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, 1-1 June 1967 Mexco (Mexque), 1-1 jun 1967 Cudad de Méxco, Méxco, 1-1 juno 1967 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, 1970

2 FAO LIBRARY AN: FAO Ptehsres Synapss No.98 FAm/S98 SÄST - Prawn STNOPSIS OF BIOLOGICAL DATA ON THE PENAHID PRAWN Netapenaeue affne (H. Mme Edwards, 1837) Expos4 synoptque eux la bologe so l4otapenaeue affns (H,!4lne Edwards, 183?) Snopss sobre la bologfa de]. Metapenaeue affns (H. Nuns Edwards, 1837) prepared by N.J. GEORGE Central Marne Fsheres Research Insttuto Mandapan Camp, Inda / Present address: Indan Ocean Bologcal Centre (Natonal Insttute of Oceanography) Pullepady Croes Road, Ernakulam, Coohn-18, Kerala.

3 Fu/s98 M. affne CONTENT&J' Page No, 1 IDENTITY 1:1 1,]. Paxonorqy Defnton 1,1, Descrpton 1, Nomenclature 1,,1 Vald soentfc names 1.. Synonyme 1..3 Standard common names, vernaoular names 1.3 General varablty Subepecf o fragmentaton (raoes, varetes, hybrde) Genetc data (chromosome number, proten specfcty) ' DISTRIBUTION :1.1 Delmtaton of the total area of dstrbuton and ecoloj7cal characterzaton of ths area 1. Dfferental dstrbuton 3,.1 Areas occuped by eggs, larvse and other junor stages annual varatons n these patterns, and seasonal varatons for stages perbs1,ngcver two or more seasons,. Areas ocoaped by adult etag(s:' seabonal and annual varatonz of these.3 Behavourstc and ecologcal deternants of the - eneral lmts of dstrbuton and of the varators of these lmts and of dfferental dstrbuton " 3 BIONOMICS AND LIFE HISTORT 3:1 3.1 Reproducton 1 3,1,1 Sexualty (herme.phrod-tsm, heterosexualty, ntersexualty) 3.1, Maturty (age and sze) 3,1,3 Ìatng (sonogamoas, polygamolle, promscuous) 3.1,4 I"ertlzaton (nternál, exte'nal) 3,1.5 Fecundty 3,1,6 Spawnng Spawnng grounds 3,1,8 Egg: structure, sze, hatchng type, parastes and predators 1 3. Larval hstory 3.,1 Account of embryonc and juvenle lfe (prelarva, larva, pootlarva, juvenle) I Tho nynopss has been preparel accordng to Outlne Verson No, H, Rosa Jr., AO Fn}ì.ynop., () Rev,l, 1965).

4 136 - Plb/598 M. affn 3,3 Adult hstory 3z 33l ,34 3, ,6 Longevty Hardness Compettors Predators Parastes and dseases Greatest uzo 3.4 Nutrton and growth Feedng (tmo9 plao9 nanner season) 34' Food (type, vólume) 3.4,3 Relatve and absolute otk patterns azul ratee Relaton of routh to feedng9 to other aotvttee9 and to envronmental factoro 305 Behavour 3,5,1 ïgraton and local, movements 3.5, Schoolng 3,5,3 Reproductve habta 4 POPULP.TIC (ock) 40. Sex ro JQ 1 AL oopoetou 4.0: s compo-ou 4 Q / Avra 4o o v dec1-.? Changes n des±ty 3 3 4z1 J- 43 and recrutmest 43.1 Naalr 4.3 N' rat&s 4,4 't morbdt e 1o4r,. Rates o mo1y 44 1?aoorQ or oon.qns foctn' moralty 43 Facos or condtons feong morbdty o'o4 Relaos os morbdty o mortalty Ifatss 4,5 Tton C 40 ofjçu b.oroa, rcìuoo EXPLOITATION 5 1 ç_ eup,aenj cc,y nd os Q 5: Fthng gear 1 51 Fnhn boats I

5 Fflm/S98 M, aí'fna '1 5. Fshng areas 51 Paje 5..1 General geographc dstrbuton 5.. Geographcal ranges (lattudes, dstances from coast, otc.)* 5..3 Depth ranges I 5.3 Fshng seasons General pattern of fshng season 5.3. Duraton of fshng season 5.3,3. Dates of begnnng, peak and end of season Varaton n tme or duraton of fshng season * Factors affectng fshng season 5.4 Fshn o eratons and results Effort and ntensty 5.4. Selectvty Catches 5.5 Fsheres management and regulatons 5.6 Fsh farmng, transplantng and other nterventon 6 RRENCES 6 As no nformaton was avalable o the author, these tems have been omtted from the text.

6 M. affnn 1 d 1 IDENTIPY 1.1 Taxonomy 1,1.1 Defnton Phylum Arthropoda Class Cruataosa Subclass Malaoôstraoa Seres Euvalaoostraoa Superorder Eucarda Order Decapoda Suborder Natanta Secton Penaedea Famly Penaedae Subfamly Penaonae Genus Notapenaeua Wood-Mason, 1891 Speces Netapenneus affns (H., Hune Edwards, 1837) 1,1. Desorpton Genus Metapenasus Wood-Mason, n Wood-Maso ant!.!.1000k, 1891, Ann.Mag,nat,Hst., (6)871. Typo speons by orgnal desgnaton, Penaeus azffne H. Mlno 1lwads, 183'f. G ndors masou.- lne, Rostrum dorsally toothed only; carapace wthout sutures; orbtal angle usually sharp; postocular sulcus present; cervcal sulcus well defned; hepatc sulcue not well defned behnd level of hepatc spne, but pronounced n front wth well defned postero-nferor border, usually descendng vertcally from hepatc spne, then turnng towards the pterygostomal angle; antennal and hepato spnes pronounced; pterygostomal angle blunt, Telson wth deep dorsomedan sulcus, wthout fxed subapcal spnes, and wth movable dorsolateral spnes whch may be mcroscopc and very numerous, Frst antennu].ar segment wthout spne on ventral dstomedan border, Antennular flagella usually shorter than carapace. Maxllulary palp wth segments, dstal small, basal wth convex, folaceous projectons on nner and outer edges, and long spne on nner edge, Frst to 3rd pereopods wth basal spnes; 5th peroopod wthout exopod; sohum and merus Often modfed n adult male. Potassa tubular.th thckened medan lobes; lateral lobes thcker than medan, formng dstolateral spoutlke projectons, each wth dorsal lobule produced posterorly nto expanded, plate-lke projecton; medan lobes wth dorsal lobule. produced nto thn reourved plate-lke or hoodlke structure. Appendx masculna wth knoblke dstal pece bearng deep posterodstal de-. presson ora ooulptured n some way,, The1ycr composed of anteror medan plate, posteror lateral plates more or less enclosng posteror end of medan plate; posteror plates often contnuous across sternto, Zygocarìn n sels wth rows of teeth whch go progrorjsvely smaller. Pleurobranche on 3rd o 7 thoraoo somtes, rudmentary a h'obanoh on 1st somte, anteror and posteror ar'ro! on nd to 6th, vestgal anteror and fully developed posterïor arthrobranohs on 7th eoa.í; mastgobranche on let, nd, 4th to 6th sc;.;j, Body usually wth some dorsal eetose depr: areas, remander of body surface varyng fron completely glabrous to covered wth close r-- regular etose depressed areas, (Dall, 1957), Metapenaeus affns (H0 Mme Edwarde,l837) The type specmens of the speces aro n the Pars Museum and were examned there n 1938 by Burkenroad (see Burkenroad, 1963), who found them to be dentcal wth the present speces. Hall (1958) mstakenly took a epecmon of Parapenaaopejs sculptle n the Pare collecton to be the typo of Penaeus effns and concluded that the name affjs could not be used for the present form. Ths queston was put straght by Burkenroad (1963) and the name e!fns can be contnued to be used n the mense t had always been consdered, Type localty. "Côte de Malabar" (=S,w. coast of Indan pennsula, Kerala, Inda), The speces s llustrated n Fg0 l Body tornentose; rostrum more curved, lees uptlted, slghtly larger than that of aoao ceros; not less than 9 dorsal tee pos1ocvcc! crest does not extend to posterov peruj o uac pace; anterolateral angles of caracaco roonded antennal spne strong, produced ac rdge tó small hepatc spne; rdge Jouud!n well marked postantennular groove hoh asetu cervcal groove. Anteror abdomnal terga!- dstnctly carna-ted; 5th abdomnal ooao /3 length of 6th; 6th semte lttle shorter than telson, Telson wthout margnal spnes shorter than endopod of uropod, Eyes very large, slghtly surpassed tennular scale, Upper antennular fnge 11 least 3/4 length of pedunole, 3rd maxllped barely reaches mddle of antennal scalo, clao tylus of male not modfed, Strong spnos present on bases cf all 3 pars of che]jpedc Last par of thoraco legs usually aurpaooog p 01 antennal scale, sometmes by whole lcng,h of daotylus; no lobule on posteror odgo of sohum n male9 notch n the merus bounded by!nteô tooth, edge of morue entre beyond Petasma (Fg, ) symmetrcal, In adult, halves forn compreased tube endng n par of -lpped spouts lke short horns.

7 1365-1* FRn B B M. affn Fg. 1 Fg. Fg. 3 MtaperaouB affns PotaBma. Thelycum, (from Hall, 196).

8 FRm/398 M. affne Thelyoun (Fg. 3) concave, setose. Lateral lobes farly flat, transversely out nto unequal segments, medan plate projects between lobos of sternum between 4th par of legs. Body transluoent groen, uropods tpped wth conspcuous groen. Maxmum length about 180 mm. For artfoal key to the speoms of Metspenaeue seo secton 1.1, of the synopss on Metaponaouo monooeros by George (1970), or Racok and Dall (1965). 1. Nomenclature 1..1 Vald soontflo nanes Metapanaeuo affns (H. Mme Edwards, 1837). 1.. Synonyms Objeotve aysonymy Penaeus affns H. Mmo Edwards, 1837, Hst,nat.Cruet., m 416. (orgnal combnaton). Parapenaeus affns (H. Mme Edwards) Rathbun, 190, Proc.TJ.S.Nat.Mus., 6: Mets onaeus affns (u. Mmo Edwards) Nobl 1903, Boll.Mus.Zool.Anat.00mp,Torno, 18(4473. Penaeopam affns (H. Huno Edwardô) Man, 1911, Sboga Exped., 39as57, Subjectve synonymny 1:3 Penaeus mutatus Lancheater, 1901, Proc. zool,soc. London, l90l57. Metapenaoum neoopnans Hall, 1956, Bull. Raffles Mus., 7:. Motaponeua mutatue (Lanohester) Hall, 196, Fsh.Publ,, London, 17:76, 1..3 Standard common nanes, vernacular nanes In Kerala, on the southwest coast of Inda, the speces s locally known as "Kazhanthan ohemeon", In Bombay, on the northwest coast, t s locally oalled "Jnga", and n Bengal, on the bast coast, the name "Chngr" s appled to ths and related speces. 1,3 General varablt Subepecfo fragmentaton (races, varetes, hybrds) No subspeces or varetes are known for the speces,

9 FRnt/898 L affne,1 DISTRIBUTION.1 Delmtaton of the total area ot dstrbuton and ecologcal characterzaton of ths area General dstrbuton of the speces s Indan seas through Malaysa and part of Indo.- nesa to Hong Kong and Japan. Under the FAO dstrbuton code (see Holthu and Rosa, 1965) t occurs n land areas 41, 43, 433, 434 and 437, and water areas 15W and ISEW, n marn. and bracksh waters. In Indan waters, the juvenles of the speces are found n very small numbers n the backwaters and estuares, and adults 000ur n the nshore waters to a depth of about 5 foe (45 n). In Ceylon, t s found on mud banks n the sea t a depth of 8 to 1 foe (14 to m)(de Drum, 1965), In Malaysan waters the juvenles are found n the Sngapore pond fshery n small numbers and the adults n larger numbers n the seam around Malaysa, (Hall, 196),. Ifferental dstrbuton,,1 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 There does not seem to be such lar-soa10 mgraton of the postlarval stages nto nearby estuares os n M. dobson, (Nere) end the apeoes never accounts for moro than 0 percent of the catch n the fshery or juvenle prawns La the backwaters of Coohn, In the Sngapore pond fshery, a000rdng to 1l (196), juvenles of!. off ma occur sporadcally from Pebruary to September but never exceed 6,5 peroent of the prawn populaton. The speces o present n small numbers n estuares 1moot throughout the year and most common from January to June, In the Chlka Lake, on the east coast of Inda, Kemp (1915) recorded the speces n February and Maroh and concluded that t may be present there at all seasons,,. Areas ocoupod by adult stages: seasonal and annual varatons of these On the mshox'a fshery grounds of the west ooast of Inda, adults of the speces are most common n November and December (George, 1961), and on the offshore grounds they are most abundant from November to January (George, Raman and Nor, 1968e.). In Penang, a000rdng to :l1 (196), there s some ndoaton that the adulte are most abundant n August-September. So far ho work has been reported on the eggs and larvae of the speces. Accordng to Subrahmanyam (1967) the speces may breed n nshore waters of the southwest coast of Inda,

10 FRmLS98 M. offms *1 3 BIONOMICS AND LIF'H HISTORY 3.1 Reproduoton Sexualty (hermaphrodtsm, heterosexualty, nter-. sexualty) M. affne s heterosexual, as are all ponaed prawns. HaIl (196) recorded one hermaphrodte n o total of 77 spoomens, from a Sngapore prawn pond Maturty (age and sze) Menon (1957) and Subrabsanyam (1967) mentoned that sexual maturty s reaohed at a length of about 10 mm. Rao (1968) recorded the mnmum length at maturty as 88,6 mm, correspondng to the late 0 year class. By ova dameter and other studes he classfed the dfferent maturty ste of the female as 'mmature', 'early maturng, 'late rnaturng, 'mature' and 'spent-recoverng'. Shakhmahmud and Tembe (1960) classfed specmens from Bombay waters nto only 3 stages, namely, mmature maturng and mature Fertlzaton (nternal, external) As n other penaed prawns, fertlzaton o external, takng place at the tme of spawnng. Hudnaga (1941) made some observatons on the fertlzaton, the number of entrance cones, etc, Fecundty Fecundty of the speces, as estmated by Rao (1968), ranges between 88,000 to 363,000 eggs. Aocorth.ng to hm there s a lnear logarthmc relatonshp between the number of eggs produced and the sze of the prawn, The formula s Log F -0,4306+,7179 Log L where F s the number of mature eggs and L s the total length n mm Spawnng From a study of the nshore fshery of the southwest coast of Inda, George (1961) reported the breedng tme of the speces to be from October to December. Later, from the study of the trawl catches of the speces off Cochn, George et al.(1968a) concluded that the actve breedng season of the speces s from Nov-ember to February, Rae (1968), usng the maturty condtons of the catches off Cochn, also arrved at a smlar concluson, the breedng season beng Ootober to March wth peak n November to December. January to March s the spawnng perod n Calcut waters accordng to Subrahmaryam (1967). In Bombay waters, Shakbmakmud and Tombe (1960) found most mature and maturng females n October and Aprl to June. Smlarly, Hall (196) reported peak breedng seasons for the speces n Malaysan waters, namely, May to June and October to December. Hudnaga (194) has found that the speces spawns whle swmmng about or vgorously movng the pleopods when spawnng at the bottom. Under other condtons, eggs faled to hatch. Utlzng the data on the monthly dstrbuton of late maturng and mature females n 10 mm length groups n the catches off Coohn, Rao (1968) concluded that the epeces spawns more than once durng ts growth from 91-lOO mm to mm Spawnng grounds Subrahmanyam (1967) studyng the breedng of the speces n Calout, and on the southwest coast of Inca, observed that the speces moves to offshore areas for spawnng, Studes at Cochn, on the mane coast, ndcated that the speces may be breedng n the 15 to 5 fa (7 to 45 m) areas, In Malaysan waters Hall (196) observed the speces breedng very close nshore, In Bombay waters, Shakhmahmud and Tombe (1960) observed that there are ndcatons that the speces prefers areas of soft mud, rch plankton and shallow coastal waters for matng and spawnng. 3,1,8 Egg: structure, sze, hatchng type, parastes and predators The most hghly developed ovaran eggs measure 0.35 mm accordng to Rao (1968). He has gven measurements of varous stages of maturng eggs. No nformaton s avalable on the spawned eggs, hatchng, etc, 3, Larval hstory 3..1 Account of embryono and juvenle lfe (prelarva, poatlarva, juvenle) In the embryonc development of the speoes, Hudnaga (194) observed the secnentaton to be qute smlar to that of Penaeus japonous, whch he descrbed n consderable detal, The larval development of the speces s descrbed by Hudnaga (1941), There are 6 requtngs n the nauplus stage, 3 n the protozoea, and 3 n the myss stage, after whch the larva passes nto the postlarva The nauplus stages do not feed,

11 FRm/S98 M. affns 3 Hudnaga (1941) obtaned good results by rearng the zoea of the speces on Skeletonema ooutatum n the laborator. Mohamed, Rae and George (1968) descrbed the frst postlarva. 3.3 Adult hstory 3.3,1 Longevty Subrahmanyam (1967) r000rded that the speces may lve for 3 years or slghtly more. Accordng to George etal.(l968a) from a study of the trawl catches off Cochn only year classes of the speces oontrbute to the fshery. 3,3. Hardness Lke most other ponaeds, the speces can wthstand only a mnmum of handlng. 3,3.3 Compettors The spooes occurs on the fshng grounds off the coasts of Inda along wth other speces, and undoubtedly there wll be compettors wth them for food, 3,3,4 Predators Penaeds n general are preyed upon by the domersal fshes of the area where they exst. There aro records of 'penaeds' 'prawns', eto., as formng major porton of food of several speces of demersal fshes. 3,3.5 Parastes and dseases There are no reports of parastes or dseases of M. affns. 3,3.6 Greatest sze The maxmum sze of the speces accordng to Aloock (1906) and Menen (1957) s 6Y n, (165 mm). George etal.(1968a) report a maxmum sze of 170 nun. 3.4 Nutrton and growth 3,4,1 Feedn (tme, plaoe, manner, season) By analyss of the etomaoh contents of 30 specmens caught durng daylght from the Strats of Malacca, Hall (196) classfed the epeces n a group feedng manly on vegetable matter, No nformaton s avalable on feedng tme, season, etc Food (type, volume) The tems of food, n ther order of abundanoe n the stomachs of the 30 specmens, are vegetable matter (manly angosperm tssue), small oruetaooans (opepods and ostraoods), Polychaota, echn-d setae, molluecan shell peces and fsh remans, Except for 1 empty stomach, sand grans were lwaye present, some of the grans beng large, but the quantty was not great (H 11, 196). Accordng to Subrah manyam (l967 the speces s an omnvorous feed.. er and larger prawns show a preference to a mollusoan det Relatvo and absolute growth patterns and rates George et al, (l968a) studyng the f jabery of the spoc.'. n Cochn trawl catches, recorded a growth of specmens n the st year of 0 mm among males and 5 mm among females n about 6 mo, Dfferental rates of growth n the sexes, females showng a faster growth rate, has been recorded by George (1961), Subrahmanyam (1967) and George et al. (].968a). In the Seto Inland Sea of' Japan, Yasuda (1956) olasfed ths speces n a group n whch the young shrmps do not grow for a lmted perod and thereafter grow very rapdly before the spawnng season. Hall (196) related weght and carapace length by the formula 770 W 0,7079C based on 183 observatons, The formula accordng to Subrahnanyam (1967) s W L.7867, where L refers to total length, 3,5 Behavour Mgraton and local movements Juvenles mgrate from the sea to backwaters and estuares, but not to the same extent as some other speces lke M. dobson and Penaeus ndcus. In the Cochn backwaters, juvenles of ths speces are present n very small numbers n most months, but t s probable that most of the postlarvae do not leave the sea, In the offshore shrmpng grounds off Cochn, George, Banerj and Mohamed (1968) recorded some movements. Accordng to them ths speces and others move to deeper waters durng the monsoon perod and return azfter the monsoon, Subramanyas (1965) studyng the mgraton of the speoes n the Godavar emtuarne system on the east coast of Inda, found more emgraton of the speces durng the nght. Acoordng to hm, ntense emgraton was n Aprl, May and early Juno, Immgraton sas notced to be most marked at dawn.

12 FErn S98 M. a!fns 3, Schoolng Large concentratone of the speoem are known to occur n shoals, along wth other. speces, n the mud bank areas off the southwest coast of Inda and almo n the shrmpng grounds of the coast, 3.5,3 Reproductve habts Observatons have been made by Hudnaa (194) on spawnng behavour n captvty (see secton 3.1.6) but there are no other aocount of reproductve habts.

13 - 137]. - FRmJS98 M. affne 4 POPULATION (STOCK) 4.1 Structure 4,1.1 Sex rato Menon (1957) has desorbed. n detal the sex rato of the speces from the nshore catchen of the southwest ooast of Inda. The sex ratos accordng to hm are shown n Table I. Year TABLE I Percentage of malos n total catch and the sane for speomens of over 10 mn Total catoh ,0 44. Over 10 mm 47, , Accordng to hm, the populaton of mmature prawns (up to 10 mm)contans smlar numbers of each sex. Among older prawns (above 10 mm), however, there s consderable dsparty, females outnumberng males by 11.6 percent. Subrahmanyam (1967) found f ema1e domnatng n the catches from Calcut waters, George and Rao (1967) statstcally analyzed the data on sex ratos of the speoee n the offshore' trawl fshery off Coohn, and found that, unlke 3 other co-exstng speoes, the two sexes were present n smlar numbèra throughout the year, Any mgraton from these grounds muet therefore nvolve smlar nuners of eaoh sex. In Bombay waters, Shakhmahmud and Tombe (1960) recorded more females throughout the year, especally durng the months of October, November and December. 4zl classea make ther appearance n the latter half. The lato 0 year class s also raprenented n the nshore fshery n sorno months, In the backwater fshery only the 0 year class o represented. 3 year classes are represented n the coastal waters of Calout (Subrahsan-tm 1967). Malee and females grow up to 105 mm, 135 mm, 155 mm and 115, 155 mm, 175 mm durng the 3 years respectvely, 4.1,3 Sze composton In the nshore fshery of the soutbwet coast of Inda (George, 1961), the promnent length groupa aro 71 to 75 mm and 81 to 85 mn n February to Aprl. In November and. December the promnent groups are 11 to 15 mm and 16 to 130 sm, In some years the mode reaches 136 to 140 mm n January or February. In the trawl fshery (George et al,, l96a) from October to January larger sze6, wth lengths between 11 and 140 mm,are represented n larger numbers than n the nshore fshery. Towards the mddle of the season,.e. after February, sm11er szes between 1].]. and 115 mm come nto the fshery. In the Bombay fshery (Shakhnahmud and Tombe, 1960) the speces ranges n sze from 45 to 156 mm n length. 4.3 Natalty and recrutment In the nshore fshery (George, 1961), recrutment of bgger specmens nto the fshery commences n October. After December o January the smaller specmens get recruted nto the fshery, In the offshore trawl fshery off Coohn also moro or lesa the same pattern observed (Geor et al., 1968g). Recrut-. mont of postla,rvae nto the backwaters s on a small scale compared to other speces. 4,1, Age composton George (1961) and George et al.(].965a) have mentoned the age composton o &,he spe ces n catohea of both the nshore and off... shore fsheres off Cochn. In both cases the fshery s sustaned by the let and nd year classes. In the trawl fshery, the nd year classes generally enter the fshery n the earler half' of the season and the let year

14 FRm/398 T'I. rlffns 51 5 EXPLOITATION 5.1 Fshng equpment 5,1,1 Fshng gear In the Bombay area, the 'dol' net or bag net s the gear used for oatohng prawns. The detals of the 'dol' nets and ta operaton have been descrbed by Setna (1949). On the north Kanara coast, the prawns are oaught by ahora senes yend bale'), the detals of whch are gven by Pradhan (1956), On the southwest coast of Inda, varous types of boat senes (locally oalled, 'thangu vala', vatta valar, 'koru valar), shore eeneø ('kamba valar, 'nona vala'), drag nets ('vad vala') nd cast flete are employed, Powered boats use shrmp trawla of varous szes Fshng boats The nshore fsheres are manly operated from dugout canoes and plankbult boats wth outrgger. Powered fshng vessels are generally medum szed 7 to 11 s pablo boats, havng 10 to 30 bhp engnes. 5. Fshng areas 5,.1 General geographo dstrbut on The speces s fshed n Indan waters, partoularly on the west coast, and round the coaotn of Ceylon and Malaysa Depth rangos Juvenles are fshed n small numbers n the baokwaters and estuares, ncludng paddy felds, of the west coast of Inda n shallow waters rangng from 1 to 5 m, Young adults and, adults are oaught from depths up to about 30 1m (54 s) from Che zou, In the trawl fshery off Cochn, Goor el al, (1968 a) reported a concentraton of Lbs ces n the 10 to l fm (18 to 0 s) depth regon, In Bombay (Shakhmahmuc and Pembe 1960), the depth from whch these prawns are caught ranges from 4 to 7 fm (7 to 13 s). The Sngapore pond, from whch Ball (196) recorded ths speces,had an average depth of 4 ft (1, m) at hgh tde, In Ceylon, M, affn,s te found n 8 to 1 1m (14 to ) (De Brun, 1965), 5,3 Fshng seasons General pattern of season The fshery for M. affn Leude to be seasonal n all areas where IL occurs, but the perods of peak abundance vary between the dfferent fsheres Duraton of fshng season See secton ,3.3 Dates of begnnng, peak and. end of season In the Sngapore pond fohorì Lh! ooco±oo s represented sporadcally by uû.lkjz Aprl, May and June (Hall, l96) In the backwater fshery of Ooctl Lbs opeoes s most abundant from Jrnuer Lo 'u'c, The percentage contrbuton of the specez, gven by Menon and Rasan (1961)0 lo ohou In Table II, George (1961) gave the percentage oontrbutton of the speoes to the nshore ftehsry of the southwest ooast of Inda for 1956 TABLE II Showng percentage values (numercal and weght) of M, n the monthly oatohea n the stake net oatohes at Coohr from February 1957 to January 1958 Months Feb. Mar, Apr, May June July Aug. Sept, Oot, Nov, Deo, Jan0 By weght 9,5 10,3 9,9 5,9 1,7 By number ,3 l5.3 11,4 16, ,1,

15 t through Its hghest percentage s reached n the poet-monsoon months, November and December, and t s fshed from October to May. The peak season for the speces n the trawl fshery off Coohn (George et al., 1968a) s from Deoember to February. Detaled dstrbuton of the speoes from 1958 through 1963 s gven by thorn. In Bombay waters (Shakhmahrnud and Tombe, 1960), although the speces s avalable throughout the year t s moro plentful from January to March, In 195 to 1954 the speces formed 1.3 percent of the Bombay prawn ostoh. In Calcut nshore waters the fshng season s January to August (Subrahmanyan, 1967) Factors affectng fshng season The nshore fshery on the Malabar coast ntensfes after the annual formaton of mud banks, on whch the prawns concentrate. The fshery n the backwaters of Kerala s probably nfluenced by ranfall and lunar perodcty (Menon and Raxnan, 1961). Subrahmanyan (1967) found a postve relatonshp between bottom salnty and abundance of the speces, 5.4 Fshng operatons and results Effort and ntensty George (1961), studyng the prawn fshery of three centres of the Kerala coast for the years 1956 through 1960, used the total effort and ntensty of fshng and establshed a relatonshp between catch-per-man-hour and recrut szes. M. af fns, however, makes only a mnor contrbuton to ths fshery. In the trawl catches of Cochn, George et al. (].968a) studed the effort and ntensty of fshng through the years 1958 to 1963 and concluded that there s no overfshng n the area. In Table III the catch and effort for one season s shown. 5.4, Selectvty FRrn/S98 M. affna Nono of the fshery as t exsts at present s very selectve as regards sze ospøoes. 5,4.3 Catches Tharn Al Kow (1954) gave the total prawn catch (ncludng ths speces) from a 0 aore prawn pond n Sngapore, and Hall (196) gave the weght of prawns (agan ncludng M. affne) passng through Sngapore markets n 195 to George (1961) and George et al. (1968a) gave the total catches of prawns, ncludng ths speces, for certan Indan areas. Menen and Raman (1961) gave total catches of prawns at two centres In the backwaters of Coohn. Subrarnanyam (1965) gave the total catches of ths and other speces for the new moon and full moon perods n the Godavar estuarne system, on the east coast of Inda. He also gave hgh tde and low tde catches of the prawns, 5.5 Fsheres management and regulatons In southwest Inda, the paddy feld fshery s legally restrcted to the perod from the mddle of November to the mddle of Aprl. Ths regulaton s mposed n the nterests of rce cultvaton, and not to protect the prawn stocks. 5.6 Fsh farmng1 transplantng and other nterventon In the paddy feldsof Kerala, prawns may be hold n the felds for a few days before trappng, but ths s manly to wat for a convenent tde. A few decades ago, young prawns were allowed to grow n the paddy felds for or 3 mo before trappng, but ths practce e no 1oner followed. TALH III Total catch and catch per hour of Metapeneus affna n the trawl catobes for the season Year Month Percentage Total Total Catch of Catch per Catch per by weght catch of effort M.affns hour for hour for prawns n bra all prawns M.affns (kg) (kg) (kg) 1959 November 0, ,o 1.6 December 8, , January 49, ,0.9 February 8, ,0 0.5 March 55, Aprl ,0 May 9,

16 FRmJ98 L affrs 6:1 6 REFERENCES Aloock, A., The prawns of the Peneus group. In Catalogue of the Indan decapod Crust-' 1906 acea n the collecton of the Indan Museum. Calcutta, Part 3, Macrura, Fase, 1, 55 p. Burkenroad, M.D., Comments on the petton concernng penaed nanes (Crustaoea, Decapada) 1963 (,N(S.)96), Bull.zool.Nomoncl., 0(3): Dall, W., A revson of the Australan speces of Penaenae (Crustaosa, Decapodax 1957 Penaodao). Aust.J,mar.freshwat,Res., 8()z De Drum, G.H.P., Ponaed prawns of Ceylon (Crustacea, Decapoda, Penaedae). Zo81, 1965 Meded.,Leden, 41(4): de Man, J.G,, The Decapoda of the Sboga expedton. Part 1. Famly Penaedae Sboga Exped., 39al3l p. George, M.J., Studos on the prawn fshery of Cochn and Alleppey coast. Indan J, 1961 Fsh,, 8(l):75-95 Synopss of bologca) data on Metapenaeus monoceros (Fabrous). FAO 1970 Fsh.Rep., (57)Vol.4:l539'57 George, M.J. and P.V. Bao, Dstrbuton of sex ratos of penaed prawns n the trawl 1967 fshery of Coohn. Synp.Ser.mar.bol.Ass.Inda, (): ueorge, M.J,, S. K. Banerj and K. H. Mohamed, Sze dstrbuton and. movement of the 1968 oouuneroal prawns of the southwest coast of Inda. FAO Fsh.Rep., (57) 3'o1.* George, M.J., IC, Raman and P.K. Nar, Observatons on the offshore prawn fshery of l96&a Obohr, Indan J.Flsh., (l963),1oa(): Hall, D.N.F, Th Malayan Perìaedae (Crustacea, Decapoda). Part 1. Introductory notes 1956 on the s»eces of the genera Solenocera, Penaeus and Metapenaeus. Bull. af'ee Mue,, 7:68-90 tnctons between Metapenaeus monoceros (Fabr.) and Metapenaeus enss 195g (tve an) (Crustacea, Decapoda). Arrn.Mag.nat.Hst., 1(8)s537-44,, Dbservatons on the taxonomy and bology of some Indo-West Pacfc 196 Penaedae (Crustaoea, Decapoda). Fsh.Publs colon.off., 17:9 p. Holtbus, L.B. and H. Rosa, Jr., Lst of speces of shrmps and prawns of economa 1965 value, FAO Fsh.tech,Pap.,(5):1 p. Hudzga M., On the nauplus stages of Penaeopss monoceros and Penaeopss affda. p.941 Prcc.scent.Fshery Ass.,Tokyo, 8(3-4) Reproducton, development and rearng of Penaeus japoncua Bate. Jap.J, 194 Zool., 10(): Kemp, S., Fauna of the Chlka Lake. Crustaosa Decapoda. Mem.Indan Mus., 5(3):0l Lancheater, W.F., On the Crustacea collected durng the Skeat Expedton to the Malay 1901 Pennsula, together wth a note on the genus Actaeopas. Part 1. Brachyura, Stomatopoda, and Macrura, Proc,zool.Soc London, 19O Menon, M.K., Contrbutons to the bology of penaed prawns of the southwest coast of 1957 Inda. 1, Sex rato and movements. Indan J,Fsh,, 4(1)6-74

17 FBm S 8 M. affna Monon, M.K. and K. Raman, Observatons on the prawn fshery of the Cochn backwaters 1961 wth specal reference to the stake net catches. Indan J.Fsh., 8(l)1-3 Mme Edwards, H., Hstore naturelle des crustacée, comprenant l'anatome, le phyao loge et le classfcaton de ces anmaux. Pare, Vol., 53 p. Mohamed, K.H., P. V. Rao and. M. J. George, Postlarvao of penaed prawno of mouthvest 1968 ooast of Inda wth a key to ther dentfcaton, FAO Fsh.Rep., (57) Vol.* Pradhan, L.B., Mackerel fshery of Karwar. Indan J.Fsh., 3(1), Raook, A.A. and W. Dall, Lttoral Penaenae (Crustacea Deoapoda) from northern Australa, 1965 New Gunea and adjacent waters. Vorh.K,ned.Akad.Wet., 56(3)l1l9 Rao, P,V., Maturaton and spawnng of the penaed prawns of the southwest coast of Inda FAO Fsh.Rop., (57)Vol.,85-30 Setna, S.B., Bombay fshermen's ngenuty. J.Bombay nat.hst.soo., 36,887-97, 40(3)t Shakhmahmud, P.S. and V.B. Tombe, Study of Bombay prawns: the seasonal fluctuaton 1960 and varaton n abundance of the Commercally mportant speces of Bombay prawns wth a brìef note on ther sze, state of maturty and mex rato. Indan J.Fsh., 7(1),69-81 Subrahmanyaxn, C.B., Notes on the bonomcs of the penaed prawn Metaponaeus affns 1967 (Nlno Edwards) of the Malabar coast. Indan J.Fsh., (1963), 1OAT1)sl1- Subramanyam, M., Lunar, durnal and tdal perodcty n relaton to the prawn abundance 1965 and mgraton n the Godavar estuarno systems. Fshery Technol., Ernakulam, (1)6-33 Tham Ah Kow, The shrmp ndustry of Sngapore. Proc.Indo-Paof,Feh.Coun., 5(-.3)tl Wood-Mason, J, and A. Alcook, Natural hstory notes from H.M. Indan martne survey 1891 steamer IN'VESTIGAPOR. Ann.Mag.nat.Hst., 8(6):68-86 Yasuda, J., Shrmps of the Soto Inland Sea of Japan, Proc.Indo-Paof.Fmh.Coun,, 6(3) * e * s e e e e *