Reproductive cycles of some bivalves from vellar estuary, east coast of India

Abstract

Reproductive cycles of three commercially important bivalves, <i>Meretrix meretrix</i> (L.), <i>M. casta</i> (Chemnitz) and <i>Katelysia opima</i> (Gmelin), have been studied for 1 y (June 1982 - May 1983). All these bivalves have an extended breeding period from Feb. to Sept. and the maturation of gonads takes place immediately after spawning from Sept. onwards through monsoon months. Males are slightly dominant than females and both males and females attain maturity at the same time. Bivalve veligers are more in number during the peak spawning period (March-May) and the spat settlement starts from March onwards. Salinity seems to play an important role in the reproductive cycles.