en aquaculture aquaculture پژوهشي Orginal research papers A total of 2,400 Persian sturgeon fingerlings weighing 3.50-3.80 g were fed a diet composed of but different amounts of D-pro probiotics (<em>Bacillus subtilis</em>, <em>B. licheniformis</em> and yeast <em>Saccharomyces cerevisiae</em>). Fish were distributed in fiberglass tanks (1.80 &times; 1.80 &times; 60 cm) each containing 200 fish for 2 months. This research was conducted in Beheshti Sturgeon Hatchery Center, North Iran in the summer of 2016. The mean temperature of the water (21<span dir="RTL">&plusmn;</span>2℃), pH (7.5<span dir="RTL">&plusmn;</span>0.5), and aeration and oxygen concentration (6<span dir="RTL">&plusmn;</span>0.5 mg L^-1) were measured for 60 days. The calculated data were analyzed using one-way ANOVA test. Duncan test was used for comparing the means of the treatment. Results suggest that adding probiotics and yeasts to the diet had a significant impact on the percentages of hematocrit (PCV %), neutrophils and lysozyme (<em>p</em><0.05). In addition, it was shown that the immunoglobulins in the T₁and T₃ increased relatively to the control group. The amount of C₃and C₄ complements were significantly increased by adding various sources of probiotics (<em>p</em><0.05). Moreover, in terms of immune and biochemical parameters of the mucus sample, the interleukin 1 (T₁and T₂) and lectin (T₁and T₃) factors were improved. Also, in mucus samples, alkaline phosphatase and GPX all values measured in treated fish were lower than control group in various levels. These results show that application of two bacilli in combination form plus yeast may provide a better efficacy on the Persian sturgeon immune status. Acipenser persicus, Bacillus licheniformis, Bacillus subtilis, Saccharomyces cerevisiae, Hematology, Immunology 2024 2038 http://jifro.ir/browse.php?a_code=A-10-2825-3&slc_lang=en&sid=1 F. Darafsh darafsh.f@gmail.com 100319475328460035728 100319475328460035728 No Department of Aquaculture and Fisheries, Scienceand Research Branch, Islamic Azad University, Tehran, Iran. M. Soltani msoltani@ut.ac.ir 100319475328460035729 100319475328460035729 No Department of Aquatic Animal Health, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran. H.A. Abdolhay hossein_abdolhay@yahoo.com 100319475328460035730 100319475328460035730 Yes ranian Fisheries Sciences Research Institute (IFSRI), Agricultural Research,Education and ExtensionOrganization (AREEO), Tehran, Iran M. Shamsaei Mehrejan drshamsaie@gmail.com 100319475328460035731 100319475328460035731 No Department of Aquaculture and Fisheries, Scienceand Research Branch, Islamic Azad University, Tehran, Iran.