Lead accumulation in and its haematological effects on African catfish Clarias gariepinus

Abstract

Young adult Clarias gariepinus exposed to 0.0015–0.1500 μg l⁻¹ concentrations of lead (Pb²⁺) ions for 30 days were investigated for accumulations in muscle, gill, liver and heart tissues, as well as for the metal's effects on haemoglobin concentrations, erythrocytes sedimentation rate, packed cell volume, white and red blood cell counts and differentials including lymphocyte, neutrophil, monocyte, basophil and eosinophil counts. The accumulation of Pb²⁺ ions was dose-dependent and highest in the heart tissue. Accumulation also differed markedly in the muscle, gill and liver tissues. The 0.015 μg l⁻¹ toxicant concentration induced significantly higher lymphocyte cells, the 0.1500 μg l⁻¹ concentration induced significantly lower neutrophils, and the 0.0150 and 0.0015 μg l⁻¹ concentrations induced significantly lower monocyte cells than the control. The Pb²⁺ ions induced lowered antibody production. The catfish exhibited an ability to respond to pollutant stress.

Keywords: aquatic toxicology, bioaccumulation, ecotoxicology, heavy metals, metal accumulation