Toxic effect of copper sulfate on gill and liver tissue of Oncorhynchus mykiss

Copper is one of trace elements which is essential for enzymatic reactions and is toxic to fish. But its compounds use for algae control and for prevention and treatment of fish disease. In this study, the effects of copper toxicity (copper sulfate) on gill and liver tissues of Oncorhynchus mykiss, were evaluated. 4 aquariums containing ten fish were used. One aquarium as control group and 3 others exposed to 0.2, 0.4 and 0.8 mg/l copper sulfate. Tissue samples were obtained 24, 48, 72, 96 hours after copper sulfate exposure and processed by Hematoxyline- Eosin staining method. The main histopathological changes observed were lamellar aneurisms in gill tissue and bleeding in central vein of liver tissue. These results suggest that exposure to copper as a heavy metal, has toxic effect on vital organs of fish. These toxic effects are various in different species.