Studies on the remote setting of two commercially important Indian bivalves

Abstract

The concept of remote setting, which involves transporting bivalve larvae, under moist condition and at 5- 10°C lower than the atmospheric temperture, to distant areas for settlement was tried for thejirst time on two species of Indian bivalves. About 68% of the 'pediveliger' larvae of Indian backwater oyster, Crassostrea madrasensis which were transported at 27±1 °C for 18 hours metamorphosed to settle as spat The post-set survived rates were 66.2% to 73.4% in 30ppt and 71.3% to 87.5% in 15 ppt salinity. Higher settlement rate and post-set swvival was observed in larvae transported under low temperature than in atmospheric temperature. Transportation of late 'umbo' larvae of Indian pearl oyster Pinctada fucata gave high survival rate, but failed to metamorphose as spat