عنوان مقاله [English]
Five groups of royal oscar (Astronatus ocellatus) with mean weight of 0.8±0.02 grams were fed for 90 days in 15 aquariums (30 30 40 cm). Their diet contained different levels of cobalt chloride with concentrations of 2.5, 3, 3.5 and 4 milligrams per kilogram of feed. Three replicates were used for each concentration. During the experiment, blood factors including RBC, WBC, glucose and hemoglobin, in different groups were measured and compared with control diet. Results indicated that addition of cobalt as growth promotant, significantly affected RBC no., amount of glucose and hemoglobin in blood in all groups of species comparing those fed with the control diet, having no extra cobalt chloride (P<0.05). The best growth, RBC (0.82+1.69) 106 /mm3, glucose (5.03±129.66 mg/dl) and hemoglobin (1.66±8.01)g/dl were obtained with food 4 milligrams /kgr of cobalt chloride, and the highest WBC (9.0)103 /mL was obtained in diet with 3.5 milligrams/kgr of cobalt chloride. It is concluded that the species fed with most cobalt perforemed better than other fishes considering blood indices.