Dichlorvos is an organophosphate used commercially for the treatment of pests such as bedbug. The present study was designed to investigate the effects of dichlorvos on Clarias gariepinus juveniles using oxidative stress and antioxidant parameters. Fishes were exposed to 2.14 and 4.28mg/l corresponding to 1/10 and 1/5th of 96h LC50 of the pesticide. Each of the concentration was replicated thrice for the purpose of accuracy. The muscle tissues were sampled on day 1, 5, 10 and 15. Results showed concentration and time dependent values across the concentration. The value of catalase (CAT) declined while that of lipid peroxidation (LPO) increased significantly(p<0.05) when compared with the control. Hepatosomatic index (HSI) and condition factor (CF) showed significant differences when compared with the control. The present study revealed that dichlorvos elicits toxic stress even at sublethal concentrations resulting in alteration in the studied parameters which is very evident in the blood, serum and muscle samples. There should be urgent education of farmers and the general public on the dangers of dichlorvos to non-target organisms and the environment.

Keywords : Toxicity, Dichlorvos, Fish, Antioxidant Parameters.