Toxicological impact of detergent effluent on juvenile of African Catfish (Clarias gariepinus) (Buchell 1822)

摘要

The toxicity of commercial detergent effluent (containing Linear Alkylbenzene Sulfonates), ahousehold cleaning agent was investigated with emphasis on histopathological effects usingJuvenile African mud fish (Clarias gariepinus) with the mean weight 1.7 ± 0.2kg and standardlength of 8.3 ± 0.3 cm. After series of range finding test, the fishes were exposed to lethalconcentrations 0.00 mg/L, 0.01 mg/L, 0.02 mg/L, 0.03 mg/L, 0.04 mg/L and 0.05 mg/L and as wellas sub-lethal concentrations 0.000 mg/L, 0.002 mg/L, 0.003 mg/L, 0.004 mg/L, 0.005 mg/L and0.006 mg/L of detergent effluent for 56 days in a renewal bioassay procedure. The median lethalconcentration (LC50) values for lethal and sublethal tests were 0.0166 mg/L and 0.0038 mg/Lrespectively. Respiratory disturbance, erratic swimming, loss of equilibrium, lethargies andsudden fish death were observed in the exposed fish and these varied greatly with differences inconcentration of the toxicant and this shows that mortality increases with an increase inconcentration. The differences observed in the mortalities of C. gariepinus at varyingconcentrations were significant (p < 0.05), an indication that mortality could be a factor ofconcentration and time of exposure. The liver of the control fish showed normal parenchymaappearance of hepatocyte with normal staining patterns of the cell. In the treated fishes, therewas congestion of central vein, vacoulation of hepatocyte, oedema, cellular infiltration and cellularnecrosis. Detergent effluent is highly toxic to Clarias gariepinus juveniles, which are moresusceptible to this household cleaning agent’s effluent; therefore, an indiscriminate discharge ofthis effluent to the surrounding should be discouraged