Nutritional studies in the seed production of fish-XX. Effective components in cuttlefish meal and raw krill for improvement of quality of red seabream Pagrus major eggs.

Abstract

Red seabream broodstock were fed various diets of different nutritionalquality for either 26 days or shortly before spawning to clarify theeffective components in cuttlefish meal and raw krill which aid inquality egg production.The percentage of buoyant eggs was lowest in the control group receivingthe white fish meal diet, and was elevated by the addition of 200 mgDL-alpha-tocopheryl acetate. The value was also effectively improved byreplacement of white fish meal with defatted or intact cuttlefish mealas a protein source. Feeding broodstock with frozen raw krill afterpreviously being fed control diet resulted in elevation of thepercentage of buoyant eggs and normal larvae. Equally good results wereobtained by substitution of cuttlefish liver oil in the control dietwith 2.5% krill polar lipid or 2.5% krill nonpolar lipid. However,neither defatted krill meal nor fat-soluble fraction of cuttlefish mealshowed the good effect on the egg quality.Consequently, the superior quality of cuttlefish meal to the white fishmeal as a protein source for red seabream broodstock diets wasreconfirmed. And the effective components in raw krill, aiding thereproduction of red seabream, are suggested to be the polar and nonpolarlipid fractions. In addition, vitamin E was also found to have the sameefficiency for improvement of the egg quality.