Effects of α-ethinyl estradiol (EE2) and diethylhexyl phthalate (DEHP) on growth performance, antioxidant status and immune response of juvenile yellow catfish Pelteobagrus fulvidraco.

The four experimental groups were carried out to test the response of yellow catfish to EE2 and DEHP: control group was exposed to DMSO; EE2 group was exposed to 1.0 μg/L EE2; DEHP group was exposed to 1.0 mg/L DEHP; mix group was exposed to 1.0 μg/L EE2 and 1.0 mg/L DEHP. The experiment continued for 56 days. Fish survival rate was not different among experimental groups. Fish in DEHP and mix groups had the highest weight gain, and lowest value appeared in control group. The highest hepatosomatic index was found in DEHP and mix groups. Serum alanine transaminase of fish in control group was lower than other groups, but the alkaline phosphatase value was the highest. Serum total anti-oxidation capacity, superoxide dismutase and catalase activities of fish in control group were higher than other groups, but malondialdehyde content is opposite. Respiratory burst and phagocytic indices of fish in EE2 group were the lowest. After 96 h of ammonia stress, the survival rate of fish in mix group was significantly lower than control group. This study indicates that EE2 and DEHP exposure can lead to gain weight of yellow catfish, which is related to liver damage and fat accumulation; EE2 and DEHP exerts its toxic effects by inducing ROS generation, leading to lipid peroxidation and immunosuppression.