Evaluation Of L-ascorbyl-2-glucose as the source of vitamin C for juvenile Korean rockfish Sebastes schlegeli (Hilgendorf)

This study was conducted to compare L-ascorbyl-2-glucose (AA2G) with L-ascorbyl-2-monophosphateNa/Ca (AMP-Na/Ca) for supplying the dietary vitamin C for juvenile Korean rockfish Sebastes schlegeli (Hilgendoro. Fish were fed one of seven semi-purified diets containing equivalents of 0, 50, 100 and 200 mg ascorbic acid (AA) kg(-1) diet in the form of AA2 G or AMP-Na/Ca for 12 weeks. After 12 weeks of feeding, weight gain, feed efficiency ratio and survival of fish fed the vitamin C-free diet were significantly lower than those of fish fed the vitamin C-supplemented diets in either form. The hepatosomatic index, condition factor and survival of fish fed AMP-Na/Ca-100, AMP-Na/Ca-200, AA2G(100) and AA2G(200) diets were significantly higher than fish fed the vitamin C-free diet. After 9 weeks of feeding, fish fed the vitamin C-free diet began to show vitamin C deficiency signs such as anorexia and lethargy. At the end of the 12-week feeding trial, fish fed the vitamin C-free diet exhibited vitamin C deficiency signs, e.g., anorexia, scoliosis, exophthalmia and fin haemorrhage. Vitamin C retention in the muscle and liver was similar to those of fish fed AA2G- orAMP-Na/Ca-supplemented diets. In general, there was no significant difference in the muscle and liver vitamin C concentration in fish fed the AA2G and AMP-Na/Ca diets at the same supplementation levels.