Supplemental Effect of Astaxanthin in Broodstock Diets on the Quality of Yellowtail Eggs

Abstract

Different levels of pure astaxanthin (0, 20, 30, and 40 ppm) were supplemented in soft-dry pellets (SDP), in order to clarify the effect of this carotenoid on the quality of eggs and spawning performance of yellowtail. Three-year-old fish of average body weight 6.1 kg were separately fed one of each test diet. The feeding experiment was carried out in cages for about 5 months prior to spawning. Seven males and 7 females from each test diet group were transferred to 65 m3 indoor spawning tanks to per mit them to spawn spontaneously, while those which remained in the cages were artificially inseminat ed. Fish of both spawning investigations were induced to maturity by HCG injection (600 IU/kg-fish).