Acute Toxicity of Hexavalent Chromium on Behavioural Parameters and Histopathology Damages in Freshwater Common Carp, Cyprinus carpio

Water sources of almost all regions in India are carrying the unbearable burden of dangerous pollutants. The release of waste products and anthropogenic wastes run-off has contributed to aquatic pollution. The environment has become a storehouse for chemical pollutant which infiltrate into the aquatic environment, including estuarine, thus immobilizing the aquatic biota, among the heavy metals. Chromium is a heavy metal which has both beneficial and harmful effect on organisms. It is highly toxic and carcinogenic. Many industries are disposing of chemical pollutants to the water. These disposals contain many chemicals, including Chromium. The purpose of this review was to check the accumulation and concentration of heavy metals in different organs of freshwater fishes that come in contact with the water contaminated with heavy metals. The subjected fish were exposed to Chromium (Cr) at the sub-lethal level at a concentration of 40mg/L in 96 hours. During the observation period, the fishes shown some behavioral changes like erratic swimming, slow motility, suffocation, and the scales become thin and decolorized. In the gill region, the gill filaments become swollen, and gill rackers become thick, and curling of lamellae was noticed, and it is caused due to the Chromium build-upon gills. At the region of the caudal fin, permanent bending of the tail was observed. The Chromium also affects other vital organs like the spleen and gut region. LC50 was found in 96 hours. The result indicates that Chromium is highly toxic and has deleterious effects on aquatic life. Humans are also affected by the intake of fishes for primary people of those areas where the leading food is fish.