Effects of cadmium on serum osmolality, ion levels and hematological parameters of tilapia (Orechromis niloticus) were evaluated at different salinities. Serum osmolalities (SOs) in fish unexposed to Cd (0 mg l−1) and exposed to 2.5 mg Cd l−1 were not significantly different at salinities of 0, 5 and 10 g l−1, while at 15 g l−1, SO was significantly higher than at 0, 5 and 10 g l−1. Levels of Na+ and Cl− in serum at salinities of 5, 10 and 15 g l−1 were not significantly different; but were significantly higher than those at 0 g l−1 with and without Cd. In media without Cd, the lowest level of K+ in serum occurred at 15 g l−1 salinity, whereas levels of K+ at 0, 5 and 10 g l−1 were not significantly different. The levels of K+ in Cd-exposed fish at all salinities were not significantly different. At 0 g l−1 salinity, hemoglobin, red blood cells, and hematocrit in Cd-exposed fish were significantly lower than controls. At salinities of 5, 10 and 15 g l−1, levels in control and Cd-exposed fish were not significantly different indicating that higher salinity prevented Cd-induced osmotic imbalance and hematological alterations.
- Oreochromis niloticus
- serum ions