Abstract
In Lake Maryut, which is the smallest of the shallow, brackish-water lakes fringing the Nile Delta, the concentrations of heavy metals in water were determined in polluted and unpolluted areas, along with other water-quality parameters, and compared with some biochemical constituents of blood serum and the activities of specific serum enzymes in Tilapia zilli, an economically important teleost fish. The water-quality parameters and the concentrations of heavy metals were clearly discernible between sampling locations. In the fish, total serum protein was significantly elevated in fish collected from the most polluted area of the lake, which was also found for the protein globulin fractions. Significant hyperglycemia, hyperlipidemia, hypercholesterolemia, and elevated creatinine levels were also observed in these fish. Except for acid phosphatase, all serum enzymes were enhanced in fish from the contaminated areas compared to those observed in control fish.