Eight species of spiny lobsters, six shallow water and two deep sea species and two slipper or sand lobsters constitute the lobster fishery of Indi

Radhakrishnan, E V

Vijayakumaran, M

CMFRI Digital Repository

) . ). l . ) . Ills ) )st) LOBSTER CULTURE AND LIVE TRANSPORT M. VIJAYAKUMARANI AND E.V. RADHAKRISHNANl Central Marine Fisheries Research Institute, Cochin 682 014. INTRODUCTION Eight species of spiny lobsters, six shallow water and two deep sea species, and two species of slipper or sand .lobsters constitute the lobster fishery of India. Spiny or rock lobsters have a subcylindrical body with long cylindrical antenna with whip like flagellum. The carapace is covered with numerous spines and tubercles. The slipper or sand lobsters are with a dorsoventrally flattened body and short scalelike antenna without whip like flagellum. RESOURCES Lobster catch in India is around 2000-3000 tonnes per annum and most of it is ex-ported frozen, whole cooked or live. Export of whole lobsters since late 80's and live lobsters since 1993 and the ever increasing demand for Indian lobsters have resulted in their regular and organised exploitation. Maharashtra and Gujarat are the main lobster fishing states followed by Tamil N adu. While lobsters are landed as a by-catch in fish/shrimp trawls in the north-west coast, they are caught by gillnets, traps and occasionally by trawls in the south-east and south-west coasts (Table 1.) Lobsters weighing 200 to 300g are best suited for whole cooked product while those weighing over 300g (greens) and 500g (tiger) are in demand for live lobster export. High demand for live lobsters, which is Rs.600-1500/kg depending on size, has re-cently generated considerable interest in culture/fattening of spiny lobsters. SCOPE FOR CULTUREIFATTENING OF INDIAN SPINY LOBSTERS SEED Seed All commercially important species of shallow water spiny lobsters in India have been bred in captivity, but their whole larval cycle is yet to be completed. Scientists at the Central Marine Fishers Research Institute (CMFRI) were successful in rearing lobster larvae to more than half way stage and efforts are on to complete the larval rearing process. Success has been achieved recently in Japan in completing the life cycle of a few temperate and sub-tropical species of spiny lobsters, but hatchery pro-duced lobster seed is yet a distant dream. Many successful devices have been developed for collection of postlarvae or puerulii, but large scale collection is not possible in India to initiate lobster culture, 'since it Present Address: 1 Madras Research Centre of CMFRl, Chennai - 600 006, 2 Calicut Research Centre ofCMFRl, Calicut - 673 005. 97 will be difficult to collect large numbers from a particular region. Hence, any lobster culture venture in India, at present, has to start with collection of lobster juveniles from nature and growing them to the required size. As there are no size regulation in our country, about a third of our commercial-catch are undersiz€djuveniles. These juveniles can be utilized for lobster culture/fattening. Another stra egy that can b adopted by prospective lobster fanners js fattening of big size lobsters for 2 to 3 months to increase their "grade" in the live export trade. Growth Rate Under sub-optimal rearing conditions, the Indian spiny lobsters, Panulirus homarus and P. polyphagus were grown from puerulii to 80g size in 12-16 months and then to 30g in another 12 months. In the tiger lobster, P. ornatus, 380g size was obtained in 20 months. Fattening of juveniles of lOOg and above to required commercial size is more promising than rearing puerullii to marketable size. The tiger, P. ornatus is the ideal speoies due to its faster growth rate and maximum value:in live axpol't. P. ornatus of 100-150g siz can be grown to 500g in aboll t 8 months in indoor cu1tu~e systems under ideal rearing conditions. Since they attain maturity only a t lal'ger -siz.e (700-800g), ju: euUes of this species are Jnore suited for fannjng to he target size of 5 Og and above. Fattening oflarger size (300-350gto·500; 750-800g to 1{)OOg) can be done in shorter period of 3 to 4 months. The greens P: homarr.u;and P. po~yphagus mature at about 175 t o 200 g and j will be economical 0 I grow them to hia size and sell for whole - cooking purpose. Rerently greens of this size an~ exported live to Hong Kong .. Lobs er farmers of aurashtra in Gujarat (commercial raring of lob-sters i~ prevalent only in S.aurashtra) grow P. polyphagus rom .32-35g size to 100~ .25g in abaut 80 days and sell them f'or whole cooking .. Altemative1y, monosex u1~ ture of greeI)S can be undertaken to gro y them to bigger size~ to prevent loss of energy towards reproduction when males and females are grown together, Growth enhancement by eyestalk ablation Three to seven fold growth enhancement was achieved in four species ofIndian spiny lobsters by bilateral eyestalk ablation (removal of both the.Byes). The tiger has been grown from 100g to 1500 gin 8 months' by this technique. The ethics of enhancing growth by removal ,of ey·es and. the consumer acceptance of eyeless ]obster~ are the poin s to be considered before applying this techniq\l.e. Research is on to find out whether the same result can be achieved by inactivating the eyestalk hormones by laser or other modern techniques, rather than by eyestalk ablation. Factors influencing growth of lobsters Salinity, dissolved oxygen (DO), pH, temperature and nitrogenous metabolic wastes, especially, ammonia, are the major water quality parameters regulating lobster growth. Stocking density, provision of shelter, handling stress and intensity of light also influence growth in captivity. Quality of feed plays a major role in obtaining optimum growth and body colouration (Table 2). 98 )ster niles :m in 'hese ng of ~ade. . arus en to ed in ize is .s the ~t. P. lture r-size ize of :mbe .agus ~and ve to f lob-100-le cul-)SS of spiny been ncing 'e the d out les by astes, )bster flight lining Drastic changes in salinity should be avoided. Moulting and surviva] of lobsters are affected when DO levels fall below 60-70% of saturation level. Hence DO level should be maintained above 4mlll and at still higher concentration when the 'stocking densIty is high. Ammonia :;ncentration in wat r reduces growth rate and it. is important to keep it below 0.1 ppm for optimum growth. Stocking density varies from "UQ .. §,PLtu'J. d(;).pending on thectlnure, ~ystem and s ize oflobsters. It rua be po.':ls ·ble to increase the stocking density in raceway culture with good water turnover. Spiny lobsters hide in crevices in their habitat and appropriate shelters in growout system should be provided. Exce~sive ITifi} 'an~~dling shocld be aVQided . In nature, s pin ' lob.sters feed redominantly n n '. sel ,bJl,rn''U.1l.esl small crAbs; ech' OJ • po1 chaete wor s e . In captivi'J, it prefers mgllW<:§J9 fish . No COln-pOl.Ulded dl" pen t has yet b en developed for spiny lobster and it has Lo be fed on bivalv moHl;lBcs preierahly, F R of 1.79 to 5,2 has been obtained (0 dry matter basi. ) 1'01' mH'mal P. or/wtlts and P. h ma.ru while in ey ,tall abl~i d I bsters. the FCR was around 1. Prospects of comme.rcial l obste-r culture/fattening Culture of spiny lobst 's in dugout pits in intertidal f! r-e.as_D~ iaraUas yielded excellent results. It would be wOI·thwhil to improve this culture scientifically and ex.pl re th poss 'bility of adoption of this meth d in other'ide tical ru'eas There is e f~yt piny lO'bster culture in salt water lagoons and hallow en d sed bays using od, The trays can be attached to fixed stakes in parallel rows . P '~~~~u".i.\os i..oc"'a.uin""til-lolerate wider rpiIgeofsalinity apd can ive in-mudd habitaL aJso, o sibility of rearing this species along with prawns in earthen p:m'lOS with salinity above 20 ppt can be explored. . • 1ihe most promising method of lobster farmi ng/fattening appears to be intensive culture in indoor tanks and fl?w tJ:rough systems. It can be either a semi-closed sys-tem with qiological filters or an open system. In such systems, high density stocking can be made if optimum water quality and feed are maintained. Management of this system is easier. it e selection is very important. for intensjve lobster culture, OJQd uaJi ty seawater should be available and the site should be loffi'ted aWB fr _ . - \ - -illl Y 'f]uctuil,tWns ;:nd industRal and dome~tic sewerage pollution. ninternlpted p wer 'supply and avai1ability 0 • eed in nearby places are other factors to be considsl'ed, t \~ ou d ideal if the site is well connected by road and has an easy access to a ' tJlans por so that-live lobster can be airlifted directly rath~r than sen mg hem. to ancl1leiholding facili!y. ---~-Under optimal enviroinental conditions with good water and feed management, 90% s urvival can be expected, I! 9FGgtus is the ideal species for intensive culture/fattening. A produ~ct.ioll ~f 1 0 ear can be ob ~fned, with l.obsters veigh~g GOQg ~h.from a fatterung UlllLOf - , The sale pnce of 500 g hve P. ornc.tus lS about Rs. 00 per 99 • kg and the total sale price wo'uld be Rs.8,00,000. The operational cost would be around Rs. 5,00,000 per year and the gross profit works out to Rs.3,80,000. The capital in-vestment for construction of a 100 square meter indoor fattening is about Rs.6,00,000. Disease management Lobsters are reasonably sturdy and no serious diseases have been reported in ex-perimental rearing. ¥ou~Death~drome (MDS), leading to death after moulting and failure ofhl;lrdening ; shell are reported, but good water management and feed-ing can control such diseases. However, it is essential to take precautions to prevent enry of p,atlwgens to theJ~ystem through water or throughJ.obster-juveniles. The w~t~ei can be .d· sinfected, if necessary, with chlorine and the juveniles can be quaran-tined and disinfected before they are released to the rearing tanks. Live export of lobsters ~ Live lobster export, started in 1993, touched 24 tonnes in 1994 and is on the upward trend reaching 99 tonnes in 1996. Madras is the main city for live lobster export with a share of more than 90%. Bombay and Thiruvananthapuram are the other cities from where lobsters are exported live. Lobsters are kept alive at the landing centres for two or three days, before they are transported to the city of export. In that place they are again held for two or three days prior to airlifting to foreign destinations. Thus, in a matter of seven days, the lobsters are exposed to netting stress, transport stress (twice - each time keeping them out of water for more than 20 hours) and holding stress (at high density at two places). This may result in mortalities exceeding 10% if proper care is not taken at each step; Since live lobsters cost 3 to 5 times more, mortality in excess of 10% during live transport will make it uneconomical. Proper conditions at holding facilities and efficient means of live packing are necessary to avoid such situations. Holding facilities In door tanks and raeewav§ can be 'used for holding lobsters. Quality sea water is a prerequisite for good holding facility. Closed recirculation system with efficient biological filter can be used to hold 2QtOo.39kIl(m2 for few days. More stocking can be done in raceways and flow through systems. All species of spiny lobsters can be held together and no feeding is required iflobsters are to be held for 2 to 3 dayj3 . Iffeeding is dene, exchange of water is nece:ssaryto remove metabolic wastes. The facility should have uninterrupted power supply and aeration. The DO level should be maintained above 6!lllLL and ammonia level should not be ,snowed to exceed more han O.lppm. Since lobsters are to be kept only for a few days, artificial shelters are not required, but provision of shelters in two or three tiers will increase floor space for the lobsters to rest. Care should be taken to keep the temperature in the holding tanks below ~. 100 ound 3.1 in-',000. n ex-Iting feed-ivent The lran-Nard wih :iti s I are hree ,the ping . two III at nng and is a ient n be held :ling Duld ined !pm. red, ters ~low Since lobsters are brought to the holding facility from different places daily, it is better to quarantine the new arrivals for a day before releasing them to the holding tanks. Only healthy lobsters should be transferred to these tanks . It would be better to have provision, especially at the first holding centre, to hold lobsters which are in advanced moulting stage and those just moulted for two to three weeks . This helps the shell to harden after moulting. Such lobsters have to be fed during fattening. Live transport The metabolism of lobsters is to be reduced to the minimum level, if they are to be kept out of water for longer periods oflive transport. This can be done by reducing the temperature .. The temperature in the live pack should be proportional to the time of exposure and has to be reduced - but not below 4°C depending upon the duration of transport. Cooling down to 13°C is enough iflobsters are to be kept alive for 24 hours . Still lower temperature is required if the transportation period is longer. Before pack-ing, the lobsters may be cooled either gradually to the packing temperature or sud-denly, which might give an anaesthetic effect. Materials for packing Many materials like moist beach sand, sea weeds, bam boo and palmyrah leaf bas-kets, gunny bag materials, hay, saw dust, wood shavings, waste paper, bolting paper, thermocol boxes, polypropylene bottle, polythene bags, frozen sea water and dry ice are used for live transport of lobsters. While any of these materials can be used for internal transport by road or rail, air transport requires strict adherence to lATA live animals transport regulations. The materials for air transport are thermocol boxes, polypropylene bottles with fro-zen sea water, waste paper, gunny or blotting paper, wood shavings/saw dust and adhesive tapes. Dry ice is no longer used for transport of Indian spiny lobsters. The container should be leakproof. The dimension of the thermocol box normally used for air transport is 60x37x23cm and 8.5kg of lobsters can be packed in one box. Gunny piece or blotting paper has to be spread at the bottom and a layer of lobster, with folded abdomen, each covered by paper, has to be kept in a row. A bottle offrozen sea water should be kept at the centre between the lobsters. Depending on the size of the lobster packed, one more layer of lobsters can be kept above this layer with another bottle offrozen water at the centre. Precooled wood shavings or saw dust can be spread at the top, if necessary. The box has to be tightly sealed with adhesive tape and labelled properly before it is booked for air freight. Packing of lobsters can be start@d few hours before booking depending on the quan-tity to be packed. The air traffic regulation might require opening of few boxes at the air port for inspection. The type of packing used for air freight is increasingly being used for internal transport also. The thermocol boxes, which are the most expensive 101 among the packing materials and polypropylene bottles can be used several times for internal transport, reducing the packaging cost. Table 1: Commercially Important Lobsters of India Lobster Species Trade Area of Level of Peak Gears groups 1,1111' Exploitation Exploi season used I tation Shallow water Panulirus Green west & east high December trawl net Spiny lobsters polyphagus* Lobster coasts to February Panulirus Green west & east high December gill net, I homarus* Lobster coasts toMarc~ traps I Panulirus Green south & east Moderate December gill net, versicolor Lobster coasts to February traps Panulirus Tiger south & east liigh December gill net, ornatus Lobster coasts to March traps Panlllirus Red south & east Low December gill net I longpipes Lobster coasts to March traps Panlllims Black south & east Low December gill net, penicillatus Lobster coasts to March traps DeepSea Puerzilus Deep sea west & east rugh December trawl net lobster $ewelli Lobster coasts & to April I Andamans I Linupafus , Deep sea west & east Lvw December trawl net somnioslls Lobster coasts to April IHigh I Sand/Slipper Thenus Sand,slipp west & ,east December trawl net lobster orientalis -er lobster coasts to January Scyllarus Sandlslipp west & east 1.0\1/ December trawl net I sordidlls -er lobster coasts to January *Cultivable Species 102 or Table 2 : Optimum Water Quality Parameters for Lobster Culture Parameter Optimum level Salinity (ppt) Dissolved oxygen (mlll) (higher for intensive culture) Total Ammonium nitrogen (ppm) <0.1 -Temperature °C • 103 

Lobster culture and live transport

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Lobster culture and live transport

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