A study on some cytochemical properties of white blood cells from Huso huso of southern Caspian sea

The objective was to study on leukocytes characteristics of Huso huso stained by cytochemical stains in order to classify these cells more accurately. The samples were taken from Sturgeon propagation centers in the north part of Iran. 10 fish were selected randomly from each age group (fingerling, 1, 2, 3 and 7 years) and blood samples were taken from caudal vein using syringes with no anticoagulant. Blood smears were prepared immediately and fixed by methanol. The smears then stained using cytochemical staining according to the Sigma- Aldrich instructions. Neutrophils and eosinophils were positive for Sudan black B. Neutrophils were positive for Periodic Acid Schiff (PAS) but eosinophils showed a weak reaction to PAS. In acid phosphatase staining, eosinophils showed a weak reaction and lymphocytes were positive. Neutrophils and eosinophils were positive for peroxidase. Eosinophils, lymphocytes and monocytes showed a weak reaction to α-naphtyl acetate esterase and showed a weak to positive reaction to β- glucoronidase. No heterophil was seen in the Huso huso and neutrophils were regarded as the most phagocytic cells in the speicies.