Some aspects of experimental culture of the oyster Crassostrea madrasensis(Preston)

Settlement and rate of growth of the oyster Crassostrea madrasensis (Prastcm) wwe studied at the Mulki Estuary, Dakshina Kannada. The breeding season extends from October to May. Peak Settlement of spat takes place during November-December and March-April. Of the several cultch materials tried, oyster shell, used automobile tyres, rigid PVC, lime-coated tiles and asbestos were found to be suitable. Cultch smeared with crude extracts of oyster tissiM supported more spat per unit area than the untreated panels. Tliespjt grew initially at the rate of 2-3 cm per month. Spat transferaed to suspmded wire bag grew faster than the feral ones. The oysters attained^ 7.0 cm shell-height in about 7 months. The size at fiiBt maturity was 12-14 mm for males and 24-26 mm for females^ Study of 4he condition and edibility indicies showed that die best season for harvest is May-September