
Anthropogenic activities were major causes of stress on natural ecosystems. Pesticides based Agricultural activities have been identified as major contributors to environmental stress, which affects all ecosystem components. The present study was conducted to estimate the toxicity of three pesticides such as Endosulfan, Chlorpyrifos and Carbaryl on the Eye stalk, Thoracic ganglion, Gills of the fiddler crab, Uca triangularis by histological and biochemical analysis. The LC50 (24h) value for Endosulfan, Chlorpyrifos and Carbaryl was estimated at 1.3 ppm, 1.723 ppm and 0.301 ppm respectively. Experimental group of Uca triangularis treated with Endosulfan (1.3ppm), Chlorpyrifos (1.723ppm) and Carbaryl (0.301ppm) showed reduced neurosecretory material and the neurosecretory cells were in distorted condition. The biochemical analysis showed that decrease in protein, carbohydrate, lipid content which was due to enhanced proteolytic activity, glycogenolysis and stress caused by toxicity of pesticides.