Rashid Alijani - Department of Marine Biology, Faculty of Marine Sciences, Khorramshahr University of Marine Science and Technology, P.O. Box ۶۶۹, Khorramshahr, Iran,
Ardeshir Abdolali Movahedinia - Department of Marine Biology, Faculty of Marine Sciences, Khorramshahr University of Marine Science and Technology, P.O. Box ۶۶۹, Khorramshahr, Iran,
Ebrahim Zabihi - Cellular and Molecular Biology Research Center, Health Research Institute, Babol University of Medical Sciences,Babol, Iran,
Negin Salamat - Department of Marine Biology, Faculty of Marine Sciences, Khorramshahr University of Marine Science and Technology, P.O. Box ۶۶۹, Khorramshahr, Iran,

Fipronil is a relatively new insecticide in agriculture with health and environmental effects. This is the first report studying effect of fipronil on fish administered via intraperitoneal route. Intraperitoneal LD50 of fipronil in 16.3 gCaspian kutum, Rutilus frisii kutum, fingerlings was determined using a total of 133 fish in 19 tanks (7 fish/tank) including one control and 6 treatment groups (300, 450, 550, 650, 750, 850 mg/kg). Fish were injectedintraperitoneally and monitored at 96 h. The LD50 of fipronil was 632 mg/kg in Caspian kutum. Sub-lethal test doses of 10, 20, and 30% of the LD50 at 96 h were used to assess the effect of fipronil on the fish’s liver. The blood plasmaof 90 fish were used (18 at each test dose and in controls) on days 7 and 14 for biochemistry. The hepatosomatic index (HSI) of the livers were obtained and histopathology done on the same days. Pyknosis, sinusoid dilation andvacuolization were common histological changes, and these changes became more severe in a time and dose ependentmanner. This dependence was also observed for HSI and the liver biochemical test (alanine and aspartate transaminase). Liver histological alterations showed that fipronil can be a potential factor in liver carcinoma

Caspian Sea; Fipronil; Rutilus frisii kutum; Hepatosomatic index; intraperitoneal route