Effects of n-3 HUFA content in broodstock diet on spawning performance and fatty acid composition of eggs and larvae in Plectorhynchus cinctus

The effects of n-3 highly unsaturated fatty acid (n-3 HUFA) content in broodstock diets on the quality and fatty acid composition of eggs and larvae were investigated in Plectorhynchus cinctus. Broodstocks were fed a natural diet (trash fish) and four formulated diets with similar proximate compositions but different levels of n-3 HUFA (1.12, 2.40, 3.70 or 5.85%) through their reproductive cycle. Compared with the natural diet-fed group, the egg production per kg of females, percentage of buoyant eggs, survival and length of larvae at 3 days post hatching were similar in fish fed 2.40% and 3.70% n-3 HUFA diets, but markedly decreased in the groups fed 1.12 and 5.85% n-3 HUFA diets. The content of most fatty acids and fatty acid class in eggs and larvae was directly influenced by dietary n-3 HUFA levels and exhibited parallel change pattern with the respective dietary levels. The results showed that either deficient or excess level of dietary n-3 HUFA had a negative effect on egg and larval quality, good spawning performance was obtained when the dietary n-3 HUFA content was 2.40 and 3.70%, or the n-3 HUFA level took 12.17 and 18.63% of the total fatty acids. Dietary n-3 HUFA content may affect egg and larval quality by influencing their fatty acid composition.