Observationts on moulting of crab Portunus pelagicus Linnaeus reared in the laboratory

Young crabs of Portunus pelagicus of the size group between 11 and 44 mm in carapace width were collected from the inshore waters off Mandapam and were reared. Crabs measuring between 11 and 25 mm in carapace width attained marketable size of 140—145 mm at the twelfth moult after a period of fourteen months. Moulting occurred frequently in the young crabs measuring between 11 and 75 mm and thereafter, the interval between the two successive moults increased. The weight of the reared crabs at different sizes was comparable to that of freshly caught from the sea. Regeneration of chelipeds and legs was studied in P. pelagicus by removing a single appendage at one time. After about 4 to 7 days rudiment appendage was found to develop from the basis and it completely regenerated to normal size at the next moult.