Influence of inorganic lead on the biochemical blood composition of the eel, Anguilla anguilla L.

Yellow eels (Anguilla anguilla L.) with an average weight of 50 g were caught in September in the Aveiro Lagoon on the Portuguese West Coast and kept in aerated aquaria for 1 week before the experiment started. The eels were exposed to an inorganic lead concentration of 300 micrograms Pb/liter for 30 days. Differential white blood cell count showed an increase in the number of lymphocytes in exposed fish. Blood hemoglobin and number of red blood cells per cubic millimeter showed no differences between the control and the exposed fish. Biochemical analyses of blood composition, such as plasma glucose, total plasma protein, total plasma cholesterol, and sodium and potassium plasma, showed no differences between treated and control animals. Plasma lactate levels increased in treated animals compared with those in controls.