II Edible bivalves; Mussels and Oysters

Edible sea mussels belonging to the genus Mytilus are fished in quantities on some parts of the Indian coasts and are commercially important. They are bivalves approximately triangular in shape, with a shell pointed at the anterior end, a firm, horny periostracum, and anchoring byssus threads secreted by byssus glands present in the foot. The mussels attach themselves to rocks or other hard substratum by these threads. The mussel resources are rich on the south western coast. When occurring in abundance they form thick carpet-like growths on rocks and concrete constructions like piers and wharves. Large beds of Mytilus colonise concrete and timber structures in ports and harbours. Two species of mussels are represented along our coasts, the green mussel, Mytilus firidis Linnaeus and the brown mussel, Mytilus sp. Mytilus viridis enjoys a wide distribution, occurring on both the east and west coasts and is fairly abundant at Cochin, Malabar and southern coast of Mysore. On the other hand, the brown mussel has a very restricted distribution extending from South of Quilon to Tirunelveli coast (Jones, 1950; Rao, 1958)