Detect of lethal Concentration (LC50-96h) of Arsenic and Cadmium in Roach (Rutilus caspicus)

Due to the increasing entry of various contaminants such as heavy metals into the Caspian sea, research on the effects of heavy metals on aquatic organisms is very important. Among the heavy metals, arsenic has harmful effects on nervous system, digestive system and blood system of aquatic organisms and it is one of important pollutants of Caspian sea. Cadmium can lead the aquatic organisms to death with damaging the tissue, affecting the blood system and genetic and reproduction changing. This study aimed to determine the lethal concentration of arsenic and cadmium on roach(Rutilus caspicus) which has ecological and economic importance in Caspian sea. The test was done with concentrations of 5,10,15,25,35 and 45 mg/l of arsenic and 5,10,15,25,35,45 and 50 mg/l of cadmium in 60Î30Î40cm³ aquarium. Also the control treatment be considered. 7 fishes was added to each treatment. Finaly, the LC₅₀ of arsenic and cadmium at 96 hours were 20/01 and 31/39 mg/l on Rutilus caspicus respectively. According to the results, the sensitivity of roach was considered as moderate in confronting with arsenic and cadmium.