The present work is conducted to evaluate to pathological effect of heavy metal cadmium sulphate in liver of edible fish, Clarias batrachus. Preliminary toxicity tests were conducted to figure out the suitable ranges to be used in the final trials of lethality test. Static bioassays were conducted in the laboratory for 96 hours to determine the median lethal dose of toxicant. The (96-h) Lc-50 for Cadmium sulphate was calculated to be 13.8 mg/l for the present study. 1/10th (1.38 mg/l) of this concentration was used for toxicity tests concentrations . Oedema of hepatocyte with blood congestion in sinusoids was observed after 15 days of chemical exposure. Cytoplasmic vacuolization, pyknotic nuclei, dilation and congestion in blood vessels were noted after 30 days of exposure period, while 45 days of exposure period showed degeneration in the hepatocytes with focal areas of necrosis pyknosis, karyolysis, karyorrehexis with portal tract revealing marked degenerative changes. 60 days of exposure period showed increase in hepatocyte cytoplasmic, pyknosis and hypertrophy of Kupffer cells.
*Dr. Garima Pundir (Wed,) studied this question.