A. Zahmatkesh - Aquaculture Department, Gilan Agricultural and Natural Resources Research and Education Center, AREEO, Rasht, Iran
K. Karimzadeh - Department of Marine Biology, Lahijan Branch, Islamic Azad University, Lahijan, Iran
M. Faridnia - Department of Marine Biology, Lahijan Branch, Islamic Azad University, Lahijan, Iran

The present study was conducted to investigate the protective effects of selenium nanoparticles (nano-Se) and chitosan oligosaccharide (COS) against the malathion-induced blood hematological and biochemical alterations in Caspian roach (Rutilus caspicus). The fish treated with ۰.۵ mg L-۱ malathion in water and supplemented with selenium nanoparticles (۱ mg kg-۱) and /or COS (۶۰۰ mg kg-۱) in their diet for ۲۸ days. At the end of the experiment, the blood samples were collected and hematological indices were assayed including serum total protein, albumin, globulin, glucose, cholesterol and triglyceride as well as enzymes such as aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), alkaline phosphatase (ALP) and acetyl cholinesterase (AChE). Significant decreases were observed in LDH level, AChE activities and hematological indices such as the white and red blood cell count, hemoglobin and hematocrit levels of the fish exposed to malathion (p < ۰.۰۵). Dietary selenium nanoparticles and COS could significantly (P < ۰.۰۵) reduce hematological indices, lysozyme value and the blood antioxidant enzyme activities in malathion-exposed Caspian roach. Briefly, this suggests that supplementation of dietary Caspian roach with nano-selenium (۱mg kg-۱) and /or COS (۶۰۰ mg kg-۱) may have positive effects on hematological and biochemical indices in fish exposed to malathion stress.

Biochemical markers, Nano Selenium, Pesticides, Caspian roach, Stress enzymes