MUD CRAB CULTURE

MUD CRAB CULTURE Advantages of mud crab culture: Rehabilitation of fisheries Use of abandoned shrimp ponds for crab culture Possible to supply prescribed product ( e.g. size, sex, maturity stages, soft shelled crabs) specifically catering to consumer demand Weaknesses: Absence of proper technology High labour and production cost Lack of seed stock and commercial crab farms. Species suitable for culture: Scylla serrata Scylla tranquibarica Scylla oceanica

Scylla serrata Scylla tranquibarica Scylla oceanica

Culture methods site free from pollution, year round brackish water supply Best salinity is 18-30ppt, temperature 25-30°C Rectangular ponds 0.5 to 1 ha with water depths 0.6-1.0m Shelters - to hide during moulting Canals and trenches also serve as hide outs The ponds are drained and dried; Piscicides are used to remove unwanted fish To prevent crabs from escaping the ponds by crawling over bunds, install nylon net fencing of 1-2 mesh close to the perimeter of the ponds Install plastic sheets along top edge of net fence. nylon net fencing

Introduce water to a depth of 0.6-1.0m One to two weeks after water culture stock the ponds with juveniles of size 30-40g at the rate of 5000-10000 per ha Stock the ponds at the rate of 120 juveniles per square meter Feed with trash fish/Acetes Sort the stock every week and stock 5cm juveniles in grow-out ponds.  

Exchange 10-30% water every spring tide Feed - chopped trash fish, animal waste, snails etc. @ 10% biomass initially and gradually reduce to 6% as culture progresses-twice a day in morning and evening Monitor and maintain optimum water quality. crabs >250g - Selective harvest using scoop nets or traps After 3-5 months when all the remaining crabs have attained marketable size harvest totally by draining the pond and hand picking of crabs.