Effects of Sources and Levels of Dietary Carbohydrate on Growth and Body Composition of Juvenile Sea Cucumbers, Apostichopus japonicus

A factorial feeding trial of different levels of three carbohydrate sources (wheat flour, $\alpha$-potato starch, and sodium alginate) was conducted to determine proper sources and levels of dietary carbohydrate for juvenile sea cucumbers. Three replicate groups of juvenile sea cucumbers (770 mg average weight) were fed the experimental diets once a day for 10 weeks. After feeding trial, survival of sea cucumbers was not significantly different between diets. The body weight of sea cucumbers was significantly (P<0.01) affected by both source and level of dietary carbohydrate, tending to decrease as dietary carbohydrate level increased. Body weight of sea cucumbers fed a 25% wheat flour diet was the highest but was not significantly different from that of sea cucumbers fed diet containing 10% wheat flour with 15% sodium alginate (P>0.05). No significant differences were observed in contents of moisture, crude protein, crude lipid and ash of sea cucumbers among dietary treatments. These results suggest that sea cucumbers utilize wheat flour and sodium alginate more efficiently than they do $\alpha$-potato starch, and that a formulated diet containing 43-60% carbohydrate may be suitable for juvenile sea cucumber culture.