en aquaculture aquaculture پژوهشي Orginal research papers <span lang="TR" style="font-size:11.0pt"><span style="font-family:&quot;Calibri&quot;,sans-serif"><span style="color:black">This study investigated the effects of the dietary supplement chitosan (CH) on various parameters including hematological indices, immune response, liver enzyme levels, antioxidant capacity, and the expression of immune-related genes in juvenile starry sturgeon (<i>Acipenser stellatus</i>). 180 juvenile starry sturgeons with an average weight of 31.90 &plusmn; 0.73 g were divided into five feeding groups for 60 days</span></span></span> <span lang="TR" style="font-size:11.0pt"><span style="font-family:&quot;Calibri&quot;,sans-serif"><span style="color:black">includes: control (CTR), 1.5 g (CH_1.5), 3.0 g (CH_3.0), 4.5 g (CH_4.5), and 6.0 g (CH_6.0) of CH powder per kg of a basal diet. Blood analyses conducted after the dietary trial demonstrated that CH significantly increased total red blood cells, white blood cells, hematocrit, and hemoglobin levels, with the highest values recorded in the CH_6.0group. CH enhanced immune responses as evidenced by elevated levels of total protein, albumin, globulin, lysozyme activity, and immunoglobulin, particularly in the CH_6.0 group. Additionally, dietary CH reduced serum lipid levels, and the lowest liver enzyme activities were observed in the CH_4.5and CH_6.0groups. CH also stimulated the activity of antioxidant enzymes, with the most pronounced antioxidant activity noted in the CH_6.0group. Moreover, CH improved the regulation of the relative expression of interleukin-1 beta (<i>IL-1&beta;</i>) and tumor necrosis factor alpha (<i>TNF-&alpha;</i>) genes in liver, intestine, spleen, and head kidney tissues, with the highest expression levels for both genes recorded in the CH_6.0group. These findings suggest that the inclusion of 6 g kg^-1 CH in the diet of starry sturgeon enhances hematological and biochemical parameters, boosts antioxidant capacity and immune response, and supports immune-related gene expression.</span></span></span> Chitosan, Aquaculture, Stellate sturgeon, Inflammatory genes, Real-time PCR 587 606 http://jifro.ir/browse.php?a_code=A-10-5498-1&slc_lang=en&sid=1 D. Zakeri donyazakeri1@gmail.com 100319475328460059168 100319475328460059168 No Department of Animal Sciences and Marine Biology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran J. Pazooki pazooki2001@yahoo.com 100319475328460059169 100319475328460059169 Yes Department of Animal Sciences and Marine Biology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran M. Mohseni mahmoudmohseni73@gmail.com 100319475328460059170 100319475328460059170 No International Sturgeon Research Institute, Iranian Fisheries Science Research Institute, Agricultural Research Education and Extension Organization (AREEO), Rasht, Iran S. Jamshidi jamshidi99@yahoo.com 100319475328460059171 100319475328460059171 No International Sturgeon Research Institute, Iranian Fisheries Science Research Institute, Agricultural Research Education and Extension Organization (AREEO), Rasht, Iran