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Crab farming has become an integral part of aquaculture in the country. This practice began in the early seventies when some fishpond operators in Bicol, Visayas, and Southern Tagalog started to culture crab as a subsidiary crop in milk fish or bangus ponds.
The crab species Scylla serrata is the biggest and most important member of the family of edible crabs in the Philippines.
Mud crab, or alimango, is considered a delicacy and has become a popular fare in seafood restaurants. It is sought for its very tasty aligue or ripe eggs in the ovary.
Crabs abound in estuaries, mangroves, swamps and tidal waters, living both as a scavenger and a cannibal.
Breeding and Spawning
The mating period of crabs is usually long. When mating, the female is carried by the male, clasping her with three pairs of walking legs. In this condition, it is very easy to catch them. After five days, the female is finally released by the male. Mating usually occurs for four months, during the period May to September. Prior to that, in April, the females develops eggs or aligue.
Crabs spawn in the sea. The newly hatched larvae called zoea are free-swimming. They are carried by the tide to the coast where they migrate to live-in estuaries, swamps and mangroves. Fertility is very high among females. As much as a million eggs can be laid but mortality is also high because of inclement climatic conditions.
Molting
This is an indispensable stage in the life cycle of crabs. During molting, they shed their covering or carapace. This happens when there is an abrupt increases in the size of their body. After shedding the old carapace, the crab is left with a very soft covering. It becomes an easy prey to other animals and survive, the crab buries itself under the mud until the soft shell hardens.
Culture and Cultivation Methods
Small crabs or crab seeds are caught by fishermen in seashores, swamps and other natural habitats. They are gathered and sold to fishponds operators.
Crabs are raised

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