Effects of cypermethrin on haematological parameters of African freshwater catfish, Clarias gariepinus

Abstract

The effect of cypermethrin on the haematological parameters of Clarias gariepinus was studied using a two factor complete randomised design with five exposure concentrations and a control. The expo-sure time was 14 days in cypermethrin and 14 days in pesticide free water. Blood samples were col-lected and analysed for Packed Cell volume (PCV), Haemoglobin (Hb), Red blood cell count (RBC),Erythrocyte Sedimentation Rate (ESR), platelet count, White blood cell count (WBC), Mean corpuscular haemoglobin concentration (MCHC), Mean corpuscular haemoglobin volume (MCV) and Mean corpuscular haemoglobin (MCH). In most of the exposure concentrations, the values of PCV, Hb and RBC in the exposure (14 days) and withdrawal periods (14 days) for all concentrations were raised above that of control. Exposure to the chemical caused significant changes (p< 0.05) in the haematological parameters. The responses of RBC indices (MCHC, MCV and MCH) varied widely during the periods; but did not differ (p>0.05) at the exposure period. ESR of the fish increased during the exposure period, decreased at the first week of withdrawal but increased in the fourth week. There were no significant differences (p>0.05) in the ESR, leucocrit and oxygen carrying capacity variable at the various concentrations of cypermethrin and exposure period.

Key Words: Cypermethrin, blood parameters, pyrethroid insecticides, Clarias gariepinus