Effects of dietary highly unsaturated fatty acids and astaxanthin on the fecundity and lipid content of pond-reared Penaeus monodon (Fabricius) broodstock

Five diets that contained fresh squid meat as the basic constituent and were supplemented with different amounts of highly unsaturated fatty acids (HUFA) and astaxanthin were fed to pond-reared Penaeus monodon broodstock. Diet A was sole squid meat. Diets B and C were supplemented with astaxanthin 50 and 100 mg kg(-1) respectively. Diets D and E were supplemented with HUFA 5 and 10 g kg(-1) and astaxanthin 50 mg kg(-1) respectively. The result showed that the group fed diet E had the best reproductive performance in all experimental groups. It had a higher proportion of spawns (71.5%), spawning rate (0.047), a shorter latency period (7.7 +/- 0.3 d), higher absolute fecundity (x 10(3)) (361.6 +/- 5.5) and egg production/female (x 10(3)) (597.0 +/- 18.0) than all the other experimental groups. The fatty acid composition in broodstock diets strongly affected the tissue and fecundity of broodstock. Good correlations between the content of 20:4n-6 in eggs and the fecundity (r(2)=0.6109) and egg production (r(2)=0.9876) of broodstock were found. On the other hand, 22:6n-3 and DHA/EPA ratio was negatively correlated with the fecundity of broodstock (r(2)=0.5362, 0.8702 respectively). The result also showed that the balance between n-3 and n-6 fatty acid families, total polyunsaturated fatty acids and total saturated fatty acid and 20:5n-3 (EPA) and 22:6n-3 (DHA) may play vital roles in maturation and reproductive performance of P. monodon broodstock.