Impact of Paraquat on Acid and Alkaline Phosphatase Activity in Indian Major Carp <i>Cirrhinus mrigala</i> Hamilton

Abstract

Paraquat is a non-selective aquatic herbicide used to control nuisance vegetation in aquatic bodies. It potentially causes fish toxicity. The present investigation was undertaken to evaluate alterations in Acid Phosphatase (ACP) and Alkaline Phosphatase (ALP) activity in fingerlings of commercially important Indian Major Carp Cirrhinus mrigala. Both ACP and ALP are popular biomarkers of pesticide toxicity- induced aquatic pollution. 96 hours of acute exposure to LC<sub>0</sub> and LC<sub>50</sub> concentrations and 30 days of chronic exposure to LC<sub>1/20th</sub> and LC<sub>1/10th</sub> concentration of paraquat were studied during the present experiment in selected four tissues viz. gill, liver, muscle and brain to interpret its comparative impact at different effective concentrations on selected target tissues of fish. 30 days of chronic exposure to LC<sub>1/10th</sub> dose of paraquat showed exceptionally highly significant (p<0.001) decline in ACP activity of all four tissues among all other treatment groups when compared with the control. The liver tissue of fishes exposed to both the acute concentrations of paraquat shows an exceptionally highly significant (p<0.001) decrease in ALP activity among all other treatment groups and tissues when compared with control. From the present study, it can be concluded that paraquat-induced decline in ACP and ALP activity in Cirrhinus mrigala can be utilized as a prominent biomarker of aquatic toxicity induced due to pesticides in non-targeted organisms like fish. Paraquat can be potentially considered an aquatic ecosystem hazard leading to severe environmental pollution and eco-toxicity.