce similar or gretbter yields. He states it is possible that a demersal fishery for this specie-s will be developed soon, and it is also possible that the of the prlagic phase, though this finhing mu.y indude ~xploit~;~tion wenis less iirwticviblc.

XI. SUMMARY 1. Present knowledge of the biology and ecology of pelagic shrimps is summarized using all available literature and our data. 2. The ~iumborof species which pass their permanent life in the pelagic phase is less than 210, and they belong t o the Natantia Macrura. Most, of t,liescx itre incl utled in the sit bfamilies Aristeinae and Sergestinae of thc wotion I’ciiit&lca 01’ t,he fiimilies Yasiphucidne, Oplophoridae itnd 1’;iiidi~licl;~r of the section Chkleil. :j. ‘l’hc geniis &-gustes s. 1 . is divided into two genera Rergestes and Serfyin. 8erqPste.s is distinguished by the semitransparent body and the prrsencr of specialized luminescent modifications of the gastrohepatic g11-m~(the organs of PestiL). Nergia includes both half-red and all-red species, but in many oases with dermd photophores. 4. The members of thc genera rlcetes, Yeisos and Lucifer itre pelagic shrimps inhabiting inshore or ncritic waters. A few species of the pentw k’unchrrlia, Se~geslex.S ~ r p i aand PasiphaPa also occur on shelf watrr on occasion. Offshore or occaiiic inhabitants are represented by the genera Uenthec?clPri?LPitI(i,G‘ennadas, h”%rgextes, b’erqia, Petalidium , Oplophorm, A rant hrphyra, Hyrnen,odorn, S‘ystellnspi8 and l’arapnndulus. 5. Pelagic. shrimps are irl~nosti~bwiiti n the polar regions. The famid divcwity incwmses from t h siib-polar regions t o the tropical regions, i i r i d rich ocrurrenoc of spcoics is seen in the temperate, subtropical and tropicd regioris. The oc(~anic,I)athypelagiu specie6 have wide geogrwphic: distributions, ivhereils t,hc neritic, epipelagic qxeciee

309

THE IIIOLOQY OF PELAGIC SHRIMPS IN THE OCEAN

are frequently restricted to one ocean, or even to one particular area of water off a single coast of one ocean. 0. The body lengths of pelagic shrimps range from 10 to 100 mm, although a few species grow up to 130-180 mm. The epipelagic and upper mesopelagic species are, tmnspcwent or semitransparent with orange or red c:hromat,~irhor.('K Imt all s p c i w living in tho uppermost 600-700 m depth by tl;iy h;ive iL more or less uniform pigmentation that varies from deep-red to scarlet. Special adaptations for the pelagic existence are observed in Revera1 species. Many shrimps possess various types of luminescent organs and are capable of luminous secretion. 7. Pelagic shrimps are good swimmers, and their distribution is usually uneven both vertically and horizontally. Unless the distributional and biological characteristics of the individual species are known, an accurate quantitative analysis of shrimp populations is difficult. 8. The shrimp biomass is large in inshore waters and localities over the continental slope. It decreases with increasing distance from the coast. The biomass is particularly great in water where the bottom slopes steeply away close to the shore and strong upwelling is frequently observed. The role of shrimps in the zooplankton community is considerable in subtropical and tropical regions. Shrimps generally form about 10% of the total zooplankton biomass and of 15-25% of the micronekton biomass in the uppw 1 000-m stratum ; on weight basis they arc comparable to t h e euphausiids and the fkh. 9. Pelagic shrimps are distributed from the surface to at least 4 000-6 000 m depth, but the distribution is concentrated in the depths where the food supply is greatest. They form a comparatively thin layer in shallower depths in poorly productive areas, whereas they occur in much thicker layers in the productive areas. The shrimp biomass attains the maximum in 1 000-3 000 m depths in the subarctic region of the North Pacific. The largest concentration of shrimp ix seen at 200-500 m in the areas between 30'N and lO"N,whereas in the equatorial region the role of shrimps in the 1 000-2 000 m appears to be the greatest. 10. Besides the food supply, the vertical distribution of xhrimps is principally modified by light penetration and temperaturc. 11. There is a tendency for the population maxima of congeneric species to occur at different depths at one locality. 12. Diurnal vertical migration seems to occur in all epi- and mesopelagic shrimps. The amplitude of migration in the majority of A.M.B.-12

II

mesopc~lagiospecicw rilnges bctwcwi I00 and 400 m. Bathypelagic , rindcrgo a lirnitecl, upward migration. slirinips I t ~ c kor 13. Epj- i L t > ( J mesopelitgia shrirrips are grouped according to their vcrtiorii iiiigrtrtion into five groups. At night the species of the deeper gt-oiip occul)y to t~ grcvrt, extont the depth horizon vacated by the upwt~rdmigrcitioii of the shidlow group. Two groups are recognized in btttli~~pt~liigic: specics. On the whole, the vertical distribution of Pcniteitlett is shtdlower than thut, of Ctwidea, and Sergestidlte are most intimiLtely wsociated with tlir upper layer. 14. l’hc slwinip biomass usrially becomes minirnum between 350 mid 800 r i i itt night. Tli~violaj,crs ugrcc with a dqjth of fittlnd transition from tlm lower iii(w)- to btil hyIwletgic species i L t night und from the half-nd to all-rod speciw by day. J 6. The dillrnd vertical migrittion of shrimps in rieritic watcm is modificd to itohieve IendwcLrd transport by means of tidal currents. 1ti. There iLre t h e types of ontogenetic migrations of the different groups of‘ sproies. Usually, 1arv;re of pelagic shrimps occur at lesser depths tli:in the ctdiilt. Hatching of some meso- and bathypelagic species ttkkes plwe sl)ove their ordinary hitbitationd depth so that the larvae rise rmcl o w u r in the euphotic: ZOJW or layers immediately adjacent to it whcrc thrrc is a rirh supply of food, but the juveniles and adolescents move dcrper. Other spcies are nt’ver, ; k t any stage of their life, present in surftice or subsurface waters. 17. Srrgestids itre often tLsso(4iLtcd with the sonic scattering layer. SerrJinZwen,s rnigrutes verticitlly with a maximum speed of 1 a 8 m/min, ttnd its swtwtris iq)parently ciLiise i~ sonic scattering layer in Suruga Htty. 18. The niorpliological variation of Iiiminescent organs with depth distribution, and the significmcr of thr: biolumineacencc tire diwuwcd. ‘l’ha xpcvics of the genus A‘rvyoxtvu hilvr tho ability to rotate the orgnnn of I’estiL 80 tliitt thc. illumination is ~ I ~ \ v ; Lpointecl ~s tlownward r q p r d lrsa of the oricwttition of the iinimid’H hotly. 1 !). The formation of vast ahouls is c.harac*teristic;of filter-fec:dr~sor potcwtiirl tilter-feedrrs. The function of shoaling by the larvae a n d juveniles o f ~ ~ l u gslirinips ic seeiris likely to be to help control their population ilntl ta niuintiiin p i t i o n within their habitat zone. The size riud popiiliLtioii cicnsity of the shoals change depending upon the stage O ~ K I V Mt 11. 1’113-spitwningilggrcption, probably relating to physiological cllinligcs wit liin t Iic species tht*nisc*lvcs,occurs in Sergia and Acetes. Thr popiiliLtioii drrrsith of t lie oceanic shrimps in the swarms are low (mipared with thosc of sornc of the euphausiids. Shoctling is also niodifird by illumination and temperature.

THE I310IAO(?YO F J’EI,AQT(‘ SHRlMP8 I N THE OCEAN

311

20, The spitwning bc.haviour of shrimps is describcd. The lower rncso- and bittliypelagi(*spccics produce larger but fewer eggs and lnrviw rthtivc to the epipcltigic s p c i c s . In tiny one species a big fcmitlc H ~ ~ W aI grtvikr ~ X nrimbcr o f c g g ~than H smctll. femnle. Thus tho numbcr of eggs prodriocd by i t Rhrimp is dependant not only upon the sizes of tlir egg but also upon 1 h r volume of the parent. 31. ‘t’lie spnwning of epi- arid mesopelagic sergestids is usually hrnviest driring suninic’r in 1emperate regions. That of the carids takes plitctx in spring and autumn. Apparently the spawning of shallowliving pcnaeitls and sergestids in the temperate regions is related to temperttture. whcress it seems t o be related to wind direction of monsootis and precipitation in the tropicti1 region. Probably spawning of lowrr mew- iind bathypelagic carids occurs during much of the year. 22. IJndcr normal condition, pelagic shrimps grow to maturity passing through the following developmcntal stagect. The number in pmwithrsis means the number of instnrs.

(?enrtcidas: n;aiipliuH ( !)-protozoea (3)-zoea (4)-post-larva Srr!pyteAqcind Nerqia: nuupliua (2)-protozoea (3)-zoea (2)-postt-larva Pp/nZidiurri:nt~riplius( !)-protozoea (3)-zoea (I)-post-larva

Acetes: nnuplius (3)-protozoetL(3)-zoetl( I )-post-larva I,~ir.ifev: n i ~ pl u iiis (2)-prot,ozoeu(3)-zoca (2)-post-larva I’asiphu~niand I’crrrcpmiphp: zoc”~(4)-post-larva Oplophor us, 1!ym c> nohra and S,tjelelk(ispis:zoea (6)-post-lttrva ..3cwrrth~ph,tjrn:zo(vi (7 or rnorc)-post-larva

23. ‘l‘he criticttl period of 8erqia lwens exists soon aftcr it begins to feed on phytoplankton in the protozoeal stages. The highest mortality during its life history is in the larval stages. The greatest factor affecting flwtiiiitions in abundance of 8. lucens appears to be the tttwiprwitiircdriring the breeding season. 24. The lifc-span of the species in the genera Gennadm, SergestPs and Sergia in epi- and mesopelagic zones is considered to be one or two years. Them are two tlypes of generations in dcetes japonicus: the longcvity of ttir short-term gcmerution is less than three months. whereas thirt of t h o long-term generation is nine to ten months. Probably the species of Oplophorw A cunfhephyra and Systellaclpicl attain sexual maturity in t3heBecond, but mostly in the third, year of their lives. and produce a sequence of hood8 within the next one or two years. l ’ h ~longevity of such hithypelagic shrimps as Hymenodora is ttssumcd to 111) to 5- H years. 25. Epipelugic and upper mesopelagic shrimps feed on living prey and decomposing dead material which are moRt common at the time

312

MAKOTO OMORI

they were caught, although sniall crustuceans are the main constituent of the food. 26. The membor of the pncra Rergesles, 8ergia and Acetas can utilize food over a wide range of sizes, iind swallow larger pieces, while Bantheogewn emn, Gmnadas, Pasiphnaa , Optophorus and Acaiithrphglra lire adapted for tntinipulating rc:ltitivcly large prey, and the food items are chopped and ground into smiill pieces by the mouthparts. 27. Hpipelagid and upper mcsopclagic shrimps feed chiefly on herbivorous copepods arid euphausiids. Sergestids are potential filter-feeders and occasionally eat phytoplankton, while bathypelagic shrimps take mostly carnivorous copepods, ostracods, medusae and chaetognaths. 28. Shrimps feed actively at night. However, physiological evidence suggests that the lower meso- and bathypelagic species are able to maintain thoir predatory activities throughout their range of migration, by day ns well as by night. 29. The iiauplii of the penaeids and sergestids do not feed. The larvae begin to feed by filtering suspended matter including phytoplankton at the first protozoeal stage and then tend gradually to become omnivorous after the zoeal stage. The larvae of carids subsist entirely on the internal yolk during their early stages and adopt the feeding behaviour of the adult fairly quickly after metamorphosis. 30. The species of the genera Acetes and Lucifer must play a significant role as the food of fish nnd shrimps in the coastal waters of the tropical and subtropical regions, particularly in mangrove swamps. The importance of pelagie shrimps in the food webs of the pelagic community is described, and the many kinds of predators reviewed. 81. The water content of pelagic shrimps is 7,5-860/. Total carbon content varies from 40% to 64% of dry weight, whereas nitrogen content ranges from 6% to 120/,. There is a tendency for deep-living apecies to have a higher carbon-nitrogen ratio. Ash content is 6 1 6 % . Protein content varies from about 36% to 72% of dry weight. A clear difference is found between the protein content of the shrimps occurring in the epipelagic and upper nmopelagic zones and that in the bathypelagic zone. Lipid appears to be more variable than protein ; it ranges from 2% to 730/6 of dry weight. Deep-living species have relatively higher lipid contents thnn dhallow-living species. The lipid, and especially wax esters, appear to be primarily a reserve energy store for the developing embryos and larvae and secondarily an aid to the buoyancy. 32. The contribution of the species of Acetes to the local fisheries is great in the Indo-west-Pacific region. Presumably the annual catch

T l l l DIOIAMIY O F PE:I.AUl(? RFlHlMPS IN THE OCEAN

313

of A c e ~ e nfrom thcw exrccds l5yoof the total catch of shrimps in the

world. The anniial yield of Sarqia Zucanst from Suruga Bay reaches 3 800-7 500 tons. 33, The inorewe in knowletige of'the biology and ecology of pelagic shrimps niunt Icad not only f o t1he improvenient of present fisheries but iilso to the tinding of new stocblts of rinexploited shrimps. Need for more information on the life of Acetes should be emphasized.

XI 1. A(:KNOWI,EI)BEMRNTS I t is its pI(muro t80 thank thc: following persons for their helpful c~itiaisinstind for ciwcfiil reding of the manuscript: Dr F. A. CIIi~ice,*Jr of tho Notional Museum of Natural History, U.S.A.; Mr P. Poxton of the National Institute of Oceanography, U.K. ; Dr J. Munohlinr o f thv Du~istaffn~tge Marinc? Research Laboratory, U.K. ; Dr W. G. Petiwy of t h e Oregon State University, U.S.A.; Dr D. I. Williamson of the Univertlity of Liverpool, U.K. ;and Dr J. C. Yaldwyn of the Doniinion Mustwm, New Zealand. Many colleagues throughout the world have hclpcd to complete this study either by answering lctters or sending specimens. AINOI received much information and help from Hcitwtists in the various corintrics of Asia, Europe and North Americii I visited during the period when the manuscript was bciiig prepctrcd. Although I cannot mention everybody, I thank them all most sinoerely. Dr A. K. Tham of the University of Singapore, Mr J. Y. Wnltcrs of the University of Hawaii, I)r S. T. Zimmerman of thc Oregon State University and Dr Y. Aizawa of the Ocean Research Institute kindly tillowed me to refer t20unpublished data of their own and provided various suggestioiis. I am cxtremoly indebted to them for their generous cwoprration. Thanks arc' also due to Jh It. Marumo and staff niemhers of tho Ocem Itcscctrch lnntitute for their comments tLnd help. NOTE . i J > I ) E r J IN

I'IWIJP

Knowltxlgc* of tho lipicl conttrnt atit1 it8 componitiorl of varioiio npwiefi wax innnmwtl hy nnalysra by Herring (1973) sntl MorriH (1973). Tho lipid content of fctmalor and gravid ftwmlus in gonorally highor than bhst of males snd juvenjlon. In the f p c i e ~ vf l'ericlm thcr prcentage of lipid in tho small eggs (Acuihephyru and Parupunrlnlw) vsriocl from 6 to 17yo in wet weight, whercas that of the large eggs (Oplophorne and S p V e l ~ f r a p ' e ranged ) from 37 to 39%. \\'ax (!stera were particularly rich in the hepatopanorem lipids of t.he ltmver mosopelagic and bathypelagic npeaies. According to Morris ( 1973) the fonialtw and gravid femdew oont,ain high levels of monounnaturated acids and tho egg" of soma spocies &Q compoaed mainly of phospholipid anti triglyceride. ,' 1htt compoaitic~nof t,hc polyunsatiirat~cd aoidn i* affoctecf by both sex and maturity rl i ffert+noos.

Hclrring ( 1973) malyaed tho carotenoid pigments of various shrimps and discuseed the pigment patterns in relation to the depth distribution and light environment. As a

r ~ ~ s oho l l ~H ~ I ~ \ I ' O I,)I&L~, I~ I )I(! viil1!)1o I 1 ~lli.rltn~:~m irk t 110 ul)])octrarlrtt01' upcscic+s,e.g, half-rod HIII.~III~) IIII(I I L I I - I . ~ I I X ~ I V I I I ~ J )FI.I)II~ . I I I ~ ~ I O~ c ~t ~~~ ~t ~. tII I~I~ ' ~~ R I ) I Inrt) R I~~rg(bly (1110 the tlixp11xit,i1111 III' I I ~ ~ I I I ~ a1111 ~ I I ~IIOL ~ H t c ) I I ~ I T I * v ~it1 - Iti1{,1~1 I c ( ~nrnount, of [~igriic?nt,s relntivt: to bc~dy H~ZI'. HI! 11.1st1 I . I ~ I ~ I ~ I IL~ ~I I(L~Li~l ~ l I I I ~ I H ~ 11f10ii.s . (.he!rrll~jor.c)1' ollly. (?~~rot,~?ll~ids present arere nrt,r~nnnt.I~i~~ nlrcl i1.x or1 tbrrILIIII / ~ . P . I L I . O ~ O I I ( ~ 'rhr . /3-~nl.ot,t>no iu l z ~ ~ o nu~anproclirsor of fo11111lin I I I O H ~ 01' thn orlphausiitiu containing ric-h v i l . u ~ ~.4, ~ i rI)llt ~ htlu riot ro filr I>cs111 vita111i11A.

Horril~y.1'. .1. ( 1!)7:3). I)cyt,t~tli~t,rit)(ltiol~ ( ~hht* f curotc.rloid pigmontx antl lipitln of Homo t)r.orlrric:nt~iri~nls.2. J)ornl)l~dCI.IIH~,IL~ORTIH. .loftrnnl of the Marine Hiologirr~lA.mor.,iirlioj~a/' I/I(, 11niLcrl Kir1!/(/07t1,,53, 539 502. Mol.rir, R. q l . ( 1073). itol~t~iorl~hil)~ I)I!~,WO('II t,hv SOX and drrgrcro of inrbtr~rit~y of ~narine RIICI f.tl(*irlil)i(l clrm1~0sit,io11~. .lour~~,(rZ of the Mrr.,.ina lliobgi,'t:ul Amoc!~~urtrtc:crr~t~x e:intt'ot~vf / / ( I , C71vibcd Rittgdomn,, 53, 27 37.

Aizrtwa, Y . ( l!)(i8). fi~cologic-nlst,rliiie~of 1111cronektorii0p r a w r i ~iri the western Doctorttl d~ssc.rtrttion,U n ~ v t r ~ of ~ t Tokyo. y ( I n Japanese.) Nort 11 Pt~c~~fic. Y. (I!)(;!)).Vortrenl (listriI)t~tionarid rlligratlon of rneso- antl bathypelag~c A~ZILWLL, R J I ~ ~ I I I ~111S ~ I I R~~(righbottring SPA of J n p t ~ n . Bulletin of Plankton Society oj Japntt, 16, 60 63. (111 .lnpnr~nun.) Aiznwa, \I. R I I ~Marlllnc~,H. (1907). Vert~(-aIdlstribntion of zooplankton arid ~nicrorrchktor~ bio~nassIn Sagnlr~iBity, central Japan. Information Bulletin on f'lartktolo~ly in Jwpun, Commemoration number of D r Y. Matsuo, 1-7. (111Jnpnti~sc!.) Alcxwidor, H. M. (1972). Tho energetics of vertical migration b y fishes. I n " T h e Effects of P ~ ~ o s s u r 011 e Organisms " (M. A. Sleigh and A. G. Macdonald, R ~ R . pp. ) , 273-294. Cambridge Un~veraityPress, London. Alreruon, B'. G . (1063). Tho food of yellowfin and hkipjack tunas in the e a ~ t e r n tropical Prtcific Ocoan. Bttlletin of the Inter-American Troprical Tuna f7omn~i.u.won,7, 895 398. Apollor~io,S. ( 1909). Brvatl~ri);:ar~tlf c ~ c ~ r r ~ cof l ~ ttho y g l a n ~uhrlrnp, PuKiplu~n na~iZti(lentatu (Dccapodq, Cnritlc,~),111 tht. Ciulf of Mtt~nc*. .Journal r,f the Pi,vherie~Krceurrh Bonkrl r,f ('onarlu, 26, 1 !)O!) 19R:l. 12ror1, Mr.(1!)5!1). Mitlwt~tel*trawlrr~pH ~ I I ( I I V Hin the N o r t l ~T'ao~fic.. L~lmnolog~l and Oc.eanograph!f, 4, 409 418. Raker. A . C'. (1!170). l'lle ~.crtic.slcllntrihtltjo~~ of euphauxilds rrchurE'uc>rtovr.~j~ I I ~ H('nntlr-y . Ixland.~(" D ~ ~ c o v c " * ySollnd Cru~ue,1965). J o u r r ~ u lof the -4lorir1e H~ologic*alAnsociation of the United Kingdom, 50, 301 342. Ihlus, H. (1925). Macrura der Dcr~tscher~ Ticfme-Expedit~on. 2. S a t a n t l a , 're11 A . H'i,~.oenschaftliche E'rgebrcwee tler Deutvchen Tiefsee-Expedition atcf clerrt Dnnrpfer " I.'altlivia ", 1898 1899, 20, 217 315, plates 20-28. R H I I HK. ~ . (IOti4). 011 the vorttcal distribut~onof plankton in the sea. I n " Proglr\.us i r ~O r r e f ~ o g m p l ~ " y(M. Scars, d.). Vol. 2, pp. 53-125. Pergamon l'rt%s..i. Oxford. 131rrhcm1, N. C.: (1!)57). The revlogy of H ~ I I I ~ncuttc,ring . lnyers I I I t h e Montercay Bay nrtw. ('al~fornlu. Hopkinx Marine Station, Stanford C'nivereity, Technical Report ( I ) , I -182.

THE UTOI~OOYOF PEI,A(JI(' SHRIMPS IN THE OCEAH

315

Harharn. 14:. ( i . (1!)63). ' I ' I t c 9 d ~ ~ p - ~ ( ' & % t fIt~yt*r ~ ' r l l lILH g ohnerved fro111 tho bat11y". I'roceetlirtqx qf tthr IBtlr Irrtematlona.?('ongre~xof Zoology, 4, scnpl~" 'r1*1(4xto 298 :100. 13nrnurd, I i . H. ( 1950). T ) I * Y ( ~ I ' I ~ ~(v~titlog~to I\~O of Koritl~Afrlrnrl docwporl Cruntacc.n A n ~ u c ofl ~ the Sortth African Altmerrnb. 38, 1 837. M. (I!)UH). Mic.rorroktaott of t l ~ c~WILI~I'II ~ troprotl I'ac.tfic 0c:cart: ~IlarkL)r~rrr, fiunrly cbornl)on~trot~, drntrtt)tltto~t,ttl)~ittdt~ttc*(~, ttnd I W ~ R ~ I ~ to I I Rt~tltu. iF7iXhery ltctlletirr rf tlrr 7J.S. Fixh and Ct'ilrllift~Sernice, 67, 71 - 1 15. kjI&~kblll'lk,M.,~ A l t U rIt. ~ ,M., o ~ ( ! t l ,lt. \V. lllld %CI~"~CIICI, R. (1970). ~ O & N O I I H ~ trntl tcrclt~lc*Ott~tgc~s 111 nt ~~rrdrtlg hto(~kuof ~ I I toplankton, J zooplankton urtd r~~tc*rottcdctoi~ 111 t 110 ~ a ~ t ~t I ~ of)t(~i11 r t t l'ttcific.. illarilie Biology, 7, 14 31. I3orrt~clutl1*. L. A . ( 1916). Crt~ntac~~~tc J . I)o(.t~r)od~. hratimd HGtory Heport of the 13ritixh A~it~crctic Terra Nova Ir:.rperl~tion(Zoology), 3, 75-1 10. ~ of ei~pha~~rcuds Hrinton, K. (1907). Vctrtrcnl 1111grutiont ~ n do v o ~ c l a n ccspabtltty ill tllo ("nlrforntu (!~rrrcli~t.Li~tbnologyarul Oceanography, 12, 451-483. Brork, V. 14. nnd Hrff~~rtburgh, R. H. ( 1960). I'iel~ uc*hotilalg: a pousrble f i l ~ t o rn r ~+ndircitrg produtiorr. Jortrrlal rltr Corrseil, 24, 307 317. Brooks, W. K. (1882). Ltrrifer, a study tn ~norphology. I'hilo8ophical Trarls1 -11. r s r t i o ~of~ the 12o!jd Societjj, 173, 57 137, p1ti.t~~ of of J A o r t i ~ i a rwith ~ ~ , a (I~sc~iusion I3trrkonroiid. M. D. (1!)34). The I'orrt~c~rtlet~ tlloir worlcl rolnt ionnltip~. I~rtlletir~of tlra Arnericun M weurn of Aratiiral History, 68, ti1 143. I311rk~rrronfI,M. I). (1!#30). 1'110 Art~tt~'111a0, S01011oc~rinne arrd pelagic Portaeinae of thu 13111gIttt11t O c ~ l t ~ ~ o g r aCollect~on. pl~~c Bulletin of the Bingham Oceanographic Collection, 5 (2), 1-151. 13trrkonrond, M. I). (1937). Tllo Ttwnplt~tonCrorktw Rxprdition. X I I . Rergestidao (C'rustnct~ttDrcnpodu) from tllo lowc.1. Cnlrforsn~arrrngron w ~ t htlencrrptionrc of two IIRW X I ) ( ~ C I C nrld ~ nonle ro~r~nrlzn or1 tIt(1 orgnnu of Ptmta 111 Sergeah. Zoologicu, Netc~York, 22, 316 :t29. tloxcbr~tpt,ionn of twer~t~y-orto r t ~ wHPC~CIOH l ~ t r l o ~ r o aM d , I . ( ! 4 ) l'rt~l~rni~rary of pt>Ingtc I'or~ttt~~dnt~ (Crt~ntactqtc I ) I W I I ~ Ofi~)111 ( ~ U )t I t 0 Durtrnh 0cc.anogrt~phlonI Expc~tlttior~x.Atrnalx atrtl Mwuzine of Nntfrrul Hiulory (Srr. 1 I), 6, 36 54. Burkc~rrrortcl,M. 1). (1946). A new nc-r~~:stitl xltrtntp (I'euux petrurtkerritchi, 11. gclrr., 11. sp.), with rornnrka on its n~lntrorlnlrtp~.Tranumtunw of the finructicvt .-lcadency of .4rtx n r ~ dScience, 36, 553 B!)3. I n . 1. J ( I ) . ~ C ~ + V I S I O of I I tlrv i)irtJtypoI~g~c prnslru of tltc furnrly Jr~rtrrialelf ~\cctl~tlrr~plryr~tlae, w~tltrlotc~sotr t t rrclw ft~rnrly,(Jo~nphorlot~dac. the 1Vu8hingtolb .4cadetny o j Scie)&ce,26, 24 31. ('lruccr, I?. A. .Jr. (1!)40). 1'1~nktorr of t11r Uttrlr~irdtiOccanograptrrc Exped~t~onn. IS.Tho hntlt)pcllnprc cttrrdo~rr( ' r u s l ~ ( ~ ( ~doologica, u. Xe?u 1-ork, 25, 117?Oil.

Chactr, Lt'. A. J r . (1!)47). Tllca dcclp-nt*aI)I'ILH 11s of tlt(' fanlily Oplol,ltor~darIn thc~ Hrrrgltnrr~O~~c~nrrograplric ('o1lrc.t ror~. I~trlletinof the I~int~harn Ocwnqraphir Collec*tion, 1 1 ( 1 ), 1 51. l k , . I . o r , It. I . , t i I , . N. a N o J . . . ( 1 ) . C'ompnrt~tivc.utlttlrrh of lurnit~esccv~rc~ 1r1 ropcyods H I I ~o t l r ~ rp(>Iag~(.mt~rrn(* nnrrnnlx. .Jotrrr~alof the Illurine Ntologicul A.vsociutkr~of the C'nitrd Kirrgrlom, 42, 541 564. trtr\srlfor wrnpltr~gclrscarotctl~.ptltttorlaortn. Clttrko, M. It. (Il)ti!l). A rtuw ~r~rdwnter Jortrrlal r,f the Alarine Niologirul .4avoricttion of the llnilecl Kzn~johm, 49, 945 980.

316

MAICO’I’O OMORl

(’larkti, T. A. ( I 972). Collt-ctiotiw and biibiiiarino observations of deep benthic fishos ruid docapocl (’runtaccw in Hnwt~ii. I’aci,fc Science, 26, 310-317. Clarkcr, \V. D. (lNi3). l’iinctiori of I)ii)lririiiiitrsc.cncr. in tnosopthgic organisms. Naturc, Londort, 198, I244 12-46. Clarke, W. I). ( I !)f30). HntIiyphotoinoti.ic stixlitw of tho light repine of organisins of tlio (ltwp scnttoririg laycw. .4 .E.C. l h e a r c h awl Development Report UC48, 13iology and M r t l k i n e , TI1~4800,1 - 47. Clutttir, It. I . ( IHB!)). ‘l’ticr niicrocliet~~ibiitioii iuid social hehttvior of some pelagic mysid shrirnpa. Joitrnal o j hkperimental Murine Rwlogy and Ecology, 3, 128 -155.

C:oiitiBro, J . (I!)Oti). Notes stir IU nyrioriyinw c a t l e d6voloppement de quelqirea Hoplophoridat:. (t’ttinpagoox tie In “ Priiicesxr Alice ”, 1904-1905.) Rulletin hf?wEe ucdaiir~gra~,hiclue, Monaco, (70), 1 20. Ciilkiii, F. &rid Morris, 1C. J (1969). ‘I’hc. fatty acids of some rnrtriric crustaceans. f)eep-Sea Reuearcli. 16, 109 - 1 16. lhvius, I. E. i w i Ihwlmn, E. (2. (1909). Tho ’J’iickcr opening-closing microIiekton wt uiid its porfr,nnoiiro i n a stiidy of thc deep scattering layer. Jlarins Biology, 2, 187 -131. clr Man, J . G. (1931). On a new species of tho gonus H u p l o p h r w (Oplophorus) H, M,-Edw., Hopluphorue novae-zeelandiae, sp. n. Journal of the finnean Societ?/ (Zoology),37, 369-378. Doiiiiall, H. (1040). On the structure of the photophoros of some Decapoda C:rustrtcea. “ Discovery ” Report, 20, 307- 381, plates 24-26. Datinttll, H. ( 1 956). Obsorvutions on the luminescence of bathypelagic Crustacea Docapodu of the ljertriudtt aroa. Journal of the Gnnean Society (Zootogy), 42, 393-400. Denton, E..1. (1!)71). Examples of tho use of active t,ransport of salts and water to give t)iioynnry in t l i c HP’A. t’hhih)8f)phid Tramrcctiona of the Royal 8ociety, Series 13, 262, 277 -287. Dietz, R. S. (l!M8), ‘(.lie son’s dwy scnttrriric layom. KcientiJc American, 207 (2),

.

44-80.

Drwgovic.h, A. (l!W9). ICevicw of Htiidit*s of tiir irt food i i i the Atlantic Ocean. h‘peciul Scientijr Report (4the t 1 . 8 . Piult and Wildlife Service, 593, 1-21. EIof~noii, I t . (I!)(il). ‘I’lici larvae o f f’nsipkaca mftlticii titab (Esrriark) and pa&phnea f n r i h (ICraycr). &zrsin. 4, 43 53. Fagetti, E. arid (‘ainpodorrico, 1. ( I ! V I ) . f,>irvrtl cIcv olop1nent of the red crab 1’leuronc.tnZe.u monodon ( I>ecapJdtI Aiiomiira : Galtit IicidacJ under laboratory coiiditioiis. Rfurirhe Hiology, 8, 70 81. 14giieirtt, A . J . G . (19.57). Mttdrriruii d~(~iipoiI crustaccwin iri tht. collection of thc Miistw Miinic*ipaldo Fiinchsl. I . O n *inno inter(*.rtingdeep-sea prawns of t h e fuinilins l ’ i i ~ i r ~ t r t i t ~ i ~0plophi)ridnt~ lti~~, rind Pantlrilidrtc. Boletim do Muaeu AfltJlicipfJl d0 Fft’?t(:hd(lo), 2 2 51, phtlY 1 4. Vislier, 1,. R . (1063). The total lipid rncitoitctl i r i H O I ~ I O specica of rnarinc zooplank t o r i . Uapport et l’rocds-i3erhau.r deh H4union.u. Conseil permanent internationul p t i r 1’E.c.plvralion (la In Mw, 153, I2!t -1:M. Ii‘inlier. L. Ti. r t i i t l Golclio, 14:. H. (1961 ). New rccorch fw t w r ~tlortp-wa dCCapOllH. Critxtac*eann.2, 78 79. Wisher, L. 1t. arid Kon, 8 . l i . (1!15!j]. Vitninui A in irivcrtsbrittw. Hwloyicul Revieu*u, 34, 1- 36.

TlIE BIOLOCII’ OF PICLAQIC SHRIMPS IN THE OCEAN

317

E’idior, I,. R., ICtm, S.K. arid TIiortit)xoti, 8. Y.(1965). Vitctrniu A rirtd carot,wioidH in ccrtiiitt iiivert,th-ntRtPs. 111. ICii~~ltttiintaceri.Journal of the Marine Ilioloqicul A ~ ~ o c i u t i oofn the lTiii/c t l Kiiigdoin, 34, 81 100. Fishor, L. R., Ken, 8. K. end ‘l‘lioitq)tm~,8 . Y. (1987). Viturnin A arid oaroterioids in cnrtniri itivertmbraton. VI. I’ontwicloa. Journal of the Marine Biological Aaclociation of the United liingtlonb, 36, 801 507. Food and Agriculburo Orgnriizatioit of tho Unitcd Natioits (1971). Year Book of Fisher?/ Stntixtica, 30, i xxii, 1- 476. Forsyth, I). C:. 1’.and J O U ~ RL. , 1‘. (1966). Swarming of Thyaanoeeaa Zongicaudata (Kruyer) (Criistuccn, Ii~iipIiiiiisicLcea)in the Shetlaiid Islands. Nature, L O ~ O 212, T ~ 1467, 141i8. I’oxton, P. (1964). ObHwvatioiis on ttic cmrly dc~velopriiantand hatching of the i y q p of Acattthephyra piwpurea A. Milne-Edwards. Cruataceana, 6, 235-237. 1Toxt011,P. ( 1 0 7 0 ~ ) . Tltti vet.ticctl tlistrrhiition of pelagic dt-capods (Crustacea : Nutatitiu) oollectnd 011 tho Sorid cruise 1966. I. The Caridoa. Journal of the Marine Biological A ssocintion o j the IJrbiled Kingdom, 50, 939 -960. Foxtoii, Y. (19iOb). Tlie vcwtical distribution of pelagic decapod8 (Crustacea : Nataritia) collected on the Sorid cruise 1966. 11. The Penaeidea and general discussion. Jotcrn~al of the Marine Biologicul As8ociativn of the United Kingdom, 50, 961-1000. Foxton, Y. (19724. Furtlwr evidenco of tho taxonomic importance of the organs of Yosta in the gcwris Sergeate8 (Natantia, Pentieidea). Cruataceana, 22, 181- 189,pl&1 1. Poxton, P. (1!,72b). ~)bnorvatiortHon tht) vertical distribution of tho geniiH Acanthephyra (Criistarw : Dectipoda) iii tho eastern North Atlantic, with particulsr rc-fcrmnco tc, npociox of thcr ‘ purpurea ’ group. Proceeding.? of the Royal Nociety of ZMinbtrrgh (H), 73. 301- 313. Foxton, 1’. tind Howlrig, 1’. J . (1!)70). Heccwt records of I’hyaetocaria microphthlma C I I ~ Cwith H riotos oil tho rnulo ttnd description of the early larvae (Docaptda, (!andoe). Crustnceuna, 18, 93 -104. 14’rwor, J . (1962). ” Natura Adrift ’’. Foulis, London. Gontlin, H. C. Jr. (1909). The reproductive biology of Sergeatm aimilia (Decepoda, Nattuitia). Marine Biology, 2, 203-217. Gordon, I. (1955). fmportmce of larval characters in clewification. Nature, London, 176, 91 1-912. (hrney, R. (1924). Crustacca. I X . Decapod Iarvm. Xutural HWt0ry Report of the British Antarctic Terra Noua Expedition (Zoology). 8, 37-202. Gurney, ft. (1927). Larvac of tho Criietncea Docapoda. Report on tho zoological mmlts of the C‘amhridge Expedition to tho Suez Canal, 1924. T r a m u c t i ~ of the Zwlogical Societg of London, 22, 231-286. Gurney, 11. (1942). Larvae of Decapod Crustacea. Ray Society P u b l i c c r t h , 300 pp. Gurney, R. and Lobour, M. V. (1940). Larvac of decapod Cruatacea. VI. Thr: gnniia Sergeete.9. ‘‘ IXacovery ” Report, 20, 1-68. Grirnoy, ft. and Labour, M. V. (1941 ). On tho larvae of certain Crijxtacr?aMacnira, mainly froin Bormuda. Journal of the hinnean Society (Zoology),41, 89-181. Hale, H.M. (1941). Docapod Cnistacea. Report ofthe British A . N . Z . Antarctic ReRearch Expedition (Ser. B),4, 267 286. Hanson, H. J. (1919). Tho Sorgostidae of tho Siboga Expedition. Sibogu Ezpedition, 38, 1-05, plates 1-5.

Hansarr, H . . I . ( I!)"?). ( 'ruutr~c*t I0hst.rvnt.io11 of t trc. vc*rtic!ul tniq-&tiort of Sergento.9 11~:en~ ) H ~ i . t (I i ~ ~.140. , (111.Iapanocic!.) Hn,r~sc.rr fi~lt-!irldf!r.1 I ~ f / t ~ i c t ~ /9,l ?14:j s o I . I . ( I ! ) Stirirr~pIinreery; scicncc! nxplort:s nc:w I , . . L \viytx t o frrr.111t,hlxsrc~.L9Tatr:onul C:eo!lruyh,ical Magazine, 127, 636 659. J k t ~ ~ n ~ t t\2'.(1!)53). ,s~~, Orr t11r lifc!-l~i~t~)ry of A c e t a ~japonicue Kishinouye in Atqinkt, Stan. 11ztllr.lin o,f lltr ,Jul~lneseSociety of Scien,tiJic Fiuherieu, 19, 771780. (111,Iltparrrsf~.) Ikolnt~tau,W. (1!)65). 0 1 1 tllo lifw-hist,ory rtf Metapenaewa joynem' (Miers) in t21.irrltc. 81\11.. Itrrllcfi?~of the . I n p n ~ ~ e ~Societ?) se of Scientijc Fisheries, 20, 969978. ( I n .ltlp~tncuc..) I k a m t ~ t s ~\C'.~ . (1!)57). An ~st~irrrrttionof ac.cnlar variation of " Ami " (Acetes jrtponia?ra trnd ~rrysis)yicM l > ~ s e dor1 tlrc past records of cat,ch statistic in Stlpac 11rcfrc:t1rrc1. &?fl(~rt of t11.e Jnccsti
THE BIOI,OOY OF PEI.AOIC RHHlMPS IN THE OCEAN

319

Inlmcs, J . 1). anel K ~ r i d J,. , W. (1953). l a t u ~ ~ s - l i ~~ dn it dl w a t e trawl. r Flrlal Report. S(.ripp,v In~trt71t~orr t f Ot*eunogrrtph!l, Hof. 53 3, 1- 18. R. (2. ( 1 !)70). 0 1 1 tho biology of' t l ~ c tAntarctic krrll Er~phat~sia superbu. IVILIIOV, hlt~rirtrIlitrloyy, 7 , 340 :{RI. I botly niKe a n d ~ ~ r ~ r n of b r eggs r In '1'1h1, I - ( ~ L I ~ I O Ibot,\vot~r~ l l l ~ l l I, . I . (1!58). rntwltrrx M t ~ l t ~ ~ o u t r t ~Meddelelx~r.fra k~s. liommisxionan for I)nn+t,arks I"iske9i og Hal-unttcraogelarr, Now Sc.ri(~a.2, (I!)), 1 25. R N Irldia. Proceedings of the .lonos, H. (l!)ti7). 1 ' 1 1 1 ~ cruntacenn fisI1t.r) I ~ R H ~ I I ~ C of S y m p o ~ i r ~ on t n ( ' r ~ ~ ~ t u c 4, e a ,1348- 1340. J~lclklnrr. D. ('. and L~'lern~ngor,A. (1!)72). Cornpiirison of foregut contents of Ser!qc.~tex ~ i n r i l ~ol)talnotl s from not rollectior~s a n d albacore stomachs. E'inlteyf I~t~IIetirr, 70. 217 223. lic\~np,8. ( I!) l Or,). Not08 on tho plrc ~topltoreuof doctlpod Crustacca. Proceerlinp of the Soolor/ical Society of 1,orrrlon (1!410). 819 fiS1, plates 52 54. ICct~rlp,S. (19101)). Tllo Dncnpodn Nattlcrtict of tlrc, coasts o f Ireland. Scierrtijc lnctextiyntions of the E'isheries Branch, /)epartment of Agricultctre, for Irelarrrl, 1098, ( I ) , 1 190, pltttes 1 23. Kt-~np,8 . (1917). Notos on C:rustucoa Dttcapoda in t h e I n d ~ a nMuscnm. VIII. 'J't1e1~ C I I I I R Acetes. M~lrto-Edwr~rds. Ziecorda of the Indian Musezcm, 13, 43 5 8 .

n . ( 3 ) 0 1 1 Acantheplhyra pctrptrrea a n d its nl11cs (Crustaccba, I)cwupotltt, Hoplopllor~dm). .4anals and Alayazine of Natural Hietory (Soricw 1I ) , 4, GO8 579. Kcmsley, 13. P. (IOTI). Tho falrlil) Sergcwt~cicto111 t h waters ~ aroclnd solltllorn of the South African Afrlre (Crunttbc-IS&,D(jc*c~podu,N u t t t ~ ~ t l ~ )Arlnals . Alr.wer~trs,57, d l 5 2ti4. i nt h e comnloll marine Icing, *I. E. (1!)48). A s t ~ t d yof tho rc.protirrct rvct o ~ t ~ t of ~lrrrrny, I'erraertr setiferrix ( I A ~ ~ r ~ r t t o t Illoloyiral ~u). l j ~ ~ l l e t iofn tlte Marine Riological 1,cth~tratory. U'ootls Hole, 94, 244 262. Kornrtk~, Y. (l!)(i7a). O n t J ~ esrlrfacct xwar~ningof' eupl~auuiid crustaceans. l ' t i c ~ i cScience, 21, 433-438. Kornctk~, y. (l!t(i7t)). On the ittt~ly l n c ~ t c ~ l ~ l ~ ) l ~ofp t l~ematoxcelie o~~s dificiliw Hnr~xc~ri (E~~pl~n~ts~ Cr~~utac~c.a). nrt~a, Irijorrrration 13cllletin on I'lanktoluyp i n 1111ln1,c.r. o f I l r Y . Mt~tn~rc~, 1 0 1 108. ,lapafr, Ce>~n~ncvnorat~c,n I i o ~ n k n M., . Krlhotr~,'I'., Ogrtrtr, M.,O ~ ~ 'I1'.Lr,t r t c l N t ~ k a Z. ~ , (I!fG!b). SLucllc-~crf'thcprcrtli~torynpncBrt>n on t i l t ) nllrtrnp, Serqesle.~l~rcennIn S11r11gtiI~ILY.,/ourru,il cf the Colleye of Jlorirre Science and l'echnr~lo!~y. Tokai linicerffity,(3), 87 1 0 1 . (111 Jiq~ur~csi*.) lcubo, I. (1951). J31e)1io1mrsof ttro prnwn, / ' a n d a l z ~ke~slerzC z e r n i a v ~ k ~Jvltrrtul . (4the Tok!/o Ij~rir)ers.Bity(# Fkheries, 38, 1 PO. I ( t l b o t ~ , ti11(1 Ilytr110, 'l'. (1070). b'ood Ilnbita o f lancetfish Alepkattrzc8 feroz (ordor Myctot~l~~forrnt.s) 111 Mun~gn13cby, .lttpnrl. .Jaynrreae Journal of Ichthyo/og!/, 17, 22 28. I I J I M. M. ( 7 0I)s~rvntlonnO I I thct prawn fisllcry of nfal~arii~l-rtra coast. l'mreetlings of the S,y7~yoai1irn or1 Crrrxtac~u,4, 1382 1397. Klll.~ttl,H . ( 197 1). ( 1 F I ~ H ( ' IH ( ~ ~ I ~ I I /?I I ~"~~ ~e l. l] k ~ l - k i l l l % i ~ l".~ ~ o ~ ~ ~ ~ k ~ ('I'. 11nc11,catl.). ~ q j 297 . 343. K o ~ e ~ ~ l ~ f l - k o s ~'I'okyo. ~ ~ k a k(111 ~ l ..Japallcse.) . Bartlcjtt, A . M. (1!b71). D ~ e t n b i i t ~ oand t l ~rnportarrcc~ Lco. 1t. F..H I I * ~ ~, I .I Ictncl copepoda rt~ldot11r.r zooplurrktorl. Deep-Sen Hedearch, ~ )\vex f e~rrtizrnI I I ~lrarir~c 18, 1147 -1 111.5. J

320

MAKOTO OMORI

Lo ( i i ~ l l ,.I . - Y . tind L’Hnrrciiix, M. ( 1 117 I).Mic!ronocton en McditcrranBu occidoiiitilcr ~ t t)riwlto , A l I t ~ i ~ t i ( ~ i i (JkiriiiOos t: ~111aiititativ~~ et comparaisons. IhjiImrLu xcit-t&tijique.vrt teclrniquex, f h t r e national pour 1’ETploitation des O I * ~ f l ~ L S( ,1 ), I 32. Lo Gall, J . - Y . ILJIII I,’Herroiix, M . ( 1 972). Chistarcis pdlagiques susceptibles de p6ctic8s expciriinonLfllr,sen Atlnnticlua Nurd e t en Moditerran& Occidcntale. ii‘apporta ncientlfiquea e6 techniques, Centre national pour 1’Exploihticm des OrJane, ( 8 ) , I Xi. Lngand, M. (1!)09). S(wxurii1 vnviiitioii 1 1 1 the Tndian Ocean along llOOE. VI. Mncropltinkton atid inicroiioktoii biomass. Auetralian Journal of Marine and >’rentwater Research, 20, 85 103. IAc.pc*ticlrct,JC. (1!)4O). Ltt f i i i i t i o pAlagiqiic do I’AtIaritiyiie at1 large du Golfe de Uaseogii~~, rwii(dIic duns drs ostornacs de Germons. TroisiOme partic : lnv(rrtBbr6s (cBphalopodes oxclus). l’arasitos clu Germori. Annalea de l’Z%*titid ocknnographiqwe, Monaco, 20, 127- 310. l,eiw, H . t u i d Ht,riiric:k, K. (1814). I)io Dvkapodm der Deiittwhun SudpolarExpodition, 1901 1008. I. Rrtirhyitreri und Macruren mit Auischliiss der Serpstidoii. Deutache Swdpolar-Expedition, 15, 257 -346. 1,e Hosto, I,. (1970). Biologie do Acetes ergythraeus (Sergestidae) dans une baie du N.W. dc Mudagascar (Bale d’Ambaro). Cahier O.R.S.T.O.N. Sdr. Ockanographique, 8, (2), 35-58. Lowis, 1C. W. (1967). Fatty acid composition of some marine animals from V~LI+IDIIHctopthr. Jorirital of the Fisheries Research Board of Canada, 24, 1101 -I 115. Liu, J. Y. ( 1 ! 6 8 ) . Notes o r i t w o spttci(iR of Acetes of the family Sergestidae (Criistaccrti I ) O C M ~ O Cfroin ~ H ) the cwasts of Nortti Chiiia. Acts ZoobgiCa einiccc, 8, 09 40, platox I 4. ( l i i (‘liinew.) Longhurxt, A. IC. ( 1988). ’I’lie biology of irinss orriirrrnres of galatlieid crustacmns mid tlroir ril ilixiitiori i i X tt fislicrit.s roxoiircr. F A 0 Fisheries Report, (57). 2, 95 110. Lon~hurst,A. N.,I,orc~iizoii,C. J . iiiicl ‘l’liointis,W. H. (1967). T h e role of pelagic crnbs 111 tlio griiztnp of pliytoplwiktoii off‘ Haja Ctlfrfornia. EcoZogy, 48, I!)O 000. Mary. ,I. \V. S. (1962). Tlin iiatiirtil history i i n d gwgraphy of tho Antarctic krill (Etiphatt.na sitperba Dnria). ‘‘ Dincovery ” Report, 32, 3 3 484. Matthcwn. . I . B. I,. i m l Piniioi, S. (1Y73). Ecological studies on t h dc?op-wat,c*r palngic c*oinniiinityof Korsfjorderi, wrshterri Norway. ‘l‘hu sp(*ciwof Pan& phma anti Serqedes (Crusturna Decapoda) recorded in 1968 and 19f19. h‘arnia. 52, 123 144. Miittliewn, L. H. (1!132). Lobstc~-krill. Anmnuran crustacc.ans that are thc food of whiilrs. “ Discovery ” Report, 5 , 467-484. Maucliliiic., *J. ( 1‘372). The biology of bathypclagic organisms. especially Crustacetr. DeepSea Reaearch, 19, 753- 780. Maucltliiitb, J . and Fisher, L. R. (1969). The biology of eupliausiids. I n ‘‘ AtI\ciiicos in Marine Biology ” (F. S. Russell and C. M. Yonyr. eds.), 1’01. 7, pp. 1 454. Acadeinir Press, TAondonand New York. McCowin, -1. A. niict Brown, D. M. (1966). A ncw opening-closing paired Z(JOplankton tint. lTniver8ity .f California, ,%rippa Imtitzrtion of Oeeanograpk!/,

Ref. (i6 23. 1 -56.

T l l E L{IOI,O(IY OF PELAGIC: SHRIMPS IN THE OCEAN

321

McHugli, J. L. ( 1 952). Tho food of alhtlcoin (Uermo d d i t n g a ) o f fCalifornia and Ijltjtl (hliforrirn. Hulletin of the S'crippe lnatitvtion of Oceanography, 6, 161-

172.

Menoii, M. K . ( 1 X33). 'L'lio I i f t l - I 1 i s t o i * i w of dwaporl Cni~tcEcculfrom Madrtw. l#ti/lrttu I $ /tw . I l r r l t w t h w ~ Wt W W J ~. t~l t t s o r m ( N w Nenrwt X ~ J ~ I U tliatrv!~, U/ 3. (31, I 43. p i * w I 10. M i c h l , A . utid Orulidptm*ru, tC. ( 1 Mi!)). Apsryu SUP la d ~ t ~ * t b u t\rertwale ~on du rnicroriocton duns lo Pucifiquu ouest Bquatorial (170'00E). Cahier

O.H.S.T.O.M. Sdr. Ocdanographique, 7 (2).46-52. Miyuzeki. N., Kusnka, 1'.firid Nishiwaki, M. (1973). Food ofSteneZla cut?rulcdba. Scientijic Report of the Wholes Research Znatdute, Tokyo, (26),205-276. Morris, M. C. (1948). Life-history of an AuRtralian cruetmean, Acetea auetralie (Dccnpoda, trihn Periaeidae). Proceedinge of the Linnean Society of A'ew South Wale.9, 73, 1-15. Morris, It. J. (1972).The occurrence of wax esters in crustmeans from the northeast Atlantic Ocean. Marine Biology, 16, 102-107. Murray, .I. arid Hjort, J. (1912). "Tho Depths of the Ocean". Mmrnillan, London. Nakai, Z.,Kouakrt, M.,Kubota, T. and Ogura, M. (1966). Outline of the first survey on the predation of Sergeatea liccena by Ash in the Suruga Bay. Jourtmi of the College of Marine Science and Teohnology, Tokai Univereity, ( I ) , 171. ( I n Japanme.) Nakazawn, K. (1916). [On the development of " Sakura-ebi ".] Zoological I).lagazine, Tokyo, 28, 485 494. (In .Japanese.) Nakazawa, K. (I932). [On the rnotamorphosis of '' Sakura-ebi ".] Zoological Magazine, Tokyo, 44, 21 -23. (In ,Japanese.) Naporrt, T. A. (1964). The effect of hydrostatic pressure on the prawn, Sy8tellasp& d e b i l k . Narragansett Marina r,ahoratory Occaeional Publication (2), 92--91. Nataraj, S. (1947). On Rome RPHCIW of Acetee (Crustacea, Bergestidae) from Travaiicortt. Record8 of the Indian MU8eu??&, 45, 139-148. Nath, P. It. (1966). Biology and Hoa8oiiul diHtribiition of the pelagic food fishun of Travancort+ CoaNt. Bullet?ta of the Department of M w i n c Hiology and Oceanoyraph!y, Univeraity of K w a h , Special Put&ation, 1 I 40. Nevctnzol, J . C. (1970). Occurrcricv, fiiric!tiori a r i d biosynthonin of wax eNtom I I I rnnriric- orgmiiemn. Lipide, 5, 308 31 0. NIWOIIZO~, J . C., Rodogkor, W., liobinson, J. 8. and Kayama, M. (1969). Thc? lipids of some lantern fistiiw (fiitnily Myctophidae). Compamtive 5 i o chemhtry and k'hyewlogy, 31, 25 -38. Nicol, J . A. C. (1958). Obmrvationn of lumiriwccrice in pelagic animals. Journal .f the hfum'ne Biological Aeeociation of the United Kingm, 37, 706752. Ohta, S . and Otnori, M. (1974). Oh~ervationof behavior of a sergestid shrimp Sergeetex lucme Harisen by underwater photography. Journal of the Ocmnographical Society of Japan, 30, 86-89. (In Japanem.) OkH-da, Y. K. (1928). Note on the tail-organs of Acetee. Annals and Magazine of Natcirul Hielory (Series lo), 1, 308-310. Oinori, M. (1965). -4 100-om opening-clokng plankton net. I. Description of thc: gear. .Jovrnal of the Omnographical Society of Japan, 21, 212-220. Omori, M. (I96Qa). The biology of a sergestid ehrimp Sergeutce lwena Hanaen. Hitlletin of the Ocean Reaearch Jmtitute, Undvereity of Tokyo, (4), 1-83, plate 1.

0111or1,11. ( I9ti!)lj). M'o~gl~t I I I I ~ IC I I I ~ I I I I C - ~ Irotn~)osition I of solllr 1inporta11toceanic I I I tlrt. Nort 11 1'~1<.1fic. 0c.cxnl~.nla7tt~eSioloqy, 3, 4-10. nool~lai~rktor~ I O I I M I ! ) I'rocluc.t~\~ t y01' zoo))lnr~ktonIII tl~trsea: Prohlc~lnn111 r r l a t ~ o n to s t r ~ d y( , t i Serqe.vtru Itrcer~mI I I S I I ~ I Itny. I ~ L J ~ u r n a oj l the Oceanographical IS~ociutyoJ'./apatr, 26, 212 252 (111.ltipar~rae.) ~ c ~ a t rr x~pnc ~~~ ~ ~ ror1 n ~t rh~e tlarvae s of Seryextes O l n o r ~ M. , (197 In). I'relrui~~~trry 1ucetc.q (I'cvraeidt~a, N ~ t n n t i n ,Dctcapodu). Afarit~eBiology, 9, 228- 234. om or^, M . ( I 97 1 b). '1'&xorron1y R I I C 801n(~ ~ nottjs 011 t \I(' b1010gy of a new carldran sl~rwl~p.l'l~aiortika izr~miae ( D ~ r u p o d o ,I'n~~dalidar). Crtistaceana, 20, 241 650. 01nor1. M., Kr~\val~~ilru. A. urld A~znwti,Y. ( 1 !)72). ~SergeutPmuintilix Hmsen, ~ t s d ~ s t r r b n t ~ oa11(1 r ~ I I I I ~ O ~ ~ R IAS IC~ foc~d ~ of fill U I I ~set whnles 111 tho North O c o n r ~ o g ~ a pof l ~ ytho Northern North Yaclfic Pnctfic Oct3t1.11.111 " I%lolog~rnl 0rcvt11" (A. Y.' l ' t ~ k o ~ ~ et o ral, ~ t ~txds.). pp. 373-3!)1. Ttletnitau S l ~ o t e nTokyo. , .'l' n11d Noye, K. ( 1973). H ~ s t o r yand present n t a t ~ l sof t h e Ornorr, M., Kort~gttyu, Z U C C ~ S (Por~ntr~dehrt, Drcapoda, Crustacoa) In 8ur11gaHay, f i ~ l ~ ( -of r y ~S'erge~te~ . l s p n ~ ~./o?trttnE . tlu Con,~eil,35, 61-77. l'utl~ansc~l~, D. (I!)B6). Acetes (Sergcat~(lao)from Malay P c r r t r ~ ~ ~ ~Jiulletin ltt. of the Nntio?~alMuseum of Singapore, 33, 5!) 63. I'nxton, .I. H. (l!)(i7). Blologlcal r~oteson tllo soutllern Cal~fornlaIautrrr~fishrn (farnrly M yctophidae). California Piah and Came, 53, 214-21 7. i'car~rcy, I\.. G. iir~clForns, C. A. (1 966). Depth d~stributlonof oceanic shrimps (Doct~podt~: Nutantla) off' Orc.gon. Journal of the Piahen'e~Research Board of Catlcula, 23, 1135 1143. Pot~rcy,M'. G . a n d YOI-an. ('. A. (1969). Thr, oceanlc shrllnp Sergestes similis ofl'il~e\<)rt\go~rconst. Linanology and Oceanography, 14, 7 5 5 765. I'tvtrrry, CV. (:. rr11d JJttt~l~n, H. M. (I!l(j(i). Vertlcnl ~ n ~ g r a t l oa n d drstnbution of ~~~onopoltrgic tisl1c3s off Orc4~c)orr. Ikep-~SeuHeseurch, 13, 153 165. tl 1,. I?. (I!l(iH). Eftcfcts of pntssrtre o n tllr respirntiol~ l3t~crrcy,\\'. G . r ~ r ~ SrnnII. of vctrtlc.tllly lurgrat~tlg cruatwc-(~IIIS.elo~rrnalof the li'i-~herie,~Research Honrtl r?fCattcda, 25, 1311 1416. 1'erc.yr.a~. CV.,.'l' l'octrc:y, W. a. a ~ l t ('ul.\ l csy, 1"..:F .I r ( 1 96!)). rS'chfl.utr~rle.9JIIVZ~UR, r l drc.lf rockfish f t ~ t ~ d on i ~ r ~nt~uol)t*l~lplc ~ ~ I ~ I I I IWI I ~, I Ia corrh~d~ratiori (~f' c~i.ctlogrc.nl rrny)lrcwtio~ls. Jmrrr~talq/ the I'ixh~riesResearch Noard rf Canaclo, 26, 2211 2215. utrr It1 rnor[)Irolog~c.et la crotssnrree cllrz 11t genre. t t ~ I t . ( 7 ) 1101111cicv 1,trc.ifrt. (1)c-c-npodcsStargc-atrdtict): I,. intemedic~a,1,. peniczlliJlr, I,. hanxe~c?, L. clrcwei. 1,. fa.roni. Cal~isrO.l?.S.I'.O.dl. S6r. OcCar~oyraphyrre,11, 207 227. o , I. ' ( I ! ) A rlcrw spcbc.~t~s of ~ l ~ r ~ r Aceles r ~ p , cochinsnuw (C'~IIH~IL(Y-II, W C ~ of H ~ I n d t r ~w~t,ha11 rircour~tof L)c.cctyoclrc, Sc>rpwtidac.)fro111 ~ ~ O I I ~ ~ I -coast ~ t n111rvnI clc~celop~nor~t. J o ~ r r n n lof the Marine Hioloqkul A ~ H o ~ i a t z o n(4 Intliu. 10, 2!)$ 320. I t a y ~ n o ~# ~ , (i., Au\tln, . I . nrltl I.tl~forcl, .:b (196'7). B~ocflc.rn~c.ul I . tLC. r.orn11onrtlor1 of c-c~rtrc~n octbtlnlc tlecapodr. 1)ecp-Sea Research, 14, 113- 115. I
I~udjrakov., I . A . ( 1970). ‘l’lir posxibIi+ CIIIIHO of d i d vertical inigrntioti of plaiikt o i i i c - iiiii~iiiilx. Alariice 7jio/o!/y, 6, !)8 105. Sivwtxoii. E. t i i i d HoltJiiiis, 1,. t3. (l!l56). Criisliicoa Dectipoda (tlit, Pvriwidra nnti Stcviopodidrx~oxetytrtl). IZeport or) tlceScientific Readt.4 of the “ Afichael Sarx ” North Atlantic I)eep-kSr(i Ex/ieiliti~in,5, (12), 1 64, plotcw I 4. Stnil ti, 1’. 14’. (1!)54). 1’11rt1i(*riii(i~i~iiri.i~ic,iils of ttho sorind ~cuttc~riiip pvqwrtion of so\ cwil i i i i i r i r i o ~ P ~ I L I I I H I ~ H1)ecp-h’ea . Heuearrk, 2, 71 79. Siriitli. S. I . ( 1884). l{q)ori o n tliv docwpnd (‘rusttloon of tho A11,ritrtas drodgirigti o f l tJiv ocixf comt of tlio Utiifotl S t d w i t i 1883. Report of the U.S. C o w vniwrrioitcr of k‘id&eriew,10, 345 42U. 8oojiinn, I . ( I ! W i ) . [On tlin drvc4opiiiont and cwdogy of Acetea japoniczta ICislii~ioiiy(~ I I I tliu Arinkn Soti.] ~SirixanGakbuai Ho,4, 153- 1113, plate 4. (111 Jo~MuI(w(*.) Sttwlo, 1). H. (l!).57). ‘l’h rodfisli (Sthadex ittarinwe L.) i n tho aostorn Gulf of St. I A c i w i * ~ ~ ~Journal ie~~. of the fi’idmries lCe8earch Board of C a d , 14, 899024.

~ ~ q d i l ~ i I H O i I<. 1,

(I!)%). 1)ocRpodn-Muc.riirn ~ x c l .8orgrHtidnc. Report of the ltir to the Medibrrnean, 2, D3, 1- 85. Danish O c r c ~ i i c ~ ~ m pExpedition Sttyliottxc.tt, I<. ( 1935). ‘rlw Godttiniil) Kxporlttion 1928. Cnistmxa Deuapoda. Mechirlelrrcr orn (hnland, 80, ( l ) , I -!+4. S w d . 0.(1!+12). ‘ I ’ h gltisx shrimps (Pasiphaea) in thn northern wthtws. Bergenv ttw.veti)tt8 rirbo!/ 1!)12, ( G ) , I 18, plat()# 1 3. Sunci, 0 . (1!+20). P‘cncidw mid Stoiiopidox from tho “ Michael 8;iltrw” North Atlmitir I~oc~p-Son Expnditioii 1910. Report on the Scient@c Remdts of the “ Mirhnrl S ( w x ” North Atlantic Derp-Sea Expedition, 3. (2), 1-36, platos 1 niid 2. Siiyoliiro, Y. (1!)42). A ntuily on tlin dipxtivo systrmi and feeclirig habits of fish. .lapaneee ,lotrmnl of Zoology, 10, 1 303, pintos 1 15. ‘I‘rtnnkn, T. n ~ i d~aiisiidq. Deep-Sea Research, 14, 725 -733. ‘I’tvno, A. ( 1!)17). Notox o i i tho pliotop1iort.a of Sergerrteg prehensilie Bate. Annotatiortrx zoolo!~wnejuponewea. 9, 29!)-3 16. Tiitciri, A. K.(1!)50). The fooil and fwding ri*It~tionnlirps of tho fin11c.s of Singapore St rnitn. /“i;ulter?/J’tthlitatione, Colonial Ofice, 1, 1 -3.5. T1i;iltin. A. K. (195.5). ’1’11~xlirimp industry of Singapore. I’roceedinyx of the 5th Ititlo- I’rrrqic Fiwlteries Council, h‘pctions 2 and 3, 145 152. Tlioiiipsc~ii..J. 13. ( 19N). (‘ornincntx on pl-iylogony of mction Coridoe (Docapoda, h’atentia) firid tlie pliylogmctic importance of the Oplophoridea. Procrerling.9 of the Symposiltm on Crustacea, 1, 3 14-326. Tucker, G. H. (3951). Relation of fishes and other organisms to tho scattering of rititl~~rwntc~ xoirrid. .Journal of Marine Research, 10, 215-238. Viiingrdov. M. 15. ( 106 I ) . Veediiig of tlie deop-sea zooplankton. Rapport et I’roriz.4- iwrhair.c (lea Ititmiom. C:onseil permunent intcrnatwnal pour I’ Erplumtion de la mer, 153, 114-120.

324

MAKOTO OMORI

Vinogradov, M. E. (lQU8)." Vertical nistrihution of the Oceanic Zooplankton". Pirblisliicig Hoics(*'* Naiika MORWW.( I n Itusaiaii.) VOSS,a. 1,. ( 1 !No). The polegic niid-wrttero fiiiina of the eastern tropical Atlantic, witlr specid refemnco to t f i c ) Gulf of Guinea. UNESCO/FAO/OAU Procoodiiiga of the Symposium o r i tho Ocmnography and Fisheries Hesources of tho Tropical Atlantic, Abidjan, 1906,pp. 91-99. Unosco. Wassurloos. E. (1908). Znr Konritnis dor Motaxnorphose von Sergestea arcticwr Kr. Zoologi.9eher Anzeiger, 33, 303 331. Watermazi, T. H., Nunnomacher, It. P.,Chace, F.A. J r and Clarke, G. L. (1939). Diitrrial wrtical migrations of doop-water plankton. Biological Bunetin of the Marine Rkdogical Laboratory, Woods Hole, 76, 260-279. Welsh, J . H. and Chaco, V . A. Jr (1937). Eyes of deep-sea crustaceans. 1. Acaiitliepliyridao. Biological Bulletin of the Man'ne Biological Laboratgy, Woods Hole, 72, 67-74. Welsh, J . H. arid Chace, F, A. Jr (1938). Eyes of deep-sea crustaceans. 11. Sergestidm, niological Bulletin of the Marine Biological Laboratory, Woods Hole, 74, 364 -376. Williams, A. B. (1965). Marino decapod crustaceans of the Carolinas. F h h e y Bdletin of the C J . R . Fish and Wild1;fe Service, 65, 1-298. \Villiamaon, D. I. (1900). Larval stages of PQsiphQca eivado and some other Pasiphaeidae (Decapoda). Crwtaeeana, 1, 331-341. Williamson, D.I. (1969). Names of larvae in the Decapoda and Euphausiacea. Cmtaceuna, 16, 210-213. Williamson, D. I. (1973). -4mphionides reynadii (H. Milne Edwards), reprewntative of a proposed new order of eucaridan Mrtlacostraca. Cmtaceuna,

".

25, 36-50.

Wollobaek, A. (1908). Remarks on decapod crustaceans of the North Atlantic and the Norwegian fiords. Bergem Muaeums h b o g 1908,(12),1-77, plates 1-13. Woodmansee, R. A. (1966). Daily vertical migration of Lucyer, planktonic numbers in relation to solar and tidal cycles. Ecology, 47, 847-850. Yaldwyn. .J. C. (1967). Deepwater Crustacea of the genus SergesteR (Decapoda: Natantia) fiwm Cook Strait, New Zealmd. Zoological PublicatWna from l'ictoria University of Wellington, (22),1-27. Ymuda, J. (1957). [Riologioal studit% of shrimps in the littoral region.] In " Suis~npaku-shusei " ( Y .Suyehiro et al., eds.), pp. 171-198. University of Tokyo Prew, Tokyo. (In Japanese.) Ymiida. J., Takamori, S. and Nishina, S.(1963). Study on the ecology of Akiami (Acetesjaponioue Kishinouye) and its multiplication end protection. Bulletin of the h'aikai Regional Fisheries Reaearch Laboratmy, (4), 1-19, (In Japanem) Yonge, C. M. (1955). Egg attachment in Cranqon uu.lgari.9 and other Caridpa. Proceedings of the Royal Society of Edinburgh, (B),85, 309-400. Yodiida, H. (1941).'Important marine shrimps and lobsters of Tyosen (Korea). Bu1lelin of the Fisheries‘ Experimental Station, Fuaam, (7),1-36, plates 1-1 3. (In Japanese.) Yoshida, H. (1949)., On the life-history of Acetea japonkw Kishinouye. .Journal of the Xh&ao9ao8t!ki College of Fbherie8, 1/2,51-56. (In Japanese.) Z h m e m a n , S. T. (1973). The transformation of energy by Lucifer c k e i (Crustacea, Docapode). Pacific Science, 27, 247-259.