Histopathological Effects of Cadmium Chloride on Liver and Gill of Chondrostoma regium

Aquatic environments received huge amount of pollutants such as heavy metals, hydrocarbons, pesticides and organic materials every day. In this study, the effect of dissolved cadmium chloride on liver and gill in Chondrostoma regium was investigated. For this purpose, one hundred fishes were caught by sein net from one of the branches of Zayandeh Roud and transferred to the laboratory. The experiments consist of four treatments including: control group (without cadmium), 0.5, 2.5 and 7.5 µg/l cadmium concentrations. For histopathological studies liver and gill were performed at the end of experiment the samples were fixed in 10% formalin.The highest rate of cadmium concentration was observed in gill at 7.5 µg/l of cadmium equivalent. Hyperplasia, clubbing and fusion were the main gill histopathological changes. Congestion, nuclear psychosis and necrosis were the main liver histopathological signs. Intensity of gill and liver damages showed increased trend in a dose dependent manner.