油脂酵母で培養したティグリオプスのマコガレイ仔稚魚に対する餌料価値

抄録

A copepod, Tigriopus japonicus, is one of the few food organisms for which the mass culture technique has been well established, besides rotifer Brahionus plicatilis. But, the dietary value of T. japonicus varies among fishes, especially in Heterosomata (Pleuronectiformes).
The larvae of mud dab Limanda yokohamae (30 days old, 10.30± 0.51mm in T. L.) were fed T. japonicus cultured respectively with ω-Yeast containing high amounts of ω3 highly unsaturated fatty acids (ω3HUFA) and baker's yeast for 23 days to evaluate their dietary values. The survival rate and the growth of the fish fed T. japanicus cultured with ω-Yeast were better than those fed T. japonicus cultured with baker's yeast (97.4-97.0% in survival rate and 14.3-14.0 vs. 12.5-12.0 time increase in body weight), although both the groups showed excellent survival rate and growth. The differences in survival rate and growth between the treatments might be due to slightly higher contents of the lipid and ω3HUFA in the former. These results may indicate that T. japonicus, without regard to culture media, is a suitable food organism for mud dab of Pleuronectiformes, and that its nutritional quality is successfully improved by cultureing it with ω-Yeast. There seemed to be no correlation between abnormal coloration of the skin or reversal of the body sides and the ω3HUFA content in food, at least after the stage of 10mm in length.