AN ASSESSMENT OF THE UPTAKE OF LEAD ACETATE ON Oreochromis niloticus (AFRICAN TILAPIA

Abstract

An assessment of the concentrations of lead acetate in the gills of Tilapia (Oreochromis niloticus) samples
collected from a fishpond in Michael Okpara University of Agriculture, Umudike, Abia State was carried out in
this study. The levels of heavy metal concentration on the gills were relatively higher compared to other body
parts which may be attributed to the fact that the gills are the route of uptake of water (which invariably serves
as the medium of entry). Photomicrography from gills of Oreochromis niloticus exposed to lead acetate showed
prominent secondary lamella with moderate epithelial necrosis and marked congestion of venous sinuses, scant
pillar cells, and mucous cells. Correlations between metal concentrations and fish size were not significant
(P<0.05). Although, the level of bioaccumulation of Lead (Pb) generally did not exceed the safe level for human
consumption. However, the constant presence of heavy metal in concentrations closer to limits (0.2 mg/kg of fresh
weight) should be a reason for concern. The study further advised the populace who constantly consume fish from
polluted rivers to avoid eaten the gills and reduce consumption.