Document Type : Research Paper
Department of Fisheries, Tonekabon Branch, Islamic Azad University, Tonekabon, Mazandaran, Iran
Department of Fisheries, Lahijan Branch, Islamic Azad University, Lahijan, Guilan, Iran
Aquatics and Fisheries Research Department, Guilan Agricultural and Natural Resources Research and Education Center, AREEO, Rasht, Guilan, Iran
The study was designed to evaluate the effects of spirulina algae and the acidifying impacts of citric acid on the variation of hematological and immune indices in common carp, Cyprinus carpio. The study was completely random in design with nine treatments, 3 replicates and the control, which included using basic diet without any additives. The treatments included T1: basic diet supplemented with 0.5% citric acid; T2: basic diet supplemented with 0.1% citric acid; T3: basic diet supplemented with 0.2% spirulina extract; T4: basic diet supplemented with 0.3% spirulina extract; T5: basic diet supplemented with 0.2% spirulina extract and 0.05% citric acid; T6: basic diet supplemented with 0.3% spirulina extract and 0.01% citric acid; T7: basic diet supplemented with 0.2% spirulina extract and 0.01% citric acid; and T8: basic diet supplemented with 0.3% spirulina extract and 0.05% citric acid. For this purpose, 270 juvenile carp fish (mean weight: 11.35 ± 1.21 g) were fed with the experimental diets for 8 weeks. At the end of the trials, the number of white blood cells (WBCs), red blood cells (RBCs), Hb, HCT, differential white cells (lymphocyte, eosinophil, neutrophil and monocytes) were measured. The mean volume of red blood cells (MHC), mean concentration of cellular hemoglobin (MEHC) and immune indices of fish blood including Lysozyme, GM, and immunoglobulin were also measured. The results indicated significant differences in certain blood factors (i.e., HCT, neutrophil and lymphocyte) between experimental diet groups and the control (p < 0.05). In addition, certain immune indices in the experimental groups were at healthier levels than those in the control (p < 0.05). Finally, the study showed that spirulina algae combined with citric acid acidifier could enhance the body immune system of juvenile carp fish.