Environmental pollutants are a major problem for aquaculture. The aim of this study was to evaluate the effects of chlorpyrifos, a pesticide used by agricultural producers in plant production, on some hematological parameters (hemoglobin, hematocrit, erythrocyte, leukocyte, platelet, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) of rainbow trout (Oncorhynchus mykiss) and brown trout (Salmo truttafario). Fish were exposed to CPF concentrations (1 µg/L and 2 µg/L) for periods of 21 days.

In rainbow trout; dosage effects were found very significantly for leukocyte, platelet, MCV and MCHC among hematologic parameters (P< 0.01), whereas dosage main effects were found significantly for other parameters (P< 0.05). In brown trout; hemoglobin, hematocrit, erythrocytes, leukocytes, platelets, MCH and MCHC were significantly affected by the treatments (P< 0.01). In chlorpyrifos applications, the values regarding hematologic parameters showed some differences such as increasing-decreasing and decreasing-increasing. In this study, hematological parameters will be valuable to facilitate as a potential biomarker for assessing the health status of fish.