en Toxicology and polution Toxicology and polution پژوهشي Original research papers <div style="text-align: justify;">Aflatoxins are toxic chemicals that are produced by <em>Aspergillus flavus</em>&nbsp;and <em>Aspergillus parasiticus</em>&nbsp;species of fungi.&nbsp;Aflatoxicosis caused by consumption of aflatoxin-contaminated feeds represents one of the serious diseases in most fish species. Due to the lack of information regarding the effects of aflatoxin B₁ (AFB₁) on farmed <em>Acipenser stellatus</em>, providing practical information for rearing of <em>A.stellatus</em> is imperative. <em>A. stellatus</em> fingerlings with the mean initial weight of 7.90<span dir="RTL">&plusmn; </span>&nbsp;0.12 g were kept in 50 Liter tanks with 10 fish per tank in a one way through water system with well water. Fish were adapted to the rearing conditions. The experimental diets were formulated to contain 1500, 1850, 2300, 2850 and 3500 ppb AFB₁ kg^-1 diet.&nbsp;Two control diets were also considered. Fish were fed each of the experimental diets in triplicate groups three times a day for 52 days. At the end of the experimental period, there were significant effects (p<0.05) on WG%, final biomass, condition factor (CF), specific growth rate (SGR) and survival rates with the increase in aflatoxin levels in diets. There were significant differences (p<0.05) in blood parameters including WBC, RBC, HB and PCV % and also liver enzymes such as AST, ALT and ALP with the increase in aflatoxin levels in diets. 50% of fingerlings perished after 52 days of feeding at the concentration of 3500 ppb AFB₁ kg^-1. The results of this study revealed that <em>Acipenser stellatus</em> was relatively resistant to aflatoxin B₁.<br> &nbsp;</div> Farmed Acipenser stellatus, Aflatoxin B1, Growth, Survival, Liver enzymes, blood parameters 95 108 http://ijaah.ir/browse.php?a_code=A-10-227-1&slc_lang=en&sid=1 J Jalilpour 10031947532846002057 10031947532846002057 No International Sturgeon Research Institute, Agricultural Research Education and Extension Organization (AREEO) Rasht, Iran, P. O. Box: 41635-3464 A Sepahdari asepahdari@yahoo.com 10031947532846002058 10031947532846002058 Yes Iranian Fisheries Science Research Institute (IFSRI), Agricultural Research Education and Extension Organization (AREEO), Tehran, Iran, P. O. Box: 14155-6453 S Kakoolaki bsh443@gmail.com 10031947532846002059 10031947532846002059 No Iranian Fisheries Science Research Institute (IFSRI), Agricultural Research Education and Extension Organization (AREEO), Tehran, Iran, P. O. Box: 14155-6453 H Vahabzadeh habib.vahabzadeh@gmail.com 10031947532846002060 10031947532846002060 No Department of Fishery and Aquaculture, Faculty of Natural Resource, Lahijan Branch, Islamic Azad University, Lahijan, Iran Z Pajand Zpajand@yahoo.com 10031947532846002061 10031947532846002061 No International Sturgeon Research Institute, Agricultural Research Education and Extension Organization (AREEO) Rasht, Iran, P. O. Box: 41635-3464 M Masoumzadeh masomzadeh50@yahoo.com 10031947532846002062 10031947532846002062 No Iranian Fisheries Science Research Institute (IFSRI), Tehran, Iran M Alizadeh ana_alizadeh2003@yahoo.com 10031947532846002063 10031947532846002063 No International Sturgeon Research Institute, Agricultural Research Education and Extension Organization (AREEO) Rasht, Iran, P. O. Box: 41635-3464 S Bazari Moghaddam sbm_274@yahoo.com 10031947532846002064 10031947532846002064 No International Sturgeon Research Institute, Agricultural Research Education and Extension Organization (AREEO) Rasht, Iran, P. O. Box: 41635-3464