Abstract

Histological studies in organs like gill, liver, muscle and brain of Cyprinus carpio communis were made to assess tissue damage due to sublethal concentration of heavy metals lead and cadmium after 28 days of exposure. In lead treated gill, disintegration and fusion of primary lamellae, extensive vacuolization with disruption of epithelial lining was observed, whereas on sublethal exposure to cadmium, hyperplasia of branchial arch, vacuolization and congestion of blood vessels were well marked. Metal accumulation was clearly visible in treated liver with degeneration and severe necrosis. Both lead and cadmium treated fish showed marked thickening and separation of muscle bundles with severe intramuscular oedema more pronounced in sublethal treatment of cadmium. Neuronal cell degeneration, swelling of pyramidal cells, vacuolization and dystrophic changes were characteristic features observed in treated brain.

Key words: Lead, cadmium, histopathology, Cyprinus carpio communis.