Investigation of interactive effect of salinity and ammonia poisoning on some hematology factors and enzymes in oxidative stress reactions of tilapia (Oreochromis niloticus) and common carp (Cyprinus carpio) liver

The present study was designed to investigate the interaction effect of acute and subacute ammonia toxication in different salinity levels (1 and 4 g/l) on oxidative enzymes in in liver of common carp and Nile tilapia. To investigate the interactions, fish were randomly divided into 10 treatment groups (each with three replicates). Temperature, pH and other water quality factors were kept constant during the experiments. At the end of the experiment, catalase (CAT), superoxide dismutase (SOD), glutathione (GSH) and MDA were measured. According to the results, LC50- 96 hours of NH3 was 0.86 and 102.45 mg/l in Nile tilapia and common carp respectively. The results showed that the toxicity of ammonia and salinity in the short term induces antioxidant responses in both fish. Although salinity has an effect on reducing the amount of ammonia in water, but salinity and ammonia levels and their interactions during 96 hours of testing Indicates more stress in common carp than in tilapia.