Biochemical changes in the fish cirrhinus mrigala (hamilton) after acute and chronic exposure of heavy metal

The use of biological test system for monitoring pollution is gaining importance worldwide by employing toxicity test model with use of a “key species” of fish. The fresh water fish Cirrhinus mrigala (Hamilton) was exposed to the heavy metal Chromium for 24, 48, 72, and 96 hrs, and the consequential LC50 values were calculated using Finney’s probit analysis. Later the fish were exposed to 15, 30 and 45 days acute lethal and chronic lethal concentrations and the biochemical changes of proteins in the vital organs viz, Gill, Brain, Liver, Muscle and Kidney of the test fish were estimated and compared with the control fish. The present study revealed that Chromium is highly toxic to the test fish and the extent of toxicity increased with the increase in the exposure period. In the results of the biochemical changes it was observed that the total proteins decreased in all the tissue of the organs. Maximum accumulation of Chromium was found in the liver and kidney while minimum accumulation was seen in gill. Cirrhinus mrigala, is used as bioindicators because it tends to accumulate heavy metals and so their effects. As the fish is extensively used for human consumption, this finding urges greater regulation for industrial effluent discharge.