RESUMEN
ABSTRACT: The present study was aimed to evaluate the effect of heavy metals on an important tissue of two fish species Cyprinus carpio and Wallago attu, sampled from the Indus river, Mianwali District, Pakistan. The concentration of selected heavy metals Fe, Cr, Cu, and in gills, muscles, kidney and liver was compared with an International standard of food fish. The overall metal concentrations among different weight categories in C. carpio were in the order of Fe > Cu > Cr >. In W. attu the overall accumulation of these metals were, in order of Fe > Cu > Cr > Pb The order of accumulation of metals in gills and muscle of C. carpio was Fe > Cr > Pb > Cu; kidney and muscles of W. attu was Fe > Cr > Cu > Pb; liver Fe > Cu > Cr > Pb. An increasing trend of concentration of iron, copper, chromium and lead occurred with an increase in weight of C. carpio and W. attu. There was a significant difference in the accumulation of heavy metals in different organs of both species (p<0.01). All studied heavy metals except Cr were within permissible limits described by various international agencies like WHO, FAO and FEPA in edible tissues of C. carpio and W. attu.