Edible Oyster spat-fall at Parangipettai backwaters, South-east India

Abstract

The spat settlement of the edible oyster Crasostrea madrasensis (Preston) was monitored for a period of one year (April 1982 - March 1983) in the backwaters of Parangipettai. Settlement was perennial with peaks of abundance during August (late pre-monsoon) and October (monsoon). Of the six materials lime coated half tiles were the best-spat collector. The decrease in salinity during late pre-monsoon and monsoon periods, probably triggered active breeding resulting in subsequent peak spat-falls. A positive correlation between spat-fall and dissolved oxygen contents of the water was also observed. Concave surface attracted more spat than convex surface.