Comparison of Organophosphorous pesticide, Diazinon, toxicity in four native fish of Khouzestan province: Barbus sharpeyi, Barbus grypus, Barbus xanthopterus and Barbus barbulus

In this study the acute toxicity of organophosphorous pesticide in four native fishes of Khouzestan province including: barbus sharpeyi, Barbus grypus, Barbus barbulus and Barbus xanthopterus were investigated. The acute toxicity test was conducted following the Organization for Economic Cooperation and Development (OECD) under static-renewal test. Each fish species exposed to serial dilution of Diazinon in triplicate for 96 hours, daily mortality were recorded and analysed. Lethal concentration to induce 10%, 20%, 50% and 90% mortality after 24, 48, 72 and 96 h exposure were calculated using Probit software. Results showed that Diazinon is toxic for all fish species and the mortality rate enhanced along with increasing Diazinon concentration. Mortality pattern was similar in all fish species. Diazinon 96 h LC50 in B. sharpeui and B. xanthopterus were 1.805±0.12 and 2.775±0.23 mg l-1 which was significantly (P