Coastal Aquaculture and Mariculture (2+1)

PERNA VIRIDIS

 

DISTINCTIVE CHARACTERS

Shell large, elongate, sub-trigonal with its anterior end pointed, arched and beak like dorsal margin of shell angularly convex in middle, posterior margin broadly rounded. Ventral margin slightly concave, valves strongly inflated particularly in anterior part. Surface of shell strongly decussately striated. Ligament strong and elongated. Shell surface covered by a firm, horny bright green periostracum.

Attaches to hard substratum by means of longer, thin, flexible byssus threads secreted by byssus glands present in byssus cavity and foot. Foot is much reduced, tongue shaped and has a groove posteriorly which is used like sucker to adhere firmly to substratum. Occurs all along east and west coast of India. Abundant at Kochi, Malabar and north Kerala; found in open coasts, harbours, mouths of estuaries; euryhaline; distributed from low water mark to a depth of 3 m.