Pearl oysters of the genus Pinctada occur in different
environments, from the intertidal zone to shallow
coastal waters as well as at depths of 12-23 m as on the
pearl banks of Gulf of Ma:nnar. A knowledge of the
physiological characteristics of pearl oyster is necessary
for successful rearing in the farm as well as for production
of quality pearls. Realising this, several
studies have bsen carried out on the physiology of
Pinctada fucata of the Japanese seas. Itoh (1976) has
studied the relation of oxygen consumption and
ammonia nitrogen excreted in the adult oyster to body
size and water temperature
