JOURNAL OF THE WORLD AQUACULTURE SOCIETY Vol. 41, No. 4 August, 2010 Effects of Alternative Dietary Lipid Sources on Growth Performance and Fatty Acid Composition of Beluga Sturgeon, Huso huso , Juveniles Seyed Vali Hosseini 1 and Abdolmohammad Abedian Kenari 2 Department of Fisheries, Tarbiat Modares University, PO Box 46414-356, Noor, Mazandaran, Iran Joe M. Regenstein Department of Food Science, Cornell University, Stocking Hall, Ithaca, New York 14853-7201 USA Masoud Rezaei Department of Fisheries, Tarbiat Modares University, PO Box 46414-356, Noor, Mazandaran, Iran Rajab Mohammad Nazari and Morteza Moghaddasi Rajaee Sturgeon Hatchery Center, PO Box 833, Sari, Mazandaran, Iran Seyed Abdollah Kaboli Mazandaran Livestock and Aquatic’s Feed Co., PO Box 643, Sari, Mazandaran, Iran Amelia A. M. Grant Department of Zoology, University of British Columbia, 6270 University Boulevard, Vancouver, BC, Canada V6T 1Z4 Abstract The main aim of this investigation was to determine the impact of a total dietary fish oil (FO) replacement by vegetable oils (soybean [SO] and canola [CO] oil) on the growth and fatty acid (FA) composition of juvenile Beluga sturgeon, Huso huso. Three practical-type diets with equal protein and lipid content were formulated using FO, SO, and CO. Each of the diets was fed to apparent satiation five times daily to H. huso (initial weight 206 ± 7.3 g) for 120 d. All groups grew equally well. Fish weight gain, condition factor, daily growth, feed intake, feed conversion, feed efficiency, protein efficiency, and survival were not affected by diet treatment. Fish lipid composition reflected the inclusion of vegetable oils and their respective FA compositions. Monounsaturated FA and polyunsaturated FA significantly increased in fish fed the CO and SO diets, respectively, but the ratio n − 3/n − 6 were significantly reduced by the inclusion of dietary vegetable oils (P< 0.05). This study suggests that FO can be replaced by SO and CO in H. huso diets under our test conditions with no significant effect on growth. However, longer assessments of these substitutions are warranted to ensure that these treatments do not have an adverse effect on fish health. In the future, aquaculture will contribute more to global food fish supplies and further 1 Present address: Department of Fisheries and Environ- mental Sciences, University of Tehran, Karaj campus, P.O. Box 31585-3314, Tehran, Iran. 2 Corresponding author. help reduce global poverty and food secu- rity (FAO 2001). A major challenge of future aquaculture production is a stable, predictable, and high-quality feed supply. Fish oil (FO) is used as the main lipid source in fish diets to increase their energy content and provide essential fatty acids (EFA). Because of the © Copyright by the World Aquaculture Society 2010 471