Effects of Acute Nominal Doses of Chlorpyrifos-Ethyl on Some Haematological Indices of African Catfish Clarias gariepinus-Teugels

Static bioassay experiments were conducted to ascertain the acute effects of waterborne chlorpyrifos-ethyl at 0.64, 0.80, 0.96, 1.12 and 1.28 mg L 1 on a freshwater fish Clarias gariepinus after 96 h. The effects were assessed by examining the haematological profile against control. Exposure to chlorpyrifos-ethyl caused a significant dose dependent (p< 0.05) inhibition in haematocrit (PVC) and Haemoglobin (Hb) values. There was also a significant decrease (p< 0.05) of RBCC in 1.28 mg L 1 concentration. The WBCC elevation was significantly dose dependent (p< 0.05) in all concentrations except 0.64 mg L 1. The inhibition of MCH and elevation of MCHC were both Non-Significant (NS), but the inhibition of MCV was significant between control and exposed group (p< 0.05). The results of this study highlight the stress to which freshwater fish are exposed through the uncontrolled discharge of insecticides in the aquatic environment.