PFOc: EINGS F THE WORLD SCIENTIFIC CONFERENCE. Mexico City, Mexico, June Ciudad de México, México, junio 1967

Transcription

1 Fsheres Re fi orts No. 57, VoL 4 PFOc: EINGS F THE WORLD SCIENTIFIC CONFERENCE ON THE PIOLOGY AN CULTURE OF SHRIMPS AND PRAWNS ACTES D LA CONFERENCE SCIENTIFIQUE MONDIALE SUR LA BIOLOGIE ET L'ÉLEVAGE DES CREVETTES ACTAS DE LA CONFERENCIA CIENTIFICA MUNDIAL SOBRE OLOGIA Y CULTWO DE CAMARONES Y GAMBAS Mexco Cty, Mexco, 2-2 June 967 Mexco (Mexque), 2-2 jun 967 Cudad de Méxco, Méxco, 2-2 juno 967 FRm/R57.4 (Tr) j V A F ? FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS ORGANISATION DES NATIONS UNIES POUR L'ALIMENTATION ET L'AGRICULTURE ORGANIZACION DE LAS NACIONES UNIDAS PARA LA AGRICULTURA Y LA ALIMENTACION ROME, 970

2 FAO LIBRARY AN: 007 FRxn/596 FAO Faheres Synopsa No.96 SÄST - Prawn SYNOPSIS OF BIOLOGICAL DATA ON THE PENAEID PRAWN Solenocera ndca Nataraj, 945 E:pos synoptclue sur la bologe de Solenocera ndca Nataraj, 945 Snopss sobro la bología de Solenocera ndca Nataraj, 945 Prepared by M MYDEEN KUNJU Central Marne Fsheres Research Insttute / Mandapam Camp, Inda / Present address: Central Marne Fsheres Resoaroh Substaton, West Hll, Calcut-5, Kerala, Inda

3 FRm/596 S. ndca IDENTITY. Taxonomy., Defnton,,2 Descrpton,2 Nomenclature 39 CONTENTS / t Fafs No, I 3.2, Vald scentfc names.2.2 Synonyme,2.3 Standard common names, vernacular names * 3 3,3 General varabt * 2 DISTRIBUTION.3. Subspeofo fragmentaton (races, varetes, hybrds)*,3.2 Genetc data (chromosome number, proten speofcty)* 2, Delmtaton of the total area of dstrbut Loa and ecologcal charaoterzaton of ths area 2,2 Dfferental dstrbuton 2: 2.2. Areas occuped by eggs, larvae and other junor stages: annual varatons n these patterns, and seasonal varatons for stages persstng over two or more seasons 2,2,2 Areas occuped by adult stages: seasnal and annual varatons of these 2.3 Behavoursto and ecologcal determnants,f the eneral lmts of dstrbuton and of the varatons of thse lmts and of dfferental dstrbuton * 3 BIONO4ICS AND LIFE HISTORY 3, Reproducton 3 3., Sexualty (hermaphrodtsm, heterosexualty, ntersexualty) I 3..2 Maturty (age and sze) 3.,3 Matng (monogamous, polygamous, promscuous) 3,.4 Fertlzaton (nternal, external) 3.,5 Fecundty 3,,6 Spawnng 3.,7 Spawnng grounds 3,.8 Egg structure, mze, hatchng type, parastes, and predators 3.2 Larval hs2 3,2, Acoount o embryonc and juvenle lfe (prelarva, larva, postlarva, juvenle) / Ths synopss ha been prepared accordng to Outlne Verson No. (H, Rosa, Jr., FAO Fìsh, Synops., () Rev.l, 965).

4 FRm/S96 S. ndca 3,3 Adult hsz 3, Longevty Hardnoss' Compettors a 3.3,4 Predators * 3,3,5 Parastes and dseasen 3 3,3.6 Greatest sze 3 3,4 Nutrton and growth 3,4.. Feedng (tme, place, manner, season) * 3.4,2 Food (type, volume) Relatve and absolute growth patterns and rates 3,4,4 Relaton of growth to feedng, to other aotvtee, and, to envronmental faotore * 3,5 Behavour 3.5, Mgraton and bon movements Schoolng * 3,5,3 Reproductve habts * 4 POPULATION (STocK) 4, Structure 4,. Sex rato 4.,2 Age componton 4..3 Sze composton Sze and donst,y* 4.2. Average sze Changes n sze 4.2,3 Average densty Changes n densty 4,3 Natalt and reorutnent * 4,3. Natalty Natalty rates 4.4 Mortalty, morbdty M 4.4. Rates of mortalty Factors or condtons affeotng mortalty Faotors or condtons affectng morbdty 4.4,4 Relaton of morbdty to mortalty raten 4,5 Dynamcs of populaton * 4.6 Relaton of populaton to communty and eoosyetem, bobooa produoton, etc, 3* EXPLOITATION 5, Fnhng equpment 5,, Fnhng gear 5..2 Fnhíng boats

5 WRm/596 S'. ndce 52 Fnhnj areas 5.2, General geographc detrbuton Oeographcal rangen (:ìattndes, lstanoes from ooat, eto.)e Depth ranges 5,3 Fshrq seasons 5.3. General pattern of fshng season 5,3.2 Duraton of fshng season Dates of begnnng, peak and end of season 5,3.4 Varaton n tme or duraton of f mhng season * 5,3.5 Faotoro affeotng fshng season 5d 5.4 Fshng operatons and results * 5.4. lcffort and ntensty * Selsotvty 5,4.3 Catohos 5,5 Fsheres management and regulatons 5,6 Fsh farmn trans.antn and other nterventon e 6 REFERINCES 6, As no nformaton was avalable to the author, those tems have been omtted from the tez

6 - 322 FRm/296 S,ndloa, 'IDENTITY lo Taxonomy,,). Defnton Phylum Arthropod.a Class Crustacea Subclass Malacostraon Seres Eumalacostraca Superorder Euoar Ord.er Decapoda Suborder Natanta Secton Penaoldea Famly Penas das Subfamly Solen000rnae Genus Solerocera Lucas 850 Speces Solenocera ndca Nataraj 945 Generc..2 Descrpton Solenocera Lucas, : 300, Type speces, sphonoceros Phlpp branaceue lusso, 865 Placed on the Offcal n Zoology as Name no. 849, Rev.Mag.Zool.(2) by monotypy: Peneus 840 (Penaeus men- Gender: femnne, Lst of Generc Names 444. The followng descrpton s adapted from Kubo (949), Rostrum short and serrated dorsally0 Carvcal and hopatc groove well defned, Antenral, post-orbtal and hepato spnes always present, but branohostegal and pterygostoman spnse may or may not be present0 Abdomen dorsally carnated, Antennular flagella folaceous, longer than carapace; upper flagellum rather flat, narrower than lower ramus; lower flagellum oonoavo-oonvex, wth convex surface outward, Mandbular pap two-segmented, dstal jont trangular, rounded at the apex. Maxllary pap rot jonted. Maxlla wth uneegmented endopoc, Frst ma.xllpod wth slender 5- jonted palp, Seoond maxllped nverted J- shaped, consstng of 7 segments, Thrd maxllped. ped.form, consstng of 7 segments, no sexually dmorph&o. Exopods present on all thoraoo appendages. Petasma bearng a par of epatulato projectons on ventral free edges, and wth many setas on dstal borders0 Appendx masculna wth proxmal part havng a spur-lke outgrowth on nner surface; dstal part composed of 2 scale-lke appendages. Thelycum smple, A pleurobrancha on thoracc somtes from 3rd to last (8th), A par of' orthrobranchae on anteror 7 thoraoc aomtee, A podobrancha on 2nd maxllped, Mamtgobranohae present on all maxllpeds and anteror pereopode. Kubo (949) frst employed the stomodeal ossolos n deoapod taxonomy, In terms of hs nomenclature, Solenocera has the oardao plate wth many spnules aranged n a longtudnal seres on the nner surface, ptsrooarcl.ao dchotomous at outer end; zygocardao wth teeth gradually decreasng posterorly; px'epyloro provded wth many ponted teeth along each postero-lateral border. Parasolenooera Wood-Mason, In Wood-Mason and Al000k, 89, type speoes Parasolenocora annectens Wood-Mason, 89, s here regazj as a junor subjectve synonym of Solenoc 3- LUCam. not Specfc Solenooera ndca Nataraj, l94, The whereabouts of the type raomon s Typo localty: y of Bengal. Carapace smooth ard glabrou, Rostrum straght, lanceolate, slghtly asoendng, reaohng to tp of basal segment of antennular peduncle; armed wth 9 to 0 teeth on upper margn, becomng smaller and more closely spaced towards the front, nterval between st and 2nd twce that between 3rd and 4th; tomentum on sdes of rostrum very feeble., Post-rostral oarna feeble, becomng dstnct towards posteror regon of carapace, Orbtal anglo dentf ors, Post-orbtal, antennal and hepatc spnes small, thn and sharp, No branchoe-tegal or pterygostoma,n spne. Cervcal groove oblque, deep and broad on sdes, contnuous wth that on the other sde through very fant notch on post-rostral carna; contnues oblquely downwards below hepato spne towards antero-nferox' angle of carapace. Another groove orgnates from level 0±' hepatc spne, runs upwards to fade before reachng base of post-orbtal spne, Cervcal groove runs horzontally backwards from baes of hepatc spne then turns oblquely downwards towards ventral margn of oarapaoe branchostogal sulcus orgnates from angle of nfero-. lateral curve and runs backwards towards poe.- tenor border of' carapace, Fourth, 5th and 6th and posteror half of 3rd abdomnal segments sharply oarnated dorsally; carna of 6th segment termnates n spne. A medan sternal spne between basee of each pleopod par, spnes decreasng from anteror to posteror, Telson deeply sulcate md-dorsally on anteror two-thrds; lateral margns devod of spnse; tp of' telson ponted and shorter than exopod. of uropod,

7 FRn/596 S, ndca Fg. Solønooera ndca Nataraj 945.(after Kubo, 949)

8 FRm/59b S. ndca Antennular pedunclm slghtly less than half length of carapace ncludng rostrum, shorter than antenna]. scale; basal segment ot odunole as long as 2 dstal emonte combned, uounuar flagella each slghtly longer -tha? earapaoe ncludng rostrum; nferor flagellum uco as wde as superor flagellum, flandbu].ar pap 2-jonted, basal jont La-ular, as long as dstal wdth; dsta]. jont narrow, slghtly less than twce as long as basal segment, Thrd maxllped reaches tp of antenna]. scalo; oxopod reaches mddle of sohum, lechus of le and bass of let and 2nd ohelpeds armed on nner sdos wth spnes. All legs wth slender exopots whoh gradually become smaller posterorly, Second obelped reaches level of tp of antenna]. scale; 3rd (longest) oholped. reaohes level of mddle of antemule. Ffth leg s the thnnest, reaches about to mddle of antennulos. The 2 halves of potassa unted anterorly; eaah half of 4 lobes fused together posterorly and free a dstal margne. Inner lobe s longest, has tp swollen nto spongy mass wth toothless outer margn; next lobe wth angular border, dstal porton frnged wth row of recurved spnes, hard ohtnoun angular plate projectng from near tp; 3rd lobe wth broadly rounded outer border frnged row of small recurved spnes, small concal plate projects from nner sde; 4th lobe les nsde 3rd., thokened groular dstal end curves outwards. Thelyoum conssts of: hard plate protrudng from sternum behnd 5th par of legs wth tuberoulous projecton between basse of legs, par of closely approxmated. small knobs orgnatng from sternum between 4th and 5th par' of legs, hard vertcal plato between bases o 4th par of legs, small nner lobe on coxa cf 3rd loge Proxmal part of appendx masculna wth bar-shaped projecton on nner eu.cfaoe, convex at apex, drected ventro-laterally; rdge-lke elevaton on anteror surface, Cardac plats armed on nner surface wth about 6 ponted spnules arran;d n longtudnal seres, Cardac oss&cl euboval, Perocadac ossdo bar-shaped; anterc-medan angle produced and ponted, postero-medan angle broadly rounded. Prezygcoardao csolo mnute, and subreotangular. Urocardao ossdo wth trangular anteror dlaton; anteror pont blunt, lateral ponts sharp. Anteror edge of zygocardac wth 2 large sharp oonoal teeth, row cf acute long teeth just above upper large tooth, Prepylorc wth about 0 slender aoue teeth on enoh postero-lateral edge. No tooth near anteror end of nner nternal wall of pyloro chamber ( tooth n other speces) (Pg. ),,2 Nomenclature.2. Vald eoentfo r Solnocera ndca Nataraj, 945, Journ. Asat.Soo. Bengal ()t94. In the orgnal publcaton the specfc name was spelled "ndcu&', but snce the gender cf the generlo name Solen000ra s femnne, t has been changed to ndca,.2.2 Synonyms Objectve synonyms None Subjectve eynonylns Solenocera subnuda Kubo, 9499 J.Pckyo Coll.Fsh. 36(). Solencoera kubo Ea Mus,, , Bul.Raffl' Phs s one cf the moro than 25 descrbed speces n the genus Solenoosra and seems most closely related to S. promnente Kubo and oramscorne (H, Mlne Edwarde). Wthn the last 25 years t has three tmes been descrbed as new, frst by Nataraj (945), then by Kubo (949), who evdently was not ewars of Nataraj's publcaton and then by Hall (956) who at frat thought hs Sngapore materal to dffer epeofcally from Kubo's speces, but later eynonymzed the two forms, Hall (962) stated that spnes on the lateral margn of the telson are.present n some juvenles. Ths fndng e sgnfcant snce the man dagnostc oharactere cf S. ndca are the absence of telson spnes and the absence of branchostegal and pterygoetoman spnes..2.3 Standard common names, vernacular names None reported..3 General varablty.3. Suhspocf&c fragmentaton No subspeces are recognzed. 3

9 FRm/ ndca 2 DISTRThIJPION 2. Delmtaton of the total area of datrbuton and ecologcal charaotsrjzmtjo of ths area In Inda the speoes s found all along the west and east ooasts, Ahmad (957) am Nataraj (945) recorded t from East Pakstan, The materal from whch the orgnal doecrpton was made was partly obtaned from the Mergu Archpelage and Sngapore, lleoontly Ball (956, 962) reported tke specem from the west coast of Malaysa (Penang and Sngapore); ICubo (949) recorded t from (ortl Borneo and Cheung (960, 963) from around Bong Kong. In termu of the FAO areas code (see Eolthus and Rosa, 965) t s recorded from parts of sea areas 6W and IslN, and from the coasts of land areas 423, 425, 433, 436 and 422. Whle the majorty of the speces of Solenocernac are deep esa forms, S. ndca s defntely a lttoral speces, nhabtng waters of 40 a and loss, where there s a lkelhood of small seasonal fluctuatons n temperature and sal ru ty, Around Bong Kong the larvae occurred moat abundantly» the months of May to July and wore absent n the wnter months These larvae 000urred. most abundantly n areas where mxed marne and ostuarne condtons preval, and durng the warmest and most rany season, when the salnty n Hong Kong terrtoral waters was at ts lowest (Cheung, 959), I seems probable then, that a relatvely hgh temperature and low salnty are favourable condttoam durng th mpamng season of the speojes o whoh these larvae belong9 22,2 Areas 000uped by adult stages: seasonal and annual varatons of theme Adults and larvae oocur together, wthn the 40 m depth oontour, Females mgrate to the doeper parts of the area to spawn (seo sootona 3.,6, 3..7), but the maleo reman n the shallower areas. 2.2 Dfferental dstrbton 2.2. Areas occuped by eggs, larvae and other junor stages: annual varatons n those patterns, and seasonal varaton for stages persstng over two or more seasons Cheung (963) dentfed protczoeal and zoeal stages of S. ndca frocs plankton olleoted near Bong Kong at the surface and at a deptb of 6 m. lo naupl were found, but as the later larval stages wore found together wth mature and spent females, t s unlkely that the nauplar stages dd not exst n the same localtes.

10 FR/s96 S. ndca BIONOMICS AND LIFE HISTORY 3. Reproducton 3.. Sexualty (hermaphrodtsm,. hoterosoxualty, ntersexual ty) S, ndca s heterosexual. The males are oonserably smaller than the females Maturty (age and sze) Kunju (968), tn hs study of the prawn from Bombay, estmated that the ovary begns to mature n females of 5 mm n length and of age 5 to 6 mo, Snos the mmature ovary takes about 3 mo to attan the spawnng stage, the prawn may spawn for the frst tme when t s 8 to 9 mo old, rpj0 malo attans sexual maturty at a length o about 50 mm, 3,,3 Matng (monogamous, polygamous, promsouous) No observatons have been made on sexual behavour, but the speoes s expeoted. to bo promscuous, Matng takes pnos n the shallower areas of the habtat, 3,,4 Fertlzaton (nternal, external) Fertlzaton s external9 as n other prawns, 3.,5 Fecundty Females measurng 25 to 28 mm (carapace lengh) were found to have,36 x 0 to,58 z 0 eggs n ther ovary (Cheung, 963), 3.,6 Spawnng Kunju ( 968) found that on the Malnraehtra coast of Inda the prawn spawns from October to May wth 2 spawnng peaks n De-. oember ar.d Aprl, Cheung (963) also observed 2 peak spawnng perods n Hong Kong waters, the let from November to December and the 2nd durng August and September, He, however, found no spauang from January to May, 3,.7 Spawnng grounds Kunju (968) found Ghat the man spawnng ground s just outsde the fshng grounds on the Maharashtra coast, These grounds are all wthn 40 m. On the observed fshng grounds a defnte pattern of spawnng mgraton woe recognzed, wth the fully mature females movng offshore. Ne has adduced evdence that these spawners do not go far out, but they lberate the eggs near the 40 m depth contour. Smlar fndngs wore recorded by Cheung (963) n the Hong Kong area, 3,,8 Egg: structure, sze, parastes and predators Fertlzed eggs of S, ndca have not been dentfed from plankton collectons. The dameter of an ovaran egg was found to be 0,7 to 0,25 mm, Kunju (968) occgnzod the followng stages of maturty n ovaran eggs: Immature: Ovum transluoent, nucleus clearly vsble, yolk granules sparsely dstrbuted, Maturng-early; Nucleus fantly vsble through yolk granules, Maturng-late: Ovum opaque, packed wth yolk granules; nucleus not vsble, Maturo: Surface of ovum appears oorrugated due to presenoe of rod-shaped perpheral bodes, 3.2 Larval hìst,or 3.2, Account of embryono and juvenle lfe (prelarva, larva, postlarva, juvenle) Cheung (963) descrbed the protozoene and moans of S, ndca, No nauplar stages nor postlarvae (mmedately succeedng the odest zoeal stage) wore found, Protozooa: Two substages of the 3rd. protooer wore recorded, Earler dffers from laker n rato of lengths of log rudments and uropode to body length, Telson of earler protozoon wth shorter uropode, Carapace of earler substage measures 0,97 to.7 nun, wth several large spnes. Rostrum and supra-orbtal spnes eaoh bear a few spnues, other spnes smooth, Surface of entre oarapaoe oovered wth very mnute spnules, Margn of carapace frnged wth 5 pars of lappets, serrated between st and 2nd and between 3rd. and. 4th, Dorsal organ (on anteror medan part of cara-. pace) large; small unpared paplla near posteror border of carapace, None of thoraoo segments fused wth carapace n ether substage. Each abdomnal tergun wth one dorsal and par of lateral spnes, Telson bfuroate posterorly, each half wth 7 sotae, Uropode loss well developed n earler than n older substage; endopod wth 3, exopod wth 6, termnal setae n each substage. Antennule 5-segmented wth 5 termnal setae. Exopod of antenna 9-segmented; endopod 4-segmented, wth 6 termnal sotas. Mandble wthout palp, Functonal natatory exopods on mt and 2nd maxllpods, Thoraoo legs

11 r 2. nd Pg ncuoa, 3rd protozoea (ftor Cbeung 963). (k) to (L) older eubst s (A) Carapoo, dorsal vew. (B) Telson and uropode, (C) Antennulo, (D) Antenna. (E) Mandble F 4axllule. (o) aa, (H) let mazlpd. J 2nd maxllpod. (K) 3rd. maxllpedo (L) Pereopod. M Younger substage; Telson.

12 FBm/596 S. ndca rudmentary, endopod much shorter than oxopod, Ploopods not yet developed (Fg, 2), Zoco. ()j Four zomal stages have been din n8lshod by Cheung (963), The 2nd. and. 3ro uagcs nro ntermedate between the 2 stegen desorbod hors, Frst zosal etage: Carapaoo.37 to,59 mm; no epnules on surface of carapace, no lappete; small spnes near serrated lateral ma'- gfla; dorsal organ reduced; carapace fused wth ll Uoraoo tergtes. Spnes on abdomnal terga as n protozoea, but lateral spnes muoh smeller and 2nd dorsal spne largest. Telson deeply forked, 4 sotae on each nner margn of each prong, par of small spnes on outer margns proxmal to fork. Uropode well developed, nuxneroue long eetae on each margn of andopod and on nner margn of' oxopoc, Inner f alum of antennule wth 2 termnal setae; outer fagelurn slghtly longer, wth 4 setae, Endopod of entonna shorter than scale-lke exopod; exopod rh spne on dstal '3 of outer margn, NancUblçj wth small pap, Frst 3 peroopods chelate; all pereopode wth natatory exopods, Fourth (last) zosal stage: Carapace.9 to 2,24 mm; dorsal organ and spnes relatvely short, Narrowly forked telson wth 4 pars of spnes wthn the fork, Exopod and. endopod of ux'opoct rather broader than n st zoea, ulth more Botae. Antennule wth muoh longer flagella. Flagellum of antenna far exceeds scale; scale long, slender, wth short subtermnal spne on external margn. Mandbular pap long-. er and narrower; oxopod of 3rd maxllped much reduced, Pereopods very smlar n all zoea3. stages. Pleopode wel) developed, bramous, (Fg. 3). 3.3 Adult hstory 3.3. Longevty On the bass of' overa growth rs.te of' juvenles and adults and maxmum recorded sze, the estmated lfe span of the female s 4 to 5 mo and that of male 9 to 0 mo (Kunju, 968). Cheung (963) s of the vew that the prawn lves for consderably less than 2 yr. 3,3,5 Parastes and dseases Bopyrd parastes are frequently found n the gl) chambers of' penneds n general, but no nstance of stch parastsm ham been observed n S. ndca, 3.3,6 Greatest sze The largest male ard female recorded from Hong Kong (Cheung, 963) had total lengths of 30 ard 6 sm reapootjvely, 3,4 Nutrton and, growth 3.4,2 Food (type, volume) The stomach contents of 0 specmens from Hone Kcag, examned. by Cheung (963), contaned daoms, emal gastropods, emal bvalves, o opepode and. other small crustaceans. Hal (962) analyzed the stomach contents n detal and proved that polyohaotes are the domnant food n Malaysan waters. Kunj.0 (968) studed 46 females and 80 males of varous mzo groups fren the west coast of Inda; the stomach oontents, n ther order of abundance, were crustaceans (Deonpoda Copepoda and others) (44.69 percent), debrs percent), fsh (22.2 peroont), poyohaotee (2.96 percent), molluscs (.96 percent), sand grans (.95 percent) and moeaneoue tems (0,53 percent), Relatve and absolute growth patterns and rates Choung (963) stated that no growth takes place n the wnter months n Hong Kong. The resumpton cf growth from February through March to Aprl corresponds to the rse n water temperature n sprng, In May, however, no growth can be detected for the males, and a regresson s found n the females, Ths assocated wth a remarkable rse n the proporton of the females, tn June, regresson of sze takes place n both sexos, am ths mght be due to the movement of the larger prawns away from the area, or movement of' rmaer prawns nto the area, or both,' Ths decrease n average sze of the populaton s assocated wth the lowerng of the anty caused by the outflow from the nearby Pearl <v-er and wth the summer rce n temperature, Cheung also stated that the young generaton chov rapd grcq-th from July 'to Deoember. Smaller prawno appear n the oabohes n November and. December and mght represent another recrutment due to a second. smaller spaunng n the autumn, Kun,ju (968) studed the growth of the prawn from catch samples collected over a long perod n Bombay. From sevoral seren of progresson of modes, the average growth rates were estmated, The average groeth per month n prawns of over 33 mm was 6,96 mm for females and mm for males, Recrutment of juvenles of both the sexes, measurng less than 33 mm, was evdent n the months cf January to Marob every year. They were probably the progeny of the major spawnng group of' November to Deoember and would therefore be 2 to 3 mo old when sampled, It therefore appears that young prawns grow at a faster rate than those of mere than 33 mm n length,

13 34 /96 s. doa E E Fg, 3 3, ndca, zoeal stages (after Cheung, 963), (A) o (K) Frst stage: (A) Carapace. (B) Telson and uropocìs, (C) Antannule. (D) Antenna. (E) Mandble. (F) to (K) l4axllule to 3rd majllped. (t) to (u) 4th otages Ç t) Carapace, dorsal vew. (M) Telson and uropode. (N) Antennule. (o) Antenna. () to (u) Mandble to

14 FRm/696 S. ndos 3:5 3,5 Behavour 35. Mgraton and local movement In Bombay, Kunju (968) found 2 types of mgratory movement n S. ndca, ono n oonnecton wth spawnng and the other n relaton to salnty0 The females move out of the fsh- Ing grounds for spawnn but the males reman. The gradual deóraase n -the number of prawns n advanced stages of maturty could be due to such a movement0 Ths lmted spawnng mgraton was found to take place throughout the year, wth peak perods n December and Aprl0 The populaton en masse moves offshore when the salnty of the coastal waters decreases from June to early October, as a result of the southwest monsoon rans, There s evdence to show that, as n the spawnng mgraton, the prawns do not move far beyond the 40 m depth cent our Cheung (963) found that the prawn n Hong Kong waters does not show marked mgratory behavour such as was found n Penaeus orentals 'by Lu (955). Wthn the general envronment of the prawn, however, small scalo movo»cnts do take place for varous reasons. There s no drect evdence of a mgratou nto offshore waters for spawnng n the summer, but length frequenoes ndcate that no growth takes place from Aprl to May and regresson of sze appears to take placo from May to June, Ths may be due to mgraton. A comparson of the catches of the prawn n -the 4 areas studed around Hong Kong shows some ndcatons of mgraton, Thus, n areas where there s some freshwater nfluence there were decreases n the catches from Aprl to Juno; on the other hand there were ncreases n the catches n the marne localtes n Aprl and June, but not n May, It may be that mgraton took placo from -the eatuarne areas to the offshore areas when the adults were maturng, At ths tme of the year, -the outflow of the Pearl Rver lowers the salnty of the adjacent areas; whether or not ths has drect effect on mgraton s net known. Choung further stated that the decrease n catches n May n the marne areas mght possbly be due to the death of some recently spawned adults, as well as to the mgraton of others away from the sampled areas.

15 - 33 FRm/S96 S. ndoa 4: 4 POPULATION (stock) 4. Stx'uoture 4.. Sex rato The female to male rato n the populaton of S, ndca n Bombay waters vared from month to month but there were al%lays more females than males, The dsparty between the sexes was least n October and greatest n January, Aprl and Llay, when moro than 2/3 of the populaton was composed of females, Over the entre perod of nvestgaton, there were twce as many females as males (Kunju, 968). 4.,2 A composton In hs nvestgatons conducted around Hong Kong, Cheung (963) stated that, anoa the lte span of the speoes s less than 2 yrg the populaton could oontan 2 year classes at most, 4,,3 Sze composton Cheung (963) used the carapace length for length-froquenoy studes and found the relatonshp btween carapace length and total length to be as follows: Smaller szes were poorly represented n hs samples because these prawns escape more easly through the net. Small malee, th a modal carapace length of 5 mm, entered the fshery n July, After reaohng the 8 mm mode n November, there îao a paume n growth, so that from December o February the populaton stayed at the 9 mm mode, The domnant ss group from March to July had a modal length of 20 mm, Young females of 6 to 0 mm oarapaoe length domnated the populaton n July, and grow to 30 mm by Deoember, thon there was lttle further growth durng January and February, From March to July females of 24 to 29 mm oars-- pace length ocourred, Kunju (968) studed the length frequency dstrbuton of ndca n Bombay waters, usng the total length from tp of rostrum to tp of telson, In contrast to Choung (963), nets wth small-meshed oocl ends poro used, so that the small prawns would be e4oquately sampled. About half the female opulaton was between 56 am 80 mm, am about 34 peroont of malos was between 5 am 60 mm, The o dstrbuton var.ed from month to month n both sexes, L ,26 C where L s the total length and C the oarapaoe length n orn,

16 'rm/s96 5. ndca 5: 5 gxfloitation 5, Fshn equpment 5.. Fshng gear There s no specal fshery or fshng equpment for ths prawn, It s caught along wth other prawns and fsh, The man gear used n Bombay s a fxed bag net locally known as 'dol', Setna (949) has gven a farly detaled aocount of the constructon and, operaton of the net. Its length s between 40 and 60 m and vares from plaoo to place along the coast0 The net s fxed aganst the tdal current; at slack water t s hauled and the catch removed, then t m agan set untl the next low or hgh tde, Around Hong Kong traws are used, 5,,2 Fshng boats The Bombay boats are locally fabrcated of teak and are 0 to 5 m n length. They are powered ether by sals or ftted wth nboard marne desel engnes of 5 to 45 hp, Prawn junke are the oraf n use around Hong Kong. 5.2 FahnR areas 5,2. General geographo d.strbu. ton The speces s commercally exploted from wthn 30 km from the coast near Bombay, and to a lessor extent along the Vsakapatnan ooast n Inda, It s also fshed around Hong Kong. 5.2,3 Depth ranges In Bombay the fshng grounds do not exceed 40 m n depth, and near Hong Kong are dstrbuted n shallow waters. 5,3.3 Dates of begnnng, peak and end of season The fshery oommenoem n Bombay n October after the southwest monsoon when only small quanttes aro landed. The maxmum oatchem are reoorded n November and Deoember, The season comes to a 00mo a the onset of' the southwest monsoon rans n June Factors affeotng fshng season In Bombay, several fao'torm suob as the force and duraton of the tdal current, the extent of ranfall over the adjonng land mass, the annual cycle of upwellng of coastal waters and the depth and locaton of fshng grounds, seem to nfluence the success or falure of the fshery (Kunju, 967). 504 Fshng operatons and result Selectvty The gear used n Bombay takes all szegroups. Around Hong Kong the nets used appear to allow small prawns to escape (Cheung, 963), 5,4.3 Catches The annual total average prawn landngs n )laharamhtra, Inda, s 54,662 tons of whch 9.6 percent s accounted fer by 8. Indca (Kunju, 968). 5,5 Fsheres management and regulatons Choung (963) stated that over-fshng of the speces s not a problem n Hong Kong, frstly because the local fshermen do not fsh ntensvely n the nursery grounds, and secondly because the mesh dameter of' the shrmp trawl commonly used s 5 mm whch enables the emaur prawns to escape easly. 5,3 Fshng seasons 5,3. General pattern of fshng season In Bombay the fshery s operatve throughout the year, exceptng the perod from June to September when the prawn moves offshore (see seoton 3.5.). Around Hon Kong the prawn s caught all the year round (Choung, 963). 5,3.2 Duraton of' fshng season See secton 5.3.

17 - 333 FRmS6 S. ndca 6 REFERENCES 6t]. Ahmad, N., Prawn and prawn fshery of East Pakstan, Daoca, East Pakstan Govt. prese, p, Cheung, T.S,, Dstrbuton cf penaed prawns n the waters around Hong Kong. In Inter- 959 natonal Oceanographc Congress, 3 Au,ust - 2 September, Preprnto of abatraots of papers to be presented at afternoon sessons, edted by M. Sears, Washngton, D.C., LUS, pp A key to the dentfcaton of Hong Kong penad prawns, wth comments on 960 ponts of systematc nterest. J.Hongkong Unv,Fsb., (3)6l-9 The natural hstory of the commercal speces of Song Kong Penaodae 963 (Cruetacea, Decapoda), Ann.Ma.nat.Hst,, (3)64O-33 Ral, D,N.F., The Malayan Penaedae (Crustaoea, Decapodo). Part. Introductory 956 notes on the speces of the genera Solenooera, Penseus and naes. Bull.Rafflee Mus,, Observatons on the taxonomy and bology of some Indo-Weet Paofo 962 Penaedae (Crustaoea, Decapoda). Fsb,Publs Colon.Off., 7d-230 Holthus, L.B. and H. Rosa, Jr., 965 value. FAO Fsh.tech,Pap., (52)x2 p. Lst of speces of shrmps and prawns of economc Hubo, I., Studes on the ponaelde of Japan and ts adjacent waters, J,Tokyo Coll.P'sh, (l)l-467 Kunju, W,M., Observatons on the prawn f.sbery of Maharashtra coast. Synp,Ser,mar,bo, 967 Ass.Inda. 2(4) Some. asçeot, of the bology of Solonocora ndca Nataraj, 968 (57)vol.2* FAO Fsh Rep., Lu, J.Y., * Economc shraps and prawns of Northern Chna. Pekng, Marne Bology 955 Insttute, Academy of Scence. (In Chnese) Nataraj, S., On two new speces of ßoeoera (Crustaooa Decapoda Penaedae) wth 945 notes on Solenocera peotnata (Spenoe Bate). J.Asat.Soo,Beng., l9l-8 Satna, S,B., Bombay fshe'nens ngenuty. J. Bombay nat.hst,soo,, 48(3) Wood-Mason, J. and A. Alcook Natural hstory notes from H,M, Indan marne survey 89 steamer INYESTIOkPOR. Ann.Ma7.nat.Hst.,(b) * Not consulted n orgnal