Biochemical changes induced by Cartap hydrochloride (50% SP), carbamate insecticide in freshwater fish Cirrhinus mrigala (Hamilton, 1822)

Abstract

The freshwater fish Cirrhinus mrigala was exposed to Cartap hydrochloride (50% SP) for 24, 48, 72 and 96 h. The LC 50 values were found to be 0.436, 0.419, 0.394 and 0.376 mg-1 in static method and 0.399, 0.371, 0.361 and 0.339 mg.L-1 in continuous flow-through system. The static LC50 values are higher than the continuous flow-through method. The LC50 values showed a decreasing trend with an increase in time of exposure in both the methods. The decrease was more in a continuous flow-through method than in the static method. The fish were exposed to sub-lethal (1/10th of 96 h LC50 value 0.0376 mg.L-1) and lethal (96 h LC50 value 0.376 mg.L-1) concentrations of the pesticide for 24 and 96 hours to study the alterations in glycogen, total proteins and nucleic acids (DNA & RNA) contents of various tissues viz., gill, brain, liver, kidney and muscle. Glycogen, total proteins and nucleic acids (DNA & RNA) content values decreased in all the tissues of exposed fish and the per cent decrease is more apparent in lethal concentrations than in sub-lethal concentrations. From the present study, it can be concluded that Cartap hydrochloride caused a decline in the glycogen, total protein and nucleic acids (DNA, RNA) content in Cirrhinus mrigala and the changes are more pronounced in lethal exposure than in sub-lethal exposure.