Effects of dietary Chlorella ellipsoidea supplementation on growth, blood characteristics, and whole-body composition in juvenile Japanese flounder Paralichthys olivaceus

The study was conducted to investigate the effects of dietary Chlorella powder (C) supplementation on growth performance, blood characteristics, and whole-body composition in juvenile Japanese flounder Paralichthys olivaceus. Four experimental diets were supplemented with C at 0, 1, 2 and 4% (C-0, C-1, C-2, and C-4) on a dry-weight basis. Three replicate groups of fish averaging 1.13 +/- 0.02 g (Mean +/- SD) were randomly distributed in each aquarium and fed one of four experimental diets for 12 wk. After 12 wk of the feeding trial, fish fed C-2 diet had higher weight gain (WG), feed efficiency (FE), and protein efficiency ratio (PER) than did fish fed C-0 and C(1)diets (P < 0.05); however, there was no significant difference among fish fed C-1 and C-4 diets, and among fish fed C-2 and C-4 diets (P > 0.05). Fish fed C-2 and C-4 diets had a lower serum cholesterol level than did fish fed C-0 and C-1 diets (P < 0.05). Fish fed C-2 and C-4 diets had a lower body fat than did fish fed C-0 (P < 0.05). These results indicate that dietary supplementation of 2% Chlorella powder in the commercial diets could improve growth, feed utilization, serum cholesterol level, and whole-body fat contents in juvenile Japanese flounder.