Testing Lethal Concentration of Lead Acetate on Clarias batrachus, Linn

Indian cat fish Clarias batrachus, Linn. was treated with various concentrations of Lead acetate for 48 hrs . The LC50 determined by straight line graphical interpolation method was found to be 500ppm.The plot obtained is called as “Concentration- response relationship” curve. Similarly, the LT50 of various concentrations were determined by “time-response relationship” curve and found to be 45 days for 25 ppm, 40 days for 50 ppm, 37 days for 75 ppm, 35 days for 100 ppm, 30 days for 125 ppm, 28 days for 150 ppm and 150 days for 15 ppm.. The behavioural changes observed in the experiment includes hyper activity, loss of balance, vertical and downward swimming pattern, frequent surfacing activity convulsion, difficulty in breathing and mucus secretion over the body. No behavioural changes or death were observed in the control group during the experiment. The results of the study showed that, acute lead toxicity severely affects the normal behaviour and results in death.