eng Oriental Scientific Publishing Company Biosciences Biotechnology Research Asia 0973-1245 2016-05-06 9 1 447 450. 9750 article Bilal Ahmad Bhat 1 Imtiyaz Ahmad Bhat 1 Santosh Vishwakarma 1 Alok Verma 2 Geeta Saxena 1 Department of Zoology, Govt. Science and Commerce College Benazir, Bhopal - 462 008, India. Department of Zoology, Govt. College Lateri vidisha - 464 114, India. Dichlorvos, a broad spectrum Organophosphate insecticide is a potential toxic pollutant, adversely affecting the fauna of aquatic ecosystem. The objective of the present work was to evaluate the acute toxicity and behavioral responses of Dichlorvos on Labeo rohita under static conditions. The median lethal concentration of the insecticide was found to be 16.71ppm and one tenth of LC50 (1.67ppm) was studied for sub acute studies. Data obtained from the Dichlorvos acute toxicity tests were evaluated using Finney's Probit Analysis statistical method. Behavioral patterns were studied in lethal (1, 2, 3 & 4 d) and sublethal concentration (1, 5, 10 & 15 d). The test fish showed erratic swimming, increased surfacing, copious mucus secretion, loss of equilibrium and hitting to the walls of test tank before finally sinking to the bottom just before death. Fish under sublethal concentration were found under stress, but that was not fatal. https://www.biotech-asia.org/vol9no1/acute-toxicity-and-behavioral-responses-of-labeo-rohita-hamilton-to-an-organophosphate-dichlorvos/ Acute toxicity; Dichlorvos LC50; Labeo rohita; Behavioral changes