Larval rearing and production of spat of pearl oyster Pinctada fucata (Gould)

Abstract

The Indian pearl oyster Pinctada fucata was spawned in the laboratory and the larvae were successfully reared to spat setting under tropical conditions. The larve grows through the straight-hinge, umbo, eye spot and pediveliger stages in the pelagic phase before metamorphosing to plantigrade and setting on a substratum as spat, and these stages are described. Large differences were noticed in larval growth within and between four rearing experiments. Isochrysis galbana was used as standard food throughout larval rearing at a cell concentration range 80–350/μl. Spatfall occurred on day 24–32 on a variety of substrata. The highest density of 4.71/cm2 was observed on fibreglass tank bottom. Growth of P. fucata larvae appears to be a step function, and that of spat up to 13 weeks describes a curvilinear form.