Hepatotoxicity of lead acetate and mercury chloride on the liver of African catfish

Abstract

This study assayed the potential hepatotoxicity of lead and mercury, administered as lead acetate and mercury chloride respectively in Clarias gariepinus. One hundred and twenty juveniles of the catfish per toxicant were used for the experiment. The test media which was prepared using tap water as solvent was renewed once every 24 hours at the same concentration in a static renewal bioassay. Three concentrations 24 mg/l, 12 mg/l, 6 mg/l of lead acetate and 2.5 mg/l, 1.25 mg/l, 0.625 mg/l mercury chloride, and a control, 0 mg/l were used for the definitive test. Ten fishes were distributed in each fish tank, for each test concentration (including the control) in replicates. The subacute test was conducted for fifteen days. Six fishes were sacrificed from each treatment group and the control every fifth day. The liver of fishes were removed and prepared for histopathological observation. The results showed several histopathological damages ranging from vacuolar degeneration of the hepatocytes, to variably-sized cytoplasmic vacuoles of the hepatocytes. This suggests that lead and mercury are toxic to Clarias gariepinus.