Susceptibility of Fluvalinate and Esfenvalerate on Adult Tarek <i>Alburnus tarichi</i> (Güldenstädt 1814)

Abstract Fluvalinate and esfenvalerate are pyrethroid insecticides used to control insect pests. These pesticides can enter the aquatic environment in different ways after use, causing toxicity. Tarek is a fish of Cyprinidae family native Lake Van basin Turkey. This study was conducted determine acute toxicity fluvalinate adult tarek. In bioassays, tarek with an average length 20.6±1.2 cm weight 93.9±14.0 g were for fluvalinate, while 19.7±1.2 85.5±16.6 esfenvalerate. Fish exposed using semi-static test method, static method. The tests performed under natural photoperiod. concentrations 0.15, 0.30, 0.45, 0.60 µg L −1 , they 0.33, 0.67, 1.00, 1.34 . at 13±1 °C 96 hours dechlorinated tap water. At end tests, mean lethal concentration (LC 50 ) determined be 0.338 (0.230-0.477) above 0.475 (0.293-0.640) showed toxic effects throughout test, such as splashing, vigorous then slower swimming, loss balance, increased respiratory rate contraction. Consequently, found highly therefore should not exceed 0.003 that 0.005 freshwater environments where lives.