Cadmium Accumulation in Different Tissues and DNA Content Alteration in Cat Fish (Clarias batrachus) Exposed to Lethal Concentration of Cadmium

In the present study, the acute toxicity experiment was conducted to evaluate LC 50 of Cadmium chloride (CdCl 2 ) on Clarias batrachus  which was found to be 450 ppm for 96 h. Clarias batrachus (average length of 8.5 ± 0.4 cm and the average weight of 13.5 ± 0.393 g) was exposed to sub-lethal concentration (140 ppm) and lethal (450 ppm) concentrations of Cd for 14 days . The Cd accumulation in tissues of the control and Cd sub-lethal concentration treated catfish was nearly the same, but the highest accumulation was observed in the lethal concentration of CdCl 2 treated fish. The sub-lethal concentration is host friendly. The Cd accumulation of five tissues of Clarias batrachus  exposed to lethal Cd concentration was absorbed in the following order: Kidney>Liver>Muscles>Gills>Bone. Agarose Gel electrophoresis of isolated DNA of muscle tissues of control, sublethal, and lethal concentrations treated Clarias batrachus  revealed that the disappearance of DNA quantity was more in lethal in comparison to control and sub-lethal. Cd is a Geno-toxicant that damages the genetic information within a cell causing mutations, which may lead to cancer. So the discharge of effluents containing cadmium into the water resources may be threats to the environment.