Salinity regulates antioxidant enzyme and Na+K+-ATPase activities of juvenile golden pompano Trachinotus ovatus (Linnaeus 1758)

Effects of salinity on the growth, survival, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) and sodium-potassium adenosine triphosphatase (Na+K+-ATPase) activities of juvenile golden pompano Trachinotus ovatus were studied under a laboratory condition. Experimental fish were reared at the salinities of 10 parts per thousand, 18 parts per thousand, 26 parts per thousand and 34 parts per thousand for 30 days. Growth and survival of juvenile golden pompano were significantly affected by the rearing salinity. Fish reared at 34 parts per thousand achieved the highest specific growth rate, while the highest survival was obtained when fish were cultured at the salinity of 26 parts per thousand. The highest GPX activity was obtained when fish were cultured at 26 parts per thousand, and the lowest GPX activity was observed when fish reared at 34 parts per thousand salinity. The SOD activities of fish reared at 18 parts per thousand and 34 parts per thousand were significantly higher than those reared at 10 parts per thousand and 26 parts per thousand. The lowest of Na+K+-ATPase activity was obtained in fish reared at 34 parts per thousand, while the highest Na+K+-ATPase activity was obtained when fish reared at 18 parts per thousand. Results from present study indicate that juvenile golden pompano can be reared above 18 parts per thousand without sacrificing fish survival, and the best growth can be achieved when fish is reared at the salinity of 34 parts per thousand. The salinity of 10 parts per thousand may be too low for juvenile golden pompano as the growth, survival and SOD activity were reduced.