Genotoxic Effects of Mercury in Channa Punctatus

Abstract

In order to assess the effect of mercury on the karyotype of Channa punctatus, the fishes were exposed to mercury in the form Mercuric nitrate at various doses (0.019, 0.038 and 0.075 ppm) for 96, 120 and 144 hours. The karyotype was prepared by standard colchicine, potassium chloride, aceto-methanol, air-dried and geimsa staining technique. It was observed that the percentage of Total Metaphase spreads with Chromosomal Aberrations (TMCA) increased with the enhanced mercury levels and exposure time. Mercury induced structural chromosomal aberrations, which included breaks, fragments, dicentric and ring type chromosomes. The study revealed that just 96 hours of exposure to mercury even to.a concentration as low as 0.019 ppm induces chromosomal aberrations in fish.