Mudcrab has ceased to be an incidental crop in milkfish or shrimp ponds, and is no longer considered a nuisance species which burrows and destroys fishpond dikes. With a new technology, especially on pond design, mudcrab can be successfully grown on its own in brackishwater ponds.
Mudcrab from the wild or from the hatchery may be stocked in brackishwater ponds at a stocking density of 5,000 to 10,000 per hectare. These ponds have to be carefully prepared, including the digging up of trench canals parallel to the dikes when polycultured with milkfish so that crabs do not have to be exposed to high temperatures. In monoculture, trenches are not needed but ponds should be provided with water depth of 80-100 cm. Shelters would also be provided. Gracilaria has been found to effectively provide refuge for moulting and post-moult crabs, thus reducing cannibalism among crabs in ponds. The seaweed must be planted in advance. To prevent escape of crabs, each pond is fenced by bamboo or nylon net, and above the water line, a plastic sheet covers the bamboo support. Trash fish is usually fed, at 10% of crab body weight initially, then gradually reduced to 8% and finally 5%. Water management is based on the tides. Selective harvesting is best. Culture period lasts 4-5 months.
|(1) Prepare the mudcrab pond like you would for milkfish in polyculture system or shrimp for monoculture of crabs. Install nets.
(2) Stock mudcrab juveniles, of size 10-40 g or 5-20 cm carapace breadth, at a rate of 5,000 to 10,000 per ha. It is best to stock monosize crabs to obtain a relatively uniform size at the end of the rearing period.
(3) Care for the stock by regularly changing water following the tidal cycle. When crabs cling onto bamboo supports or nets, water condition is not favorable.
(4) Feed trash fish, snails, and other locally available materials for the carnivorous crab. Broadcast the feed twice a day. An initial feeding rate of 10% of total crab biomass is given, later reduced to 5% as the crabs grow older. They won’t need so much food once their growth spurt passes.
(5) Select and remove marketable size and “fat” crabs several times over the grow-out culture period: >300 g female and >400 g male for pulang alimango or the native crabs, and >400 g female and >500 g male for giant crabs. Selective or progressive harvest minimizes competition for food and space and reduces the incidence of cannibalism.
6) To selectively harvest, scoop up the crabs while they congregate near the pond gate as you let in the water. Crabs swim against the current. Then, use lift nets for the remaining crabs as soon as the water levels off.
(7) To harvest totally after the 120-150 days culture period, drain the pond and catch the crabs manually.
(8) Be careful not to damage the crabs, and keep them moist by placing mangrove fronds in the harvest container and
Agbayani RF. 2001. Production economics and marketing of mud crabs in the Philippines. Asian Fisheries Science 14:201-210
Agbayani RF, Baliao DD, Samonte GPB, Tumaliuan RE, Caturao RD. 1990. Economic feasibility analysis of the monoculture of mudcrab (Scylla serrata) Forsskal. Aquaculture 91:223-231
Baliao DD, de los Santos MA, Franco NM. 1999. Mudcrab, Scylla spp, production in brackishwater ponds. Aquaculture Extension Manual No. 28, SEAFDEC Aquaculture Department, Tigbauan, Iloilo. 14 p
Baliao DD, de los Santos MA, Franco NM. 1999. Pen culture of mudcrab in mangroves. Aquaculture Extension Manual No. 26, SEAFDEC Aquaculture Department, Tigbauan, Iloilo. 10 p
Millamena OM, Bangcaya JP. 2001. Reproductive performance and larval quality of pond-raised Scylla serrata females fed various broodstock diets. Asian Fisheries Science 14:153-159
Mudcrab culture. 1999. A 3-fold flyer downloadable from the SEAFDEC/AQD website
Mudcrab culture. SEAFDEC Asian Aquaculture 19 (3, August 1997): p 10-25
Rodriguez EM, Quinitio ET, Parado-Estepa FD, Millamena OM. 2001. Culture of Scylla serrata megalopa in brackishwater ponds. Asian Fisheries Science 14:185-189
Rodriguez EM, Triño AT, Minagawa M. 2003. Diet and harvesting regimen for the production of mudcrab Scylla olivacea in brackish water ponds. Fisheries Science 69:37-42
Triño AT, Millamena OM, Keenan CP. 2001. Pond culture of the mud crab Scylla serrata (Forskal) fed formulated diet with or without vitamin and mineral supplements. Asian Fisheries Science 14:191-200
Triño AT, Millamena OM, Keenan C. 1999. Commercial evaluation of monosex pond culture of the mudcrab Scylla serrata species at three stocking densities in the Philippines. Aquaculture 174:109-118
Triño AT, Rodriguez EM. 2001. Mud crab fattening in ponds. Asian Fisheries Science 14:211-216
Trino AT, Rodriguez EM, Coniza EB, Juanga BP. 1999. Mudcrab. Aquaculture Extension Manual No. 27, SEAFDEC Aquaculture Department, Tigbauan, Iloilo. 34 p