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  1. Mud crab culture
  2. Introduction: • Among the marine edible crustaceans, crabs occupy third position by virtue of its delicacy, demand and price. • Genetic studies shows that there are four Scylla species distributed from red sea to Indo-Pacific region. • Scylla serrata, S. olivacea, S. tranquebarica, S. paramamosain.
  3. Global distribution • S. serrata : South Africa, French Polynesia, Japan, and Australia. • S. tranquebarica and S. olivacea is limited to the South China Sea, extending into both the Indian Ocean and western Pacific. • S. paramamosain is the most restricted species found only in the Java and South China Seas.
  4. • The species of the genus Scylla, are widely used for aquaculture purpose in the Indo- West Pacific region. • Thailand, Malaysia, Indonesia, Philippines, Singapore and Taiwan, mud crab farming is practiced on commercial scale
  5. • There are only two species of mud crabs occurring in most of the Indian brackish water areas and inshore seas. • Scylla tranquebarica: maximum size of 2.3 kg. • Scylla serrata: maximum size of 0.7 kg.
  6. Scylla serrata Scylla tranquebarica
  7. Biology: • The males growing to larger sizes than females. • omnivorous and they feed on shrimps, crabs, bivalve molluscs and fish. • The females S. tranquebarica reach sexual maturity at a size of about 12 cm (CW) and • In S. serrata 8.5 cm in the brackish water or sea.
  8. Mating: Male cradling female Scylla serrata Mating of Scylla serrata with male uppermost and female turned upside down
  9. 12-day-old eggs (≈ 330 μm diameter) attached to setae, showing pigmentation of eyes and body
  10. Newly hatched first zoeal stage (Z1) of S. serrata next to unhatched egg. The fifth zoeal stage (Z5) of S. serrata.
  11. Megalopae metamorphose from the Z5 stage, developing large claws. The first crab stage (C1) of S. serrata, after metamorphosis from the megalopal stage
  12. Farming of Mud Crabs: • Desirable water quality parameters:  Salinity 10-34 ppt.,  Temperature 23-30°C, Dissolved oxygen above 3 ppm and pH 8.0-8.5. • Commercial mud crab farming is done by two methods.
  13. Grow-out method: • Juvenile crabs are grown to marketable size in earthen ponds for a period of 3-6 months. • In India, crabs formed secondary crop along with shrimp in pokkali fields of Kerala, bheries of west Bengal, and Khazan lands of Karnataka. • Crab farming in earthen ponds is done either in monoculture or in polyculture with other organisms. (milkfish, penaeid prawns and seaweeds).
  14. • small ponds (0.3 to 0.5 ha) with sandy or sand-covered muddy bottom and a water depth of 1.5 m are ideal for crab farming. • Crabs are capable of climbing over the bunds, which is prevented by fixing overhanging fences on dykes. • The height of the fencing ranges 0.5-1.0 m above the dykes.
  15. • The seed crabs collected from the wild are stocked in the ponds after acclimatization. • Stocking density @2 to 5/m2 for monoculture. • Feeding with bivalve meat or trash fish @ 5 to 10 % of body weight. • The juvenile crabs attain marketable size of 200-300 g in a period of 5-6 months
  16. Fattening: • The medium sized or large sized crabs, preferably post-moult crabs, are reared in cages, pens or ponds for about 20 to 30 days till the shells are hardened with additional gain in weight. • Immature female crabs are hold until their gonads develop and fill the mantle cavity. • In countries like India, newly moulted crabs of sizes above 550 g and about 15 cm CW are obtained alive from commercial catches and subjected to fattening in ponds, cages or pens.
  17. • The stocking density is normally 1 crab/ 1 to 3 m2. • In addition to fattening in ponds, cages made of areca nut palm are also used increasingly in the open backwaters in States like Kerala. • The crabs are harvested after the shell becomes sufficiently hard and before next moulting takes place. • Crab fattening/hardening is done profitably by repeated stocking and harvesting.
  18. • Taiwan: small ponds (50-600 m2 ).  Female crabs measuring 8-12 cm CW are stocked @ 2- 4/m2 or 1/m2 during summer. • Thailand : ponds and pens. (Surat Thani ) stocking size of about 415 g, for a month six crops are taken a year. • Malaysia: Floating cages.  Crabs are stocked at 10/m2 The market size is 300-500 g, although they may reach 1 kg. • Fattening of crab is profitable, Because of low operating cost, high survival rate due to control of cannibalism and short rearing period and good market demand for finish product.
  19. Crab fattening pen in a crab-growing pond at Bone, South Sulawesi, Indonesia
  20. Individual crab fattening in a basket in the Mekong Delta, Vietnam. Trash fish is added for crab feed.
  21. Crab fattening cages in a tambak (brackish-water pond) at Timbulsloko, near Semarang, Central Java, Indonesia
  22. Constraints: • Crab farming will remain small-scale until hatchery techniques are developed and improved. • Low survival and heavy cannibalism are the problems in larvae-culture. • The inadequate supply of seed at desired time has been considered as limiting "factor in crab farming. • Destruction of nursery grounds and increased fishing activity may damage the resource potentials.
  23. References: • Suseelan, C., (1996). Crab Culture and Crab Fattening, In: Bull. Cent. Mar. Fish. Res. Inst., 1996, 48: 99-102. • Marichamy, R., (1996). Crab Farming Potential India. Proceedings of the Seminar on Fisheries – A Multibillion Dollar Industry, Madras, Aug 17-19, 1995. pp. 115-122. • S. Kulasekara pandian et al., (2009). Training manual on Mud Crab Breeding and Culture. CIBA
  24. Culture of Lobster:
  25. Culture Of Lobster: • A highly priced seafood delicacy. • Demand for both live and whole-cooked lobster in the South East Asian countries. • The potential for increasing the yield from the wild fisheries is limited, as the stock is subjected to extreme fishing pressure. • Hence, the best management strategy is increasing the production through population enhancement and aquaculture.
  26. Commercially important species of spiny lobster • Panulirus polyphagus (mud spiny lobster): - Maharashtra and Gujarat coasts • P. homarus (scalloped spiny lobster): –Along Kerala and Tamilnadu coasts. • P. ornatus (Ornate spiny lobster): - The southeast coast of India.
  27. Panulirus polyphagus P. homarus P. ornatus
  28. Biology: • In tropical waters spiny lobsters do not have a particular breeding season. • Fecundity varies from 1 to 15 lakhs. • Nocturnal feeders, with specific predatory feeding habit. • The eggs hatched out as phyllosoma larvae.
  29. Life cycle:
  30. Lobster farming: • Farming can be done by two methods i.e. Farming and fattening. • In India, lobster culture has become popular in Bhavnagar, Gujarat. • Juvenile lobsters are caught using stake net from shallow coastal waters they are grown in small ponds covered with nylon nets in the intertidal region of the beach. • Lobsters of over 500 gm are exported live to the Southeast Asian countries. • The smaller lobsters are either frozen or whole-cooked for export.
  31. Optimum water parameters: • Temperature : 26-33ᴼC, • Salinity: 25-35 ppt • pH: 6.8-8.5 • dissolved oxygen: > 3.5 ppm. • Ammonia < 0.1 ppm and • Nitrate < 0.1 ppm
  32. • Stocking density: for farming in indoor grow out system would be 10-15 lobsters/m2 and for fattening: 5 numbers/m2. • Feeding with molluscan meat, trash fish, compounded feed, etc. • Experimental studies show that growth is enhanced by eyestalk ablation and mono-sex culture. • Disease is generally not a serious problem in lobster farming, but sudden fluctuation in environmental conditions causes Moult Death Syndrome (MDS).
  33. Cage culture: • Panulirus polyphagus stocked in two cylindrical floating net cages. • In cage I 1000 juveniles of weighing 80-120gm (Group I). • Cage II 1500 juveniles of weighing < 80gm (group II). • Result shows that smaller animals in cage II showed higher growth rate than the larger animals in Cage- I which suggests higher growth performance of smaller animals at high stocking density compared with larger animals. Mojjada, et al., (2012)
  34. References: • Manisseri,, K . Marry (1998). Crab and lobster culture. In: Kadalekum Kanivukal (Bounties of the Sea). Ravindran, K and Srinath, Krishna and Kunjipalu, K K and Sasikumar, V, (eds.) CIFT, Cochin, pp. 71-75. • Mojjada, s.k., i. Joseph., k. Mohammed koya., k. R. Sreenath., g. Dash., s. Sen., mahendra., d. Fofandi., m. Anbarasu., h. M. Bhint., s. Pradeep., P. Shiju., g. Syda rao., (2012) Capture based aquaculture of mud spiny lobster, Panulirus polyphagus (Herbst, 1793) in open sea floating net cages off Veraval, north-west coast of India. In: Indian J. Fish., 59(4): 29-34, 2012.
  35. • RADHAKRISHNAN, E. V., (1996). Lobster farming in India. In: Bull. Cent. Mar. Fish. Res. Inst., 1996, 48: 96 – 98. • Vjayakumaran, M., and E. V. Radhakrishnan., (1998) Lobster culture and live transport. In: Proceedings of the Workshop National Aquaculture Week. Sakthivel, M and Vivekanandan, E and Rajagopalan, M and Meiyappan, M M and Paulraj, Rand Ramamurthy, S and Alagaraja, K,(eds.) The Aquaculture Foundation of India, Chennai, pp. 97-103
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