Among the exploited bivalve resources of India, clams are the most widely distributed and abundant group. The major production centers are Vembanad and Ashtamudi lakes in Kerala, where, the Venerid clam, Paphia malabarica is exploited for export. Hatchery reared larvae of this clam were grown at salinities 10 - 40 %₀ range with an interval of 5 (+ 1) and pH varying from 7.0 -8.5 to study their effect on growth, survival and number of days taken for settlement. The highest growth rate of spat was registered in the salinity range of 30 -35 %₀ and a pH of 8-9. The results of the investigations were tested statistically by one-way ANOVA for getting a comprehensive picture of the effect of these two parameters during larval rearing and spat production. These findings indicate scope for direct application in commercial clam rearing, and also for further understanding the key environmental factors that are involved.

Salinity, pH, larval development, spat production, Paphia Malabarica