Study on the Sub-Lethal Effect of Nano Zinc Oxide (Nano-ZnO) on Some Hematological Indices of Capoeta capoeta gracilis

Zinc is one of the heavy metals in aquatic ecosystems. Currently, nanotechnology has made significant progress in various industries, in the present study, the toxicity of nano-zinc oxide on the blood indices of Capoeta capoeta gracilis (Capoeta) was investigated.

This research was conducted with concentrations of 0, 5, 20, 100 and 400 mg/L of nano-zinc oxide (Nano-ZnO) for 14 days on 70 Capoeta with a mean weight of 20±5 grams. After the experiment, blood samples were taken from the Capoeta and various blood indices were measured including leukocytes, lymphocytes, neutrophils, eosinophils, erythrocytes, hemoglobin, hematocrit, MCV, MCH and MCHC.  

All blood erythrocyte indices in Capoeta showed significant changes, but leukocyte indices did not change. Also, with the increase of nano-zinc oxide in different treatments, the number of red blood cells, hemoglobin and hematocrit decreased and the number of white blood cells increased in Capoeta.  

With rising the concentration of nano-zinc oxide, the level of hematological adverse effects increased and the concentration of 100 mg/l has the most adverse effects in Capoeta. Nano-zinc oxide causes anemia and disrupts Capoeta's immune system, which may be due to its destructive effects on hematopoietic organs such as the liver and kidney.