Methylparathion: induced alterations in the acetylcholinesterase and phosphatases in a penaeid prawn, Metapenaeus monoceros

Following exposure to 40 mu g/l methyl parathion for up to 5 d, the penaeid prawn, Metapenaeus monoceros, was examined for subsequent changes in acetylcholinesterase (AChE), alkaline phosphatase, and acid phosphatase activities. AChE activity was significantly inhibited in all periods of exposure. Acid phosphatase activity was enhanced in the hepatopancreas significantly after exposure to sublethal concentrations of the insecticide, while alkaline phosphatase activity was inhibited. These phenomena may lead to behavioral changes and alter the physiological and biochemical activities so as to result in death of the organism.