1996 Volume 62 Issue 4 Pages 610-619
The effect of broodstock diets on the chemical components of eggs produced by yellowtail was investigated to collect some basic data necessary for the development of a quality dry pellet for this species. The assessment was done by feedingyellowtail broodstock with either frozenraw fish (RF), moistn pellet (MP) or soft-dry pellet (SDP) for about 2 1/2 months prior to spawning. Themilt, buoyant eggs and larvae obtained from yellowtail broodstock of each testdiet group were analyzed for lipid classes, fatty acids, carotenoids, and vitamins A and E.
Eggs and milt obtained from yellowtail broodstock fed the various types of dietsshowed the typical pattern of fatty acids found in marine pelagic eggs and milt. Those derived from broodstock fed SDP contained the highest level of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). It was noted here again that the fatty acid profile and vitamin E content in eggs and milt were related to their availability in the broodstock diets. The carotenoid composition of the eggs was also greatly affected by the conversion or deposition of carotenoid from broodstock diets. In this study, egg quality was found to be high in brood fish which had been fed SDP containing 10% krill meal. They possessed a strong yellowish color with a high content of zeaxanthin and lutein. The eggs from the MP group werecomparatively lighter in color and those from the RF were still paler. Consequently, the quality of the yellowtail eggs seemed to be related to the carotenoid contained in them.
