Abstract:

Five juveniles of Clarias gariepinus were exposed to sublethal concentrations (0, 0.25, 0.50, 0.75 ppm) of Gammalin 20 (Lindane) for 8 days to determine the effects on some hematological variables. The values of PCV (Packed Cell Volume), Leucocyte (Leuc), Haemoglobin (Hb), Platelets (Plt), Red Blood Cells (RBC) and Lymphocytes were significantly reduced (P ≤ 0.05) in all the treatment concentrations. Similar results were obtained with Monocytes (Mon.), Erythrocyte Sedimentation Rate (ESR) and Platelets while White Blood Cells (WBC), Neutrophils (Neut.), Lymphocytes (Lymp.) and Eosinophils (EOS) increased in values but were significant (P ≤ 0.05) in some treatment concentrations. There was a significant reduction of Hb and RBC resulting in macrocytic anaemia of the fish. Time, Concentration and Interaction produced major differences only in the values of WBC while haematological indices such as Mean Cell Volume (MCV), Mean Corpuscular Haemoglobin Concentration (MCHC) and Mean Corpuscular Haemoglobin (MCH) had no definite pattern during the exposure period, however, exposure to sublethal concentrations of Gammalin 20 caused changes in the blood characteristics of C. gariepinus which was not directly related to time and concentration.