Effect of an Organophosphorus Pesticide on Exposure to the Indian Tiger Prawn, Penaeus Monodon

The present study evaluates the effects of an organophosphorus pesticide (Nuvacron), on the tolerance level, biochemical composition of muscle, total haemocyte count and differential count of the post larval stages of the estuarine prawn, Penaeus monodon. Commercial grade pesticide of Nuvacron 36 % by Hindustan Ciba Geigy LTD (India) were procured from an Agrochemical Store at Kollam, Kerala, India. Live specimens of 12 days old post larvae of P. monodon, selected for the study were collected from Matsyafed Hatchery Centre, Thirumullavaram, Kollam, maintained in the laboratory and acclimatized for about 2 weeks before commencement of the experiment in glass troughs of 2 liter capacity each consisting of 10 prawns. Survival and mortality of the prawn was observed for a period of 96 hours. It is evident from the present study that the insecticide was found to be sensitive to P. monodon and the larval stages cannot withstand higher concentration of it. The LC50 was found to be 0.0000032 %. In the present study the biochemical constituents and the differential haemocyte count showed decrement tendency with the increase in pesticide concentration. Therefore the study will pave the attention for toxicity of Nuvacron and the increasing exposure risk of aquatic flora and fauna to it.