A study on biochemical changes in the penaeid shrimp, Metapenaeus monoceros (Fabricius) following exposure to sublethal doses of organochlorine pesticide (endosulfan).

Endosulfan, a broad-spectrum non-systemic organochlorine (OC) pesticide is extensively used to control a wide variety of pests in agriculture, horticulture and public health programmes. Biochemical changes occurring in the metabolically active tissues of gills (GL), hepatopancreas (HP) and muscle (MU) of the penaeid shrimp, Metapenaeus monoceros (Fabricius) on exposure to two sublethal doses (40 and 60 ng L(-1)) of endosulfan were studied for 23 days of exposure (DoE). Sublethal doses of endosulfan significantly (P<0.05) altered the levels of the total protein (TP), the total carbohydrates (TC), the glycogen (GLY), the total free sugars (TFS) and the total lipids (TL) in test shrimps. Concentrations of biochemical components significantly varied with the DoE but were dose-independent (P<0.05). Percent decrease in all biochemical components increased with the progress of the DoE irrespective of the exposure concentrations. The order of percent decrease in the concentrations of the TP, TC, GLY, TL and TFS in different tissues at the end of 23 DoE was found to be MU>GL>HP, HP>GL>MU, MU>HP>GL, HP>MU>GL and MU>GL>HP, respectively. The results of the study revealed that sublethal doses of endosulfan significantly alters the proximate composition of major tissues, particularly the TP levels in the MU tissues thereby reducing the nutritive value of this economically important penaeid shrimp. Since M. monoceros exhibits significant biochemical changes on exposure to endosulfan, this species could possibly be used as biosensor of coastal marine and estuarine pollution by OCs.