Effect of Lethal Concentration of Commercial Gasoline on Caspian Roach (Rutilus caspicus)

In this study, the mortality effects of commercial gasoline at different tested concentrations were evaluated on the common roach (Rutilus caspicus) and LC۵۰ values for each time period (۲۴, ۴۸, ۷۲, and ۹۶ hours) have been determined. Roach with an average weight of ۳.۱ ± ۰.۴۵ g and lengths of ۴ ± ۰.۲۵ cm were used in this study. After transferring the ۲۰۰ fish to the laboratory, they were kept in tanks of ۱۰۰ liters for one week to adapt them to the experimental conditions. After the adaptation period, ۱۰۰ fish were selected randomly and divided into ۱۴ treatments (۰, ۲, ۵, ۱۰, ۲۰, ۴۰, ۶۰, ۸۰, ۱۰۰, ۲۰۰, ۴۰۰, ۶۰۰, ۸۰۰, and ۱۰۰ ppm commercial gasoline). The treatments were completed in triplicate. The results of this study show that the ۹۶-hour LC۵۰ of commercial gasoline is ۶۰۰.۲ ± ۰.۴۴ ppm and the maximum allowable concentration (MAC) is ۶۰.۰۲ mg/L. The study demonstrates the deadly effects of commercial gasoline on the Caspian roach. Spillage of diesel and gasoline fuels from transport tankers can enter rivers and eventually the marine ecosystem, and reach nursery and spawning areas where it can become a serious threat to fish survival.