Clams form the major resources in the estuaries. Among the clam resources of the south west coast of Maharashtra, M. meretrix, is one of the major exploited bivalve resources of commercial significance. Seasonal variations are reported in the occurrence of these clams, thus affecting the fishery. The daily as well as seasonal fluctuations in the environmental parameters affect the reproductive development of these clams. Present paper analyses the gonad developments in these clams. From the histological studies of the gonads of M. meretrix, four stages of development could be identified. The stages identified were I) maturing, II) ripe, III) partially spawned and IV) spent / resting. The male to female ratio was 1: 1.19. M. meretrix followed a definite pattern of annual reproductive cycle with a prolonged breeding period, extending from September to January.