Determination of diazinon effects on some haematological parameters in rainbow trout, oncorhynchus mykiss

The aim of this study was to determine the effects of diazinon on some haematology indices in rainbow trout. During the four day, 10 rainbow trout were exposed to two different concentration of diazinon, 40% (0.66mg/L) and 80% (1.32mg/L), respectively (LC50 = 1.65mg/L). The values of erythrocytes (RBC), packed cell volume (PCV) and hemoglobin (Hb) were significantly (P< 0.05) decreased. Whereas, leukocytes (WBC) value increased significantly (P< 0.05) and then decreased. The values of mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) were significantly (P< 0.05) increased with diazinon administration. However, the increase in the mean corpuscular hemoglobin content (MCHC) was statistically insignificant (P> 0.05). Lymphocyte decreased significantly (P< 0.05). Neutrophils increased and then decreased significantly (P< 0.05). In conclusion, the changes blood parameteres of the fish exposed to diazinon may be related to decreased immune system.