Effects of dietary n-3 HUFA concentrations on spawning performance and fatty acids composition of broodstock, eggs and larvae in yellowfin sea bream, Acanthopagrus latus

We conducted a study to investigate the effects of dietary n-3 highly unsaturated fatty acid (HUFA) concentrations on spawning performance and fatty acids composition of broodstock, eggs and larvae of Acanthopagrus latus. Broodstock were fed three isonitrogenous formulated diets with different ratios of fish oil (FO) and sunflower oil (SO) including FO (100% fish oil), FSO (1:1 fish oil: sunflower oil) and SO (100% sunflower oil) as lipid sources with different concentrations of n-3 HUFAs (6.67, 4.26 or 2.92%, respectively) for 132 days. Results show that the relative fecundity, percentage of buoyant eggs, hatchability, survival rate of larvae at 3 days post hatching (DPH) and starvation tolerance test were all higher in broodfish fed FO diet and significantly (P < 0.05) decreased in the groups fed FSO and SO diets. Fatty acids profiles of carcass, liver, eggs, hatchling and 3DPH larvae reflected profiles of the corresponding dietary treatments. In general, increasing concentrations of dietary fish oil lowered deposition of linoleic acid (LA), linolenic acid (LNA) and total n-6 PUFA in all samples and simultaneously improved deposition of docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and arachidonic acid (AA) in all samples, which probably affected spawning performance. The best spawning performance was obtained when fish oil was used alone as the dietary lipid source with 6.6% dietary n-3 HUFA concentration. The results of this study show that the n-3 HUFA concentrations of lipid in broodstock diet has a considerable effect on the quality and fatty acids composition of egg and larval in A. latus.