Estimation of acute toxicity of bilge water to the African catfish [Clarias gariepinus (Burchell 1822)] juveniles

Abstract

Clarias gariepinus (Burchell) juveniles were exposed to different concentrations (10, 20, 30, 40 and 50%) of bilge water for 96 hrs under laboratory conditions using a renewable static bioassay with continuous aeration to determine its acute toxicity. The LC₅₀ of exposed juveniles was found to be 35.97 ml/L with lower and upper 50 confidence limits of 18.98 ml/L and 30.28 ml/L, respectively. Respiratory disturbance, erratic swimming, loss of equilibrium, lethargies and sudden death were observed in the exposed fish and these varied greatly with increase in concentration of the bilge water. The differences observed in the mortalities of C. gariepinus at varying concentrations were significant (p < 0.05).

Keywords: Bilge water, African fish, Clarias gariepinus, Acute toxicity