Effect of different levels of n-3 HUFA on larvae culture performances of Beluga (Huso huso) fish

The effects of n-3 highly unsaturated fatty acids (n-3 HUFA) were studied on Beluga (Huso huso) fish larvae by feeding fish larvae with live food  enriched with 4 different oils (ICES 30/4, tuna eye oil, flaxseed oil and linseed oil) containing different levels of n-3 HUFA including 27.19, 20.33, 12.71 and 0.39 mg g-1 dry weight of oil, respectively. Fish larvae weighing 30.00±2.00 mg were randomly divided into 12 groups of 150 fish each and triplicates fed the 4 experimental diets for 3 weeks. There were no differences in survival rates, but significant differences were found in growth rates and fatty acid composition of the fish larvae after 30 days. Fish fed low levels of dietary n-3 HUFA (0.39 mg g-1 DW) showed poor n-3 HUFA contents but these fatty acids improved with the elevation of the n-3 HUFA levels in the diet up to 20 mg g-1 DW. Fish fed the flaxseed oil showed the highest level of crude lipid 15.00±3.01). Results showed that tuna eye oil and ICES30/4-enriched live food (4.83 ±1.29 and 4.61 ±0.99 mg g-1 DW, respectively) showed the highest n-3 HUFA content for sturgeon fish larvae.