Effects of dietary β-carotene and astaxanthin levels on anti-oxidation in juvenile sea cucumber Apostichopus japonicus

Sea cucumber Apostichopus japonicus with initial body weight of 3.89 g were stocked into 60 liter plastic tanks and fed the diets supplemented with β-carotene(groups A,B,and C) or astaxanthin(groups D,E,and F) at a dose of 30 mg/kg,60 mg/kg,and 90 mg/kg(without supplementation as control group,F) with triplication at water temperature of 11.0-20.0 ℃,a salinity of 35,and pH 7.5 for 80 days.The growth of the sea cucumber was monitored in a 20 day interval by specific growth rate(SGR),and total antioxidant capability(T-AOC),and activities of superoxide dismutase(SOD),and catalase(CAT) were determined at the end of the experiment to evaluate the effects of the additional β-carotene and astaxanthin on the antioxidation in the sea cucumber.There was increase in SGR in the sea cucumber fed the diets supplemented with β-carotene with the enhanced supplemental levels,6.67% higher in the 30 mg/kg group,73.33% higher in the 60 mg/kg group,and 100.0% higher in the 90 mg/kg group than that in the control group,and significantly different in group C from that in the control group(P0.05).The sea cucumber fed the diets supplemented with astaxanthin at a dose of 60 mg/kg and 90 mg/kg had 113.33% and 66.67% higher SGR than the sea cucumber fed the control diet did,the animals in group E having significantly higher SGR than the animals in the control group(P0.05).There was significant increase in T-AOC in the coelomic fluid in the sea cucumber fed the diets supplemented with β-carotene and astaxanthin with the enhanced supplemental levels(P0.05)except for in groups A and B.The sea cucumber fed the diets supplemented with astaxanthin(12.77 U/mL) had 45.61% higher coelomic fluid T-AOC than the sea cucumber fed the diets supplemented with β-carotene(8.77 U/mL) did,astaxanthin leading to higher antioxidation.In the activities of SOD,and CAT,however,there were significantly lower in the sea cucumber fed the diets supplemented with β-carotene and astaxanthin than those in the control(P0.05),without significant differences among groups A,B,D,and G.No significant differences were found in the body composition and the activities of proteinase and amylase in the treatment groups and control group(P0.05).