Effects of temperature and salinity on the activities of antioxidant enzymes of juvenile turbot Scophthalmus maximus

Two-factor-intersecting experiment was designed to evaluate the effects of temperature(17,20,23,25,and 28 ℃) and salinity(5,10,20,30,and 40) on mortality and antioxidant enzymatic activities in the mucus,blood,gills and liver of juvenile turbot Scophthalmus maximus.The results showed that the fish had a good ingestion at 17 ℃ and 20 ℃,and salinity of 20 and 30.The activities of SOD,CAT,and GP-X in the mucus,blood,gills and liver were affected by both temperature and salinity significantly(P0.05).Within a certain temperature,lower activities of SOD,CAT,and GP-X were observed at a salinity of 30,increasing as the salinity increased or decreased from the normal salinity of 30.Within certain salinity,there were no regular changes in the enzymatic activities as the temperature increased.According to the changes in enzymatic activity and exosyndrome of life and in the two-factor experiment,it is conclude that 17-20 ℃ is of the optimal temperature,and 20-30 is the salinity for juvenile turbot.