Evaluation of the Effects of (NO₃)₂Pb on Oreochromis niloticus (Pisces, Cichlidae) by Means of Cytogenetic Techniques

Abstract

Water sources contamination is a major concern subject, as well as the environmental presence of a widely diffuse pollutants, as lead. Evaluation of xenobiont effects on genetic material have as a main objective to determine the relationships between genotoxicity and initiation of neoplasic and teratogenic events and genetic diseases. This evaluation can be done by means of several bioassays. Fishes are suitable bioindicators for the detection of aquatic pollution. In this study Oreochromis niloticus specimens were exposed to 2 different concentrations of (NO₃)₂Pb. Chromosome alterations in structure and number, micronucleus test and nuclear morphology alterations were analysed in chromosome preparations and blood smears of exposed and unexposed fishes. Results showed significant differences in the frequency of micronucleus and chromosome alterations between distinct treatments. These data suggest a genotoxic effect of (NO₃)₂Pb.