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">The present study examined the effects of dietary thiamine (vitamin B₁) on the physiological performance and egg quality of beluga sturgeon (<i>Huso huso</i>) broodstock. A total of 96 beluga sturgeon broodstocks (mean weight 39.65 &plusmn; 6.01 kg) were randomly distributed to 12 tanks and received diets containing 0 (control, C), 5 (TH1), 10 (TH2), and 20 (TH3) mg thiamine kg^-1 for 24 months. After the feeding trial, plasma sex steroids, glucose-6-phosphate dehydrogenase (G6PD) enzyme activity, reproductive parameters, and the vitamin content of the egg were assessed. Plasma levels of progesterone, testosterone, and 17&beta;-estradiol were significantly higher in the TH3 group than in the others (<i>p</i><<i>‌</i>0.05). G6PD enzyme activity was significantly elevated in the TH2 and TH3 groups compared to the control group (<i>p</i><<i>‌</i>0.05). The control group showed a significant increase in the egg number compared to the TH3 group. The egg diameter significantly increased in the TH3 group (<i>p</i><<i>‌</i>0.05), while working and relative fecundities remained unaffected (<i>p</i>>0.05). Egg vitamin content significantly augmented in all three thiamine-fed groups compared to the control (<i>p</i><<i>‌</i>0.05). This study concluded that dietary 20 mg thiamine kg^-1 improved physiology, ovarian development, and egg quality of beluga sturgeon broodstock.</span></span></span> Egg quality, Great sturgeon, Physiology, Reproduction, Vitamin B1 787 804 http://jifro.ir/browse.php?a_code=A-10-1274-6&slc_lang=en&sid=1 M. Mohseni mahmoudmohseni73@gmail.com 100319475328460059572 100319475328460059572 Yes International Sturgeon Research Institute, Iranian Fisheries Science Research Institute, Agricultural Research Education and Extension Organization (AREEO), P.O. 41635-3464, Rasht, Iran T. Sohrabi t.sohrabi@areeo.ac.ir 100319475328460059573 100319475328460059573 No International Sturgeon Research Institute, Iranian Fisheries Science Research Institute, Agricultural Research Education and Extension Organization (AREEO), P.O. 41635-3464, Rasht, Iran F. Mortezaei mortezaei_faeze@yahoo.com 100319475328460059574 100319475328460059574 No Fisheries Department, Faculty of Natural Resources, University of Guilan, Sowmeh Sara, P.O. Box 1144, Guilan, Iran M.H. Seyed Hassani mirhamedhassani@yahoo.com 100319475328460059575 100319475328460059575 No International Sturgeon Research Institute, Iranian Fisheries Science Research Institute, Agricultural Research Education and Extension Organization (AREEO), P.O. 41635-3464, Rasht, Iran R. Ghorbani Vaghei ghorbani_v2@Yahoo.com 100319475328460059576 100319475328460059576 No International Sturgeon Research Institute, Iranian Fisheries Science Research Institute, Agricultural Research Education and Extension Organization (AREEO), P.O. 41635-3464, Rasht, Iran Z. Pajand zpajand@gmail.com 100319475328460059577 100319475328460059577 No International Sturgeon Research Institute, Iranian Fisheries Science Research Institute, Agricultural Research Education and Extension Organization (AREEO), P.O. 41635-3464, Rasht, Iran A. Yousefi Jourdehi ayoub2222002@yahoo.com 100319475328460059578 100319475328460059578 No International Sturgeon Research Institute, Iranian Fisheries Science Research Institute, Agricultural Research Education and Extension Organization (AREEO), P.O. 41635-3464, Rasht, Iran F. Fadakar Masouleh f.fadakar@areeo.ac.ir 100319475328460059579 100319475328460059579 No International Sturgeon Research Institute, Iranian Fisheries Science Research Institute, Agricultural Research Education and Extension Organization (AREEO), P.O. 41635-3464, Rasht, Iran J. Jalilpour tjalilpoor@yahoo.com 100319475328460059580 100319475328460059580 No International Sturgeon Research Institute, Iranian Fisheries Science Research Institute, Agricultural Research Education and Extension Organization (AREEO), P.O. 41635-3464, Rasht, Iran M. Ghelichpour ml.ghelichpour@gmail.com 100319475328460059581 100319475328460059581 No Inland Waters Aquatics Resources Research Center, Iranian Fisheries Sciences Research Institute, Agricultural Research Education and Extension Organization (AREEO), P.O.139, Gorgan, Iran