Growth of pearl oyster Pinctada fucata in the Pearl culture farm at Veppalodai

Abstract

Growth of pearl oyster, Pinctada fucata, under conditions of raft culture at Vcppalodai, Gulf of Mannar, has been studied during the period March 1973- September 1974, with reference to growth of the dorsoventral dimension, hinge line, thickness and weight. The first two dimensions showed positive growth up to a certain period and was followed by growth recession. Thickness increased uniformly throughout the period of study in the younger size groups (30-45 mm) but it showed a stagnation in the older size groups (45-60 mm) during certain times of the year. Weight of oysters increased steadily but showed retardation, except in younger groups (30-40 mm), in a few months. The progress of growth was better in younger size groups than in the older groups. The growth of pearl oysters in the shallow area is considered moderate. Growth was relatively faster during September- January than in other months as observed from the formation of growth processes and growth increments. It has been inferred that the intensity of fouling and boring organisms, b-jsides other factors, might influence the growth of pearl oysters.