The impact of dietary DHA/EPA ratio on spawning performance, egg and offspring quality in Siberian sturgeon (Acipenser baeri)

Abstract

The effect of different docosahexaenoic acids (DHAs)/eicosapentaenoic acids (EPAs) on the reproductive performance and offspring quality of Acipenser baeri was evaluated in a 6-month trial. Two isonitrogenous and isolipidic diets with different DHAs/EPAs of 1:1.9 and 1.9:1 were designed, and named after high EPA (HE) diet and high DHA (HD) diet. Stocking density was 12 kg/m2, and 136 female fish were randomly divided into two groups of 68 fish per group. After a 6-month feeding period, the hybridization was conducted among maturing female A. baeri and male A. schrencki. The broodstock performance was recorded and 6000 larvae from each group were cultured to evaluate the growth performance. Compared with the HE females, the egg mass weight, fecundity and fertilization rate in HD groups increased 40.8%, 22.3% and 35.6% respectively. Serum estradiol (E2), 11-keto-testosterone and luteinizing hormone (LH) in HD females were significantly higher than those in HE females (P < 0.05). Eggs of females fed HD diet had almost double EPA, DHA and total polyunsaturated fatty acid (PUFA) to HE eggs. Thirty-five-day post-hatching larvae from females fed HD diet tended to present a better growth performance, with higher body length, body weight, weight gain and survival rate than those of larvae from HE group. The results demonstrate that feeding A. baeri female broodstock with high DHA would improve fecundity, egg hatchability, and the overall quality of the larvae.