Pesticides are used to control pests of food crops, due to their enormous usage, water bodies are continuously polluted.Endosulfan is an organochlorine pesticide, known to be highly toxic to aquatic life, causing behavioural to biochemical pathology in fish. Blood is a pathophysiological reflector of whole body and therefore, blood parameters are an asset in diagnosing the structural and functional status of body organs exposed to toxicants. The aim of this study was to investigate the effect of sublethal concentration of endosulfan on haematological parameters of Etroplus suratensis. Exposure resulted in microcytic-hypochromic anaemia in the fish. The extent of microcytosis was significant and progressive up to 96 h post-exposure and it persisted to a lesser extent during further exposure. Mean corpuscular haemoglobin was significantly and progressively lowered with period of exposure from 24 h post-exposure onward causing hypochromia. At 24 h post- exposure, even though microcytosis was significant, MCH, and therefore, CI was unaffected suggesting the occurrence of microcytic normochromic anemia at the onset of exposure. The changes during exposure were fast recouped once the fish was relieved of the presence of the toxicant.

Keywords : Toxints, Pesticides, Haematology, Fish.