Abstract: Juvenile sea cucumber Apostichopusjaponicus Selenka with initial body weight of(1.0±0.2)g were reared in a 70 L plastic tank at 15 individuals per tank and fed diets containing 30% of sea weeds including Sargassum sp.(M), sea lettuce Ulva sp.(S), Enteromorpha sp.(H)and Sargassumfusiforme produced in Vietnam(YC), Indonesia(FC), and the Philippines(NC)with triplication at water temperature of(22±1)℃ for 60d to evaluate effects of dietary sea weed levels on growth, immunity, digestion and nutritional composition of juvenile sea cucumber and thus to alleviate shortage of raw material supply of feed and to reduce food cost.The results showed that the juvenile sea cucumber in group M and group YC had the maximal and second maximal final body weight, significantly higher than that in group H(P<0.05).There was the maximal intestine-body wall ratio in sea cucumber in group YC, significantly higher than that in group S and group H(P<0.05).The juvenile sea cucumber had the maximal weight gain rate in group M(218.22%), followed by in group NC(195.16%), significantly higher than that in group H(112.47%)(P<0.05), with lower ratio of viscera to body wall(VBWR)in group S(11.94%)and in group H(11.29%).The juvenile sea cucumber in group YC had significantly higher crude fat content(9.59%)in the body wall than that in the other groups(P<0.05).There was more amino acid content including glutamic acid, glycine, aspartic acid and arginine in the body walls in the sea cucumber, with the minimal content of total amino acid in group FC(361.22 mg/g), and the maximal total amino acid content in group YC(383.08 mg/g), significant difference between the both groups(P<0.05), and without significant difference compared with other groups(P>0.05).The maximal flavor amino acids were observed in the sea cucumber in group YC(190.22 mg/g), the minimal flavor amino acids(178.64 mg/g)in group FC, and(178.95 mg/g)in group H significant difference(P<0.05).The findings indicate that Vietnamese eelgrass can replace partial Sargassum as the main component of the sea cucumber compound feed and that sea lettuce can be used as an auxiliary ingredient to help increase the protein content in the feed of juvenile sea cucumber.
2020, Vol. 35 
