Feeding trial of Chlorella-extract was carried out on cultured ayu, Plecoglossus altivelis, in order to confirm the effect on improvement of physiological condition. The rearing with the extract supplemented diet during 50 days endowed some physiological effects as follows.

Despite no effect on weight gain, the supplement of the extract slightly reformed the fattened ayu to natural shape in addition to improvement of sensory evaluation in taste. In regard to body composition, the extract significantly depressed the body lipid level and changed the lipid class composition of the lipid reserve. Furthermore, in order to compare the mobilization pattern of body constituents to energy, the fish were kept during 21 days without feeding. The extract supplemented ayu was lower in loss of body weight under the starvation, because the reserved lipid was effectively mobilized to energy and protein was retained. Therefore it might be concluded that the Chlorella-extract activated lipid metabolism as lipid accumulation and lipid mobilization.