The effect of sub-acute concentration of nano-zinc oxide (ZnO NPs) on hematological indices of Common carp (Cyprinus carpio)

In respect to nano-technological studies and physiological and biochemical lesions of these materials on aquatic animals، in this study we examine the toxicity effects of nano-zinc oxide (ZnO NPs) on hematological indices of common carp (Cyprinus carpio). LC50 of nano zinc oxide was determined according to the mortality at 24، 48، 72 and 96 hours، respectively. During separate experiment based on the LC50 levels، hematological parameters were studied with induction of the sub-lethal concentrations of nano zinc oxide. In this study، lethal toxicity concentration of nano-ZnO (LC50) for common carp was 3. 120 ± 0. 23 ppm. when the fish were exposed to sub lethal concentrations (50% of LC50) for 7days، the results showed that the nano-particles causes various changes in the blood parameters of the fish that these changes was affected by the nano-particles in blood indices by reducing the level of red blood cells (RBC)، Hemoglobin، Hematocrit and increase in white blood cells (WBC) (P<0. 05). In comparison of fish exposed to sub-lethal concentrations of the nano-particles compared to the control group MCHC showed a significant increase (P<0. 05) but during experiment MCV and MCH didn’t show significant changes (P>0. 05) in the exposed nano-ZnO. The results of this study showed that the sub-lethal toxicity of nano-particles could have a negative impact on hematological indices of Common carp، so we should prevent the entrance of such substances to the aquatic ecosystems.