Fishery biology and population dynamics of the Marine Crabs portunus portunus sanguinolentus herbst and portunus portunus pelagicus Linnaeus along the Karnataka coast

The marine shellfishes of India is chiefly constituted by crustaceans and \nmolluscs. Among crustaceans, penaeid prawns are most important in view of the \nquantum of landings, value and increasing demand for export trade. These are \nfollowed by crabs and lobsters. \nAlthough there are over 600 species of crabs recorded from Indian waters, \nonly a few of them are being used for food purposes (Rao et al., 1973). The \ncommonly utilised crab species for food in this country belongs to three families, \nviz., Calippidae, Portunidae and Grapsidae.