The application of polyunsaturated fatty acids-containing supplements in the technology of sturgeons early feeding

The efficiency of application the PUFA-containing supplements, encapsulated into Artemia nauplii, at the early development stages of sturgeons, on the example of sharp-nosed sturgeon and freshwater sturgeon, was investigated. An enrichment of Artemia nauplii was performed using complex emulsions of polyunsaturated fatty acids S. presso at a dose of 0.5 g/l and Easy DHA Selco at a dose of 0.6 g/l («INVE Aquaculture», Belgium). S. presso, encapsulated into Artemia nauplii, was using within 19 days for Acipenser oxyrinchus feeding, Easy DHA Selco – within 14 days for Acipenser ruthenus feeding. It was established that increased mortality of sharp-nosed sturgeon was observed during the first 10 days of feeding. The highest mortality rates were noted on the 5th day both in experimental group, which was receiving enriched Artemia, and in control group. The sturgeon larvae were dying during 6 days with maximal losses on the 3-rd day. Similar mortality trends in both groups of larvae, fed with enriched and control Artemia nauplii, indicate about common difficulties in the transition to exogenous feeding, that do not related with PUFA-containing supplements, but linked with immaturity of eating behavior and functional mechanisms of sturgeon larvae. The application of enriched with PUFA-containing supplements brine shrimp as live feed during A. oxyrinchus growth leads to an increase of 1.5 times the mass of larvae. Analysis of fatty acid profile showed the growth in content of eicosapentaenoic acid of 1.7 times and docosahexaenoic acid – 3 times. The level of DHA / EPA increased to 1.22 against 0.72, which is set for larvae, reared on unenriched feed. The feeding of A. ruthenus larvae with enriched Artemia though it does not resulted in increase of mass accumulation and significant changes in the fatty acid profile, but allows to decrease the mortality of sturgeon early youth more than in halve. In view of the established trends for growth processes of the studied sturgeon species, the use of enriched Artemia nauplii should begin with 10 days of active nutrition for A. oxyrinchus larvae and with 7 days for A. ruthenus larvae. The received results point out the need to develop the specific technologies of enrichment the live feed with polyunsaturated fatty acids for freshwater sturgeon considering differences in fatty acid composition of it's prelarvae.