ISSN: 0975-8585 January – February 2015 RJPBCS 6(1) Page No. 1219 Research Journal of Pharmaceutical, Biological and Chemical Sciences Effect of Copper Sulphate on Aspartate Aminotransferase (AST) and Alanine Aminotransferase (ALT) Activity in Freshwater Fish Ariopsis seemanni. R Thyagarajan*, Vivek Keshav, G Narendrakumar, M Masilamani Selvam, and V Rameshkumar. Department of Biotechnology, Faculty of Bio and Chemical Engineering, Sathyabama University, Chennai – 600119, Tami Nadu, India. ABSTRACT The heavy metals like Copper, Cadmium etc., act as environmental pollutant and they result in adverse effect on the all the life forms. Many physically and enzymatically changes occurring in the living system. Aspartate aminotransferase and Alanine aminotransferase act as bio-indicators for the environmental toxicants level and tissue damage in many living forms. Quantitative estimation of the AST and ALT activity in liver, gills and muscles tissues of catfish Ariopsis semmani when exposed to different concentrations of copper sulphate (2ppm, 4ppm and 6ppm) was estimated on 5 th , 10 th and 15 th days post exposure. The concentration of the toxicant was directly proportional to the amount of the enzyme that is produced by the fish. Keywords: AST, ALT, Ariopsis semmani, bio-indicators, copper sulphate *Corresponding author