Pesticides are one of the most important factors threatening the ecosystem of the Caspian Sea. Due to prevalence of gastrointestinal cancer in Northern provinces of Iran and the possible involvement of pesticides in this case, genetic toxicity of fipronil insecticide on the liver of the Caspian white fish (Rutilus kutum) was studied. Twelve Caspian whitefish fingerlings (five groups including control and treatment groups) were exposed to environmental concentrations of fipronil (0.1, 1, 5 and 10 µg/L) to evaluate the effects of this pesticide on the DNA of fish liver cells. After 14 days of exposure, liver samples were taken. The samples were converted to separated cells after mincing, centrifugation and filtering through the cell strainer, and then dispersed on the slides coated with low melting agarose. After electrophoresis, the slides were stained with SYBRGreen. CellProfiler software was used to analyze the comets. The results showed that increasing the environmental concentration of fipronil increases the damage to DNA. In general, this study showed that fipronil has the potential of damage to DNA and can be considered as one of the factors reducing the survival rate of Caspian white fish fingerling and larva, and possibly expanding the cancer in Northern provinces of Iran.
