Prawn culture in salt pan areas

fhe Central Marine Fisheries Research Institute has evolved new indigenous techniques for farming prawns on modern scientific lines. iVI/s Motha Brothers, the leading salt producers of Tuticorin, approached the Institute for development of prawn farming in the saline fallow coastal lands adjacent to their saltpans in Veppalodai, north of Tuticorin. Realising the importance of demonstration and dissemination of the technical know-how developed in the Institute, the Institute agreed to develop the farm on a trial basis, and the work was started in early 1986

Crab farming potential in India

Commercial scale mud crab culture is fast developing in the coastal ponds of Andhra Pradesh, Tamil Nadu and Kerala. Countries bordering the Bay of Bengal Regions have given much importance for the development of crab farming in order to increase the production for export market. Fall of wild stock in resourceful grounds have stressed the need for proper management and stimulated mariculture ventures. The common mud crabs are Scylla serrata and Scylla oceanica, the later is widely preferred as it grows to a maximum size of 1.5 kg and will not cause any damage to bunds or fencing arrangements in the culture system. A pcakage of technology for field culturing of crab in coastal ponds as well as for production of seed in hatchery is available and envisage the scope for' the large scale development of crab farming in the country. This paper deals with ' various potentials for the progress of farming, methods of culture, seed production, management techniques, constraints and indicative economic returns of the projects

Mudcrab culture and hatchery

The capture, culture and trade of mudcrab are of increasing importance in the coastal areas of the Indo-Pacific region. Mudcrab is considered as a very expensive sea-food delicacy all-over the world. Widespread interest exists in crab fattening in the countries bordering Bay of Bengal. It is feared that the intensive and indiscriminate fishing of this marine crab and the absence of any management measures may cause a decline in the population. Its reproductive capacity is high. It is possible to culture them in specially designed coastal ponds, pens and cages. Experiments conducted in certain parts of brackishwater regions in India have shown high prospects of commercial culture

The aquaculture of Scylla species in India

Among Portunid crabs, Scylla species are commercially important in aquaculture, capture fisheries and trade, and have created wide interest and high preference in India. Part of the 70,000 ha of brackishwater ponds developed for aquaculture in the southern states of Peninsular India is suitable for conversion to crab farming. Crab culture technology developed in the Central Marine Fisheries Research Institute has recently led to increasing interest in crab farming. Surveys have been conducted to identify resource grounds and seasons for collection of wild seeds. However the inadequate supply of seedstock is a limiting factor in promoting the expansion of the industry. Environmental manipulation strategies have been developed to maintain broodstock and produce gravid females. Further refinements of hatchery technology could meet the demands for seed supply and promote culture activities. Crab production ranged from 1,500 to 2,500 kg•ha-1•crop-1 using different culture methods. Based on the economics of different culture methods, fattening is more remunerative than monoculture and polyculture. Post-harvesting techniques and marketing aspects are discussed. Management measures are highlighted to promote conservation of stock for sustainable yield

Development of prawn culture in Tuticorin area

The coastal zone along Tuticorin in Chidambaranar District of Tamiinadu affords suitable environment for the occurrence, survival, growth and production of commercially valuable prawns. The prospects of prawn culture are discussed in relation to the available resources of land, water and wild seeds as well as the recent developments made In the area. Growth and production of Penaeus indlcus cultured in the salt pan area near Tuticorin during 1985-87 are presented. The results of prawn culture experiments were highly Influenced by the stocking density and also the hydrological features of the culture site Best result In growth (27 mm/4.2 g/month) and production (1347 i^g/ha' crop) was recorded when the stocking was kept at 75 000-80,000/ha. The maximum production of 1,600-1,700 kg/ha/crop was attained in high stocking density, but the period of culture was more. A total production of 10, 407.5 Kg of Penaeus indicus was etiained from 7 ponds of a total area of 4.2 ha by raising 2-3 crops in a period of 26 months and fetched a gross income of Rs, 3,90,161/-. The results of the experiments are highly encouraging for the fast development of semi-intensive farming in the area. Various problems encountered In the development of prawn farming and suggestions for better management practices are highlighted. Information covering the suitable areas for the development of coastal farm, economics of culture, culture operations, the sources of financial and technical aids available in this profitable venture are presented

Seabass Hatchery

The seabass or giant sea perch, Lates calcarifer(Bloch) is an economically important food fish in the tropical and subtropical regions of the Pacific and Indian Oceans

Farming the coastal land at Tuticorin

The seeds of milkfish, fingerlings of mullets were identified. The seeds of the prawn Penaeus indicus were rich in coastal lagoons The young ones of the crab Scylla serrata were available in the tidal flats and mangrove swamp.The temperature of the pond water varied from 27 to 31.5''C. The dissolved oxygen contentwas in the range 3.5-6.0 ml/L and the salinity of the culture site varied from 17 to 50 ppm. Development of a natural ecosystem like site was explained. Experiments on the culture of the mullet L.macrolepis and the milk fish Chanos chanos were carried out in these ponds during the last three years. P.indicus and S.serrata were also reared separately in four ponds. The period of culture was normally 10 months and designed from May-February. The composite culture with compatible species like milkfish and mullet was found to give good results. Monoculture practices done exclusively with milkfish or mullet in rest of the ponds with different stocking intensities have thrown light in determining the optimum stocking level for better yield. Rice bran and ground nut oil cake at the ratio of 2:1 were supplied to the stocks at 5% of the body weight. The predatory fishes were eradicated from the ponds periodically. Different sets of experiments completed were dicussed in detail with results

Mud crab hatchery and fattening

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

Mud crab hatchery technology

The portunid crab Scylla oceanica ts preferred as a candidate for farming and fattening by virtue of its export potential. As wild seed stock is inadequate to meet the growing demand, there has been a concerted effort in countries like Taiwan, Japan and India to develop hatchery technologies for seed production not only for farming but also for sea ranching. Results of experiments on brood stock management, incubation, seed production through larval rearing, live feed production for larval stages, water quality management, crab culture and fattening conducted in tanks at Tuticorin are presented in this paper

A note on the length-weight relationship and relative Condition in Herklotsichthys punctatus (Ruppel)

An analysis of the length-weight data of Herklotsichthys punctatus shows no significant difference between the sexes in the regression coefficient which is found to be very close to 3.0. The relative conditi<Mi in females appears to be influenced both by the feeding intensity and the onset oi maturity whereas in males an improvement in the condition factor coincides with the attainment of maturity