effects of salinity and temperature on the metabolic and immune parameters of the banana shrimp fenneropenaeus merguiensis (de man, 1988)

This study investigated the activities of metabolic and immune enzymes in the hepatopancreas and muscle of the banana shrimp fenneropenaeus merguiensis at different salinities (10, 15, 20, 25, and 30 ‰) and temperatures (21, 24, 27, 30, and 33°c).  the shrimp (mean initial weight, 1.72±0.25 g) were cultured at different salinities or different temperatures for 15 d. all treatments were conducted in triplicate. results showed that glutamic pyruvic transaminase (gpt) and glutamic oxaloacetic transaminase (got) activities in the hepatopancreas were the highest at a salinity of 20‰ (p<0.05). the got and succinate dehydrogenase (sdh) activities in the muscle were the highest at a salinity of 25 ‰ (p<0.05). the got and gpt activities in the hepatopancreas at a temperature of 24ºc were significantly higher than those at the other temperatures (p<0.05). the highest sdh activity in the muscle was observed at a temperature of  27 ºc (p<0.05). different immune enzymes showed different responses to salinity and temperature. the highest superoxide dismutase (sod) activity in the hepatopancreas, and the highest acid phosphatase (acp) activity in the muscles was observed at a temperature of 24°c (p<0.05). by contrast, the lowest acp activities in the hepatopancreas and muscles were observed at salinities of 25 and 20 ‰, respectively (p<0.05). these results indicated that suitable salinity and temperature can increase the metabolic enzyme activities, but the relationship of immune enzymes activities and ambient conditions is indeterminate.