MAHIRA PARVEEN
Abstract
Ca rbamates are widely used for pesticide control for agricultural purposes. Among carbamates, sevin has been established as most suitable due to its ability to kill the pests at a very small quantity. The LC sevin to adult fishes, Clarias bat rachus was determined as 5.2 mg/L for 96 hours. On the basis of LC50, fishes were exposed to three sublethal concentrations of sevin i.e.0.5, 1.25 and 2 mg/L for acute period. At the end of the experiment, fishes were killed and the heart was removed. Acetylcholinesterase enzyme activity was determined in heart of control and treated fishes. The percentage inhibition was calculated on the basis of acetylcholinesterase activity in heart of control fishes. Fishes showed 21.93%, 42.00 % and 53.25 % inhibition of heart acetylcholinesterase activity with 0.5, 1.25 and 2 mg/L concentrations. A clear increasing trend in percentage inhibition with the increase in concentration of sevin was observed. The hill plot has been drawn to illustrate the inhibitory capacity of sevin.