prospect and status of lobster . coastal aquaculture and mariculture

here we discuss about lobster.Spiny lobster grown in captivity could fetch high price through production of suitable size animals. Live spiny lobsters are sought especially in Japan and Southeast Asian countries. Japanese prefer live lobsters of 200-300 g with deep red external colour. No countries except India could supply as the legal size of most species is above this size. The puerulus after moulting to juvenile takes many months to reach marketable size. Australia, New Zealand, Taiwan and Vietnam harvest puerulii for commercial on growing. Technologies to harvest puerulii have been developed. Unlike the American lobster, Homarus americanus, cannibalism is much less in spiny lobsters and they can be cultured communally. There are currently no land-based lobster grow out facilities in India. Smallscale experimental grow out of lobsters has been attempted with some level of success in various marine culture systems including flow through, semi circulation and full circulation.

lobster harvest
On-growing of puerulii and post-puerulii

Newly settled puerulus is a non-feeding stage and they start feeding after the first moult. A biomass production of 4.7 kg/m2 was attained in P. ornatus juveniles stocked at 43/m2 and fed on natural and artificial feed and estimated that production of 1 kg can be achieved in 18 months. Early studies in Australia (Chittleborough, 1974) reported 2 years for puerulii to reach a marketable size of 60 mm CL at 25° C. P. homarus juveniles was reported to take 12-15 months to reach marketable size of 250 g in laboratory. P. polyphagus puerulii took 2.5 years to reach 200 g. P. ornatus has been grown to 300 g in 10 months in Hawaii. In Taiwan, wild caught animals stocked at 25 g mean weight reached 330 g in 16 months in 200 m2 ponds.

Fattening of low value and undersize lobsters for product enhancement

Ongrowing wild caught seed lobsters are widely practiced in Vietnam, the Philippines and Indonesia. Farming is typically on a subsistence scale (limited by the availability of seed) although the magnitude of production in Vietnam is collectively very large (1000 tonnes annualaly). In Australia and New Zealand, lobster seed cannot be taken for aquaculture except under strict and limited pilot license conditions. However, there is some in sea and on land holding of legal size lobsters for weight gain and/or more favourable (niche) marketing. In India there being no restriction on fishing, large quantities of juveniles and undersize lobsters are caught and marketed. Though there is good potential for fattening to legal size, there is very little attempt. While some entrepreneurs have shown interest, availability of healthy, quality seed is a major constraint. Ongrowing involves holding undersized lobsters, which fetch low price or not accepted legally for export, for short period until they attain legal size These lobsters could be held in tanks, ponds or cages fed with natural or artificial feed. On-growing of los

1. PROSPECT AND STATUS OF LOBSTER FARMING COURSE TITTLE :COASTAL AQUACULTURE AND MARICULTURE COURSE CODE : AQ223 PRESENTED BY DIPU PATHAK REG. NO : 22-F-07

2. INTRODUCTION Lobsters are a low volume, high value resource which support one of the most valuable coastal fisheries in India. Annual landings increased from 350 t in 1965 to 4,100 t in 1985, but has generally declined since then. The current production is around 2,500 t most being exported alive and in whole cooked form to the southeast Asian market. The potential for increasing the yield from the wild is limited, as most of the stocks are fully exploited and near their long term equilibrium yield.

3. Farming spiny lobsters is probably one of the management strategies to be considered to cope with intensifying fishing effort and decreasing lobster stocks. For many years, homarid lobsters alone have been thought to be suitable for aquaculture , as their seeds could be produced in less than 2 weeks when reared at 20° C. On the otherhand , spiny lobster has a complex and prolonged larval phase and earlier attempts to complete their life cycle was unsuccessful .

4. LIFE CYCLE:

5. DISTRIBUTION: Among the nine species of lobsters distributed along the Indian coast, Panulirus polyphagus , P. homarus , P. ornatus and the deep sea lobster, Puerulus sewelli are the most significant commercial species. The mud spiny lobster, P. polyphagus forms a major fishery along the northwest coast comprising Maharashtra and Gujarat coasts. The scalloped spiny lobster P. homarus is mainly distributed along the southwest and southeast coast of India . The ornate spiny lobster, P. ornatus mainly forms a fishery on the southeast coast of India, in the Gulf of Mannar . This is one of the largest of the Panulirus species. Other species which form minor fishery are P. versicolor, P. penicillatus and P. longipes .

6. SEED SUPPLY : Seed in lobster farming refers to the juveniles used for culture. The lobster farming industry requires, large number of juveniles for the culture operations. Lobster farmers have to depend upon naturally available juveniles (500-300 g depending upon the species) which form a substantial portion of the commercial fishery. The seeds thus procured are transported carefully and used for stocking in the grow out system. In Gujarat, exclusive fishing of juveniles of P. polyphagus is carried out in intertidal areas and sold to lobster farmers.

7. COLLECTION AND TRANSPORTATION: Since large quantities of Juveniles to stock a farm may not be available from a single landing centre on a single day, they have to be collected from different centres . To maintain spiny lobsters in healthy condition during onboard transport, the holding tanks should be well aerated. To increase efficiency, a large space of about four times the water volume must be left in container to hold air. Since temperature influences the metabolic activity and rate of oxygen consumption of the animals, high temperature has to be avoided.

8. FLATTENING SUBADULTS : Another attractive proposition is growing larger sizes (300-350g) to the prime size of 400g In a shorter period. Live lobsters of P. ornatus weighing 400g and above are in great demand in the Chinese market and fetch premium price. The fast growing P. ornatus can be grown from 300 to 400g in 2-3 months. So, for fattening, lobsters weighing around 200g will be suitable and this could be achieved in 2-4 months .

9. GROWTH ABBLATION BY EYESTALK ABLATION: Gro wth in tropical lobsters can be accelerated by bilateral eyestalk ablation . Different size groups of P. homarus have been ablated and the ablated animals moulted faster and gained 3-7 times more weight than the control group . The ablated lobster has an average survival rate of 70 %. The practical application of eyestalk ablation in a commercial farm has not been attempted yet and information is Inadequate on the consumer acceptability of ablated lobsters.

10. LOBSTER FARMING IN INTERTTTIDAL PITS: It is a unique system of lobster farming is practised along the northwest cost of India, in Bhavanagar district of Gujarat. Large number of juveniles collected from intertidal areas by a traditional stake net called ' bandhan ' are stocked in ponds excavated in the intertidal area, which are flushed by incoming tidal water twice daily. These ponds or 'pits' are covered by nylon netting to prevent escape of the lobsters. Juveniles weighing 30-50g are grown to 100 125g in 90 days.

11. FARMING SYSTEM : Growing spiny lobsters In growout ponds in India is practised only In Gujarat. Experiments conducted in CMFRl and Tuticorin Fisheries College show that indoor grow out system is most suited for lobster farming. Experimental culture in floating cages has been reported from Tuticorin, but the commercial feasibility of the farming operations Is not available. An indoor growout system consisting of a series of circular or square cement tanks, 9 to 16 square meter area, has several advantages.

12. WATER QUALITY MANAGEMENT : The optimal environmental requirements for lobster farming are :- temperature {26-33‘’C), salinity (25-35 ppt depending upon the species) pH (6.8-8.5) dissolved oxygen (> 3.5 ppm) In recirculation system:- ammonia (< 0.1 ppm) nitrate (< 0.1 ppm)

13. HARVESTING : H arvesting of lobsters from indoor growout system is a matter of draining the water and picking up the commercial size for marketing. In fattening cages and pens, harvesting can be done by lifting the cage or the net in the pens and scooping out the lobsters.

14. MARKETING : The harvested lobsters can be marketed either in whole cooked form or in live condition depending upon the size and species. For whole cooking, live lobsters are dipped in chilled water until they die and then immersed in boiling water containing acetic and citric acid for few minutes. After cooking, the material is again kept in chilled water and then cleaned, packed and blast frozen. For live lobster transport, live lobsters are immobilised in chilled water for few minutes and then packed in thermocol boxes.

15. DISEASE : Poor water quality and hygiene in the rearing system may provide favourable conditions for the growth of epiphytic protozoans, fungi and bacteria. Protozoan infestation can be controlled by treating with 20-30 ppm formalin for one hour. Furazolidone (10 ppm/ hr ) treatment is effective against bacterial infections . Infected lobsters have to be Isolated for treatment.

16. Status of LOBSTER PRODUCTION IN INDIA : In India, though lobsters form only 0.12± 0.06% of total marine landings, they are an important export commodity comprising 1.07±0.44% in quantity and 2.59±1.15% in value. Major share of lobster catch in India is contributed by multiday trawlers (54.3 %) followed by out-board gill nets (26.9 %) and single day trawlers (11.2 %). Among the lobsters, the highly priced spiny lobster forms major portion of fishery (62%) followed by spiny lobster (37%) and deep sea lobster (1%).

17. The fishery improved from 347 t in the year 1965 to 2,991 t in 1975 and attained the maximum landing of 4,083 t in 1985, but has been fluctuating around 2,400 t since then. The major landings come from the northwest, southwest and the southeast coasts. The northwest sector comprising Gujarat and Maharashtra contributed to 69% of total landings during 1996-2000. Statewise , Gujarat contributed 43.7%, Maharashtra 25.4%, Tamil Nadu 14.6% and Kerala 13%.

18. FUTURE PROSPECT : The technology for lobster farming and fattening has already been developed. High demand for lobsters in the international market and the high price , makes lobster farming an attractive industry. But nonavailability of a perfected hatchery technology and limited availability of juveniles and subadults from the wild are the two major constraints facing lobster farming. Small scale farming or fattening can be carried out utilising the undersized lobsters caught along with the commercial size lobsters. Harvesting of juvenile lobsters for farming should be avoided as we have inadequate information on the impact of fishing of juveniles.

19. CONCLUSION : Lobster production in INDIA is very less as compared to other countries like CANADA ,USA,INDONESIA ,AUSTRALIA etc . The annual landing of lobsters in the country is already on the decline . Again, some of the species have already been overexploited in the absence of strict implementation of a legal minimum size and other management measures. Until a hatchery technology is perfected for commercial seed production, conservation measures have to be implemented to ensure sustenance of fishery as well as farming practices.

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