Comparative Study of Cadmiumand Arsenic Accumulation in Toothed Carp (Aphanius sophiae)in Fresh and Salt Water

Background: Anthropogenic activities release high concentrations of heavy metals into the aquatic ecosystems, which can be absorbed by the aquatic organisms. In this study, the accu-mulation of cadmium (Cd) and arsenic (As) was compared in liver, gill and muscle tissues of toothed carp (Aphanius sophiae) in fresh and salt water. Methods: A total of 175 fish samples were collected from the Shoor River, Iran during the spring and summer of 2011. Samples were divided into two groups for salt and freshwater ex-periments. The individuals of each group were also divided into seven groups, a control group and the other six exposed to the concentrations of 5, 10 and 20 mg/L of arsenic and 5, 10 and 20 mg/L of cadmium. The liver, gills and muscle tissues of the specimens were dissected. The tissues were wet digested in acid and the concentrations of metals were measured using an ICP-OES instrument. Results: The concentrations of both metals were significantly different in various organs in both fresh and salt water and it were in order of liver > gill > muscle (P <0.001). Based on t-test results, no significant difference was observed between the concentrations of As in related tis-sues of fish cultivated in fresh and salt water. However, Cd accumulation was significantly higher in the tissues of fish specimens cultivated in freshwater (P <0.001). Conclusion: The bioaccumulation of Cd and As depends on organs, metals, and water condi-tion.