Genotoxic Effects of Dyeing Industry Effluent on a Freshwater Fish, Cirrhinus Mrigala by Chromosomal Aberration Test

Pollution of water resources is a serious and growing problem, despite the existence of relevant legislations. Genotoxic studies on industrial pollutants are very important as they tend to accumulate in aquatic animals. Thus use of aquatic organisms to detect the genotoxicity is very useful in environment monitoring. For this chromosomal aberration test was employed to study genotoxicity caused by dyeing industry effluent on a freshwater fish, Cirrhinus mrigala. Kidney tissue was used for the present study. The 96h LC50 was calculated and three sublethal concentrations 24.48%, 12.24% and 6.12% were prepared. Chromosomal preparations of control and treated fishes were made after 24h, 48h, 72h and 96h of exposure period. Somatic metaphase plate was prepared from control fishes to study normal chromosome complement and compared with aberrated somatic metaphase plates of treated fishes. Chromosomal aberrations included Chromosomal fragmentations (Cf), Ring chromosomes (Rc), Terminal chromatid deletions (Tcd), Minutes (M), Centromeric gaps (Cg), Stickiness (Stk), Clumping (C), Pycnosis (Py), Stretching (Stch) and Pulverization (P). Results revealed that dyeing industry effluent to be potentially genotoxic (p<0.05). Centromeric gaps, Clumping and Ring chromosomes were predominant aberrations observed in all concentrations. Higher concentration (24.48%) and maximum exposure period (96h) induces more chromosomal aberrations. 6.12% and lower than this concentration however can act as safe disposal concentration of effluent to be dumped in rivers. This type of study could be used as criteria for determining genotoxicity caused by industrial effluents, which can be used to avoid its toxic effects on aquatic