This present study was carried out to unveil the effect of dichlorvos (a well-known organophosphate insecticide) on adult Clarias anquillaris (Linneaus, 1758) blood cells and enzymes. Twenty-six probe organism (mean weight, 102 0.59 and mean length, 28.02 0.2cm) were acclimatized to laboratory condition for 10 days and then exposed to varying sublethal concentration of dichlorvos (0.20, 0.40, and 0.60mgl -1 ) in a semi static bioassay for 20 days. Blood cells viz: white blood cell (WBC), Red

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... od cell (RBC), haemoglobin (Hb), lymphocytes (Lyp), pack cell volume (PCV), eosinophils (Eos) and Monocyte (mono) were determined in the blood sample while Phosphatases (acidic phosphatase, ACP and alkaline phosphatase, ALP) were determined in the liver. Blood cells (WBC, RBC, Hb, PCV, Mono) values were not statistically significant, however values unveiled a slight demarcation from the control. Mean cell volume (MCV) and Mean cell haemoglobin concentration (MCHC) values also showed a slight demarcation from the control. Phosphatases (ACP and ALP) values were statistically significant. ALP values elevate in a dose dependent pattern while ACP values decreases down the experimental group (not in a dose dependent pattern) . It is concluded that dichlorvos could be toxic at high concentration significantly on the enzymes. Enzymes tested could be very useful biomarker of sublethal effect of dichlorvos than blood cells. Further studies are required to elucidate the potential environmental risk of dichlorvos.