Effects of diazinon on some immunological components of common carp, Cyprinus carpio juveniles

The objective of this study was to examine the immunological effects of diazinon, an organophosphate pesticide, on common carp, Cyprinus carpio juveniles. To this end, fish were exposure to sublethal concentrations of diazinon including 0.1 and 0.2 mg/l for a period of 10 days. The obtained results indicated that diazinon affects the immunological parameters of common carp including lysozyme activity and immunoglobulin (IgM) concentrations. In this regard, the values of lysozyme activity were higher in diazinon treatments compared to control group. In contrast, in diazinon treatments, the IgM concentrations were lower than in control group. There were no significant differences in lysozyme activity between diazinon treatments while IgM concentrations showed a dose-dependent pattern in relation to diazinon concentrations. In conclusion, our results showed that diazinon can suppress the immunity of common carp juveniles through decreasing IgM levels as well as stimulates lysozyme activity.