In this research, the effects of acute toxicity of Diazinon, a pesticide largely used in Khuzestan sugar
cane farms, on Barbus grypus fingerling (2-3g) was studied in order to determine the 50% lethal concentration
(LC ) in 96 hours. The experiments were both static and standard in which TRC was conducted for 4 days 50
(or 96-h) and water physico-chemical parameters including pH, hardness, dissolved oxygen and temperature
were all controlled. The movement and the behavior of the fish were closely examined throughout the study.
The preliminary experiments to calculate the toxicity range of the final treatments including 7 treatments were
conducted three times. Eventually and based on the results and probit statistical method, 96 h LC50 value for
Barbus grypus was determined to be 6.504 mg/l.The maximum amount of concentration is 1.281 mg/l.