Histopathological Alterations in Gills , Liver and Kidney of Common Carp , Cyprinus Carpio L . Exposed to Lead Acetate

| The current study was undertaken to investigate the histopathological alterations of gills, liver and kidney in common cap, Cyprinus carpio exposed to lead acetate [Pb(CH3COO)2] for a period of 60 days (LC50 4.24 mg l-1). For this rationale, a total of 100 fish were divided into five treatment groups: control group (untreated); T1 exposed to 0.21 mg l-1Pb; T2 were exposed to 0.21 mg l-1Pb; T3 were exposed to 0.42 mg l-1Pb; T4were exposed to 0.42 mg l-1. During the period of experimental exposure, water was changed regularly at 24 hr intervals with the same amount of the toxicant (stock solutions) except for T1 and T3 the water was replaced daily without adding toxicant. The main histopathological changes caused by Pb observed in gills of T4 were edema in the filamentary epithelium, lifting of lamellar epithelia, hyperplasia of the epithelium with fusion of adjacent lamellae and necrosis in primary and secondary lamellae. The changes are lesser in extent in gills of T1, T2 and T3. The hepatic alterations were more evident in fish exposed to higher concentrations (T4) were cytoplasmic vacuolation, hepatic necrosis with piknotic nucleus. Kidneys exhibited increasing degrees of damage in the tissues in association with Pb concentration, the main alterations were observed in kidney of T4 which including: hydrobic degeneration and necrosis of renal tubules with nuclear piknosis. It can be concluded that gills, kidney and hepatic alterations as a consequence of lead exposition of fish could be act as a sensitive bio-indicator for the toxicity of sub-lethal concentrations of heavy metals as well as other of anthropogenic origin.