Effect of phenanthrene on haematological parameters in olive flounder, Paralichthys olivaceus (Temminch et Schlegel)

Effects of phenanthrene on haematological parameters in olive flounder, Paralichthys olivaceus, were studied by exposing fish to water-borne phenanthrene (0.5, 1 and 2 (mu)M) for 4 weeks. Red blood cell count, haemoglobin concentration, haematocrit levels decreased with increasing exposure time of phenanthrene to the fish. Plasma potassium level increased significantly in the experimental group but the levels of sodium and chloride were significantly decreased compared with control. There was no significant change in plasma magnesium, calcium and phosphate in fish of all treated groups compared with the control. The most profound physiological disturbance in phenanthrene-exposed fish was a decrease in blood osmolality. Malondialdehyde level in the plasma in the phenanthrene group (2 (mu)M) was 1.4-fold higher following 4-week exposure compared with the control group. Acetylcholinesterase activity decreased as the concentration of phenanthrene increased, reaching 65.9% of the control value at the highest dose at the 4th week. A key finding from this study is that olive flounder exposed to phenanthrene at concentrations more than 1.0 (mu)M are likely to experience negative impacts on haematological parameters.