Effect of temperature lethal concentration (LC50 96-h) of Cypermethrin on the Caspian kutum fish Rutilus frisii Kutum (Kamensky, 1901)

In this study, the acute toxicity of Cypermethrin insecticides on caspian kutum fry (Rutilus frisii Kutum Kamensky, 1901) with the weight of 3 ± 1 g (average ± SD) in three different temperatures (15 °C, 20 °C and 25 °C) measured. The aim of this study was to determine the lethal concentration of 50 % of fish population within 96 hours. According to O.E.C.D standard methods, Experiments conditions were static and lasted for 4 days (96 h). Water physico-chemical parameters such as pH, total hardness, dissolved oxygen and temperature mesearued During the experiment. To find out cypermethrin cytotoxic range, 10 sea kutum fry were placed in each 20 Litre aquarium and aerated during the experiment. After obtaining leathal concentration final experiment started with 6 treatment and 3 repeatation. The values of LC10, LC30, LC50, LC70, LC90 and LC99 at 24, 48, 72 and 96 hours for all three temperature treatments obtained By using probit analysis, and Cypermethrin acute toxicity (LC50 96-h) for caspian kutum fry at 15 ± 1 ºC, 20 ± 1 ºC and 25 ± 1 ºC was 1.54, 1.49 and 1.30 micro grame per Litre, respectively. Results showed that by increasing the temperature Cypermethrin toxicity increases and also more deaths occur. In this experiment, the Clinical signs such as caudal region bruises, abnormal breathing and fish irregular swimming observed.