Effect of Nutritional Quality of Diets Given to Broodstock on the Verge of Spawning on Reproduction of Red Sea Bream

Abstract

This study was conducted to examine the effect of nutritional quality of diets given to broodstock on the verge of spawning on reproduction of red sea bream, and to clarify whether or not egg quality is improved by enhancing incorpration of pigments from diets. The percentage of buoyant eggs was found to be improved by supplementing pigments such as β-carotene and canthaxanthin or astaxanthin to the diets given to broodstock on the eve of spawning. Feeding frozen raw krill shortly before spawning also resulted in marked improvement in both the total eggs produced and the percentage of buoyant eggs. On the other hand, in the group fed on the corn oil diet on the verge of spawning the proportion of buoyant eggs was markedly reduced from the original value by replacement of cuttlefish liver oil with corn oil. The rate of hatching was not improved by addition of pigments, but abnormality in number and position of oil globules was reduced and consequently the total number of normal larvae obtained became higher than in the original broodstock. These values were also effectively improved by feeding on frozen raw krill and the percentage of normal larvae obtained from buoyant eggs was elevated from the original value of 51.6% to 91.2%, whereas replacement of cuttlefish liver oil with corn oil in the diet given to broodstock even in a short period during spawning resulted in lowering of these values. © 1984, The Japanese Society of Fisheries Science. All rights reserved.