Histological Lesions in Gills of Feral Cyprinids, Related to the Uptake of Waterborne Toxicants from Keenjhar Lake

Gill epithelium is a major site of gaseous exchange. The aim of the present study was to detect heavy metals content from the gills of L. rohita H., C. catla H., and C. mrigala H., respectively, from Keenjhar Lake water and to evaluate the histological alterations from the gills, due to the accumulation of waterborne toxicants. Heavy metals content was detected via flame atomic absorption spectrometer (FAAS) and electro thermal atomic absorption (ETAAS). The pathologic lesions of the gills included hypertrophy, hyperplasia, fusion of secondary gill lamella, aneurism, hemorrhage, vascular congestion, proliferation, dislocation, hyperemia, and deformities of gill arches. The gills of C. mrigala H. showed extensive range of histological alterations, even elevated heavy metals burden. Heavy metal content from the gill of C. mrigala H. were 3.29, 4.25, 4.57, 4.06, 97.68, 75.06, 10.11, 10.36, and 11.09 g g- 1 dry weight for Cd, Ni, Zn, Pb, Fe, Ca, Cu, Cr, and Co, respectively. Heavy metals content exhibited in Keenjhar Lake water was in descending order as Ca Cu Fe Zn Co Cr Pb Ni Cd; however, Zn, Pb, and Co were higher than permissible limits, while the rest of the elements were below than those of permissible limits recommended by the World Health Organization. Heavy metal content from the gills of cyprinids was variable.