Subacute physiological stress induced by phosphamidon on carbohydrate metabolism in midgut gland of prawn, Penaeus indicus.

Midgut gland carbohydrate metabolism of penaeid prawn, Penaeus indicus was studied on acute and acclimation to sublethal concentration of phosphamidon. The midgut gland tissue of acclimated prawn showed inhibited glycolysis with an onset of gluconeogenesis. In general acclimation to sublethal concentration resulted in the elevation of the synthetic phase of midgut gland carbohydrate metabolism.

Impact of methylparathion and malathion on cholinergic and non-cholinergic enzyme systems of penaeid prawn, Metapenaeus monoceros.

The nervous tissue AChE, BUChE and glutaminase activity levels were significantly inhibited, whereas glutamine synthetase activity, acetylcholine and glutamine contents were increased significantly following the sublethal exposure of prawn, Metapenaeus, monoceros to methylparathion and malathion. During OPI exposure ammoniagenesis was triggered by increased deamination of purines and oxidative deamination of glutamate. This results in the hyperammonemia.

Recovery of carbaryl inhibited AChE in penaeid prawn, Metapenaeus monoceros.

The acetylcholinesterase activity in selected tissues of prawn, Metapenaeus monoceros showed a significant inhibition during commercial (CgC) and technical (TgC) grade carbaryl exposure. The rate of inhibition of AChE in nervous and non-nervous tissues is more under CgC over TgC exposure, suggests the involvement of emulsifier system for easy penetration of CgC molecule, which is absent in TgC. A progressive recovery of AChE activity from TgC and CgC induced inhibition was in the tissues within 10 days after the transfer of prawns to toxicant free water i.