No abstract

Aim: Methodology:Results: Interpretation:The present study investigated some important functional responses to salinity stress in Slipper cupped oyster from Setiu Wetlands, Terengganu, Malaysia.Slipper cupped oysters were subjected to different salinities of 7, 14, 28 and 35 ppt for 2 weeks. Total haemocyte count (THC), phagocytic activity, ionic absorption, total protein concentration (TPC), superoxide dismutase activity (SOD) and histological changes of the oyster tissues were determined after 2 weeks of experiment.THC significantly decreased at 7 ppt but increased at 35 ppt (p<0.05). The phagocytic activities were however not affected. The SOD a c t i v i t i e s w e r e significantly higher (p<0.05) at 7 and 14 ppt compared with 28 and 35 ppt. Higher TPC were also observed at 2 8 a n d 3 5 p p t . P o t a s s i u m i o n concentration (mmol l ) increased gradually with the increasing salinities. Salinity s t r e s s w a s a l s o a s s o c i a t e d w i t h histological changes in the gills and digestive gland tubules of the oysters.The present study has revealed the functional r e s p o n s e s o f to salinity changes, and the negative impact of low salinities on the oyster immune system.