Effects of Chlorpyrifos organophosphate pesticide on haematological indices of Grass Carp Ctenopharyngodon idella (Valenciennes, 1844)

Agricultural pesticides are important chemical pollutants which are extensively used worldwide. In this study, the effects of sub-lethal concentrations of Chlorpyrifos were investigated on haematological parameters of Grass Carp. In the present experiments, first the lethal concentration (LC50) of Chlorpyrifos was calculated, then the effects of different concentration of LC50 (10, 20 and 30 %) were studied on cortisol, glucose, RBC, hematocrit, hemoglobin, WBC and some other blood factors of Grass carp (C. idella) during 14 days. Blood sampling was performed at 12hr, 24hr, 96hr, 7d and 14d and blood factors were measured using standard methods. Result showed that with the increase in pesticide concentration, a significant increase was observed in the concentrations of glucose, cortisol, RBC, Ht, Hb, MCV, MCH and MCHC at 12hr and 24 hr, and then the mentioned parameters decreased at the end of the experiment period. In addition, WBC, lymphocyte and eosinophil significantly increased at high concentrations of pesticide, and monocyte and basophil decreased. According to the results, Chlorpyrifos have shown the intensive effects on physiological and immunological characteristics of the carp. Additionally, blood factors, especially the amount of RBC and WBC, can be introduced as health bio-indicator of Grass carp and aquatic environment.