Acute toxicity of organophosphate fenitrothion on biomarkers in prawn Palaemonetes argentinus (Crustacea: Palaemonidae).

The effect of the organophosphate fenitrothion (FS) on the non-target freshwater prawn Palaemonetes argentinus was studied. Initially, the 96-h lethal concentration (LC50) of FS was determined in adult prawns. Inhibition of cholinesterase (ChE) in the muscle and hemolymph was assessed. Then, in the hepatopancreas, the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione-S-transferase (GST) were analyzed. Lipid peroxidation (LPO) was also determined in the hepatopancreas. The 96-h LC50 value was 1.12 μg/L. Hemolymph ChE activity showed a significant decrease in exposed prawns to FS compared to the control group, while no significant differences in the muscle were observed between groups (p < 0.05). FS caused a significant increase in the activity of antioxidant enzymes SOD, CAT, and GST compared to the control group (p < 0.02). By contrast, LPO levels were not affected by the pesticide (p < 0.05). These results indicate that P. argentinus is very sensitive to organophosphorus which alter biochemical parameters that are related to antioxidant status. Thus, these parameters could be used as biomarkers for assessing water pollution.