Effects of diet, stocking density and environmental factors on growth, survival and metamorphosis of clam, Paphia malabarica (Chemnitz) larvae

Abstract

A series of experiments were conducted to evaluate the e¡ects of diet, stocking density and environmental factors on the growth, survival and metamorphosis of short neck clamPaphiamalabarica larvae.These experiments examined the following factors: diet [Isochrysis galbana, Nannochloropsis salina and a mixture of I. galbana and N. salina (1:1 w/w)], stocking density (1, 3, 5 and 7 larvaemL_1), light intensity (unshaded, partially shaded and fully shaded) and water ¢ltration (un¢ltered and sand ¢ltered). Results indicated that N. salina could replace 50%of I. galbana as a food source for the clam larvae with an increase in growth, survival (47.2%), metamorphosis (33.5%) and early settlement. Larval growth decreased signi¢cantly with increasing stocking density. A density of 1^3 larvaemL_1 appeared to be optimal for normal growth of clam larvae