title: Effects of dietary nucleotides on growth, non-specific immune response and disease resistance of sea cucumber Apostichopus japonicas.
abstract: A 9-week feeding trial was conducted to investigate the effects of dietary nucleotides (NT) on growth, immune response and disease resistance of sea cucumber Apostichopus japonicas (initial weight: 5.87 ± 0.03 g). Four graded levels of dietary NT were designed as 0, 150, 375 and 700 mg/kg, respectively. After the feeding trial, sea cucumbers were challenged with Vibrio splendidus for the determination of disease resistance. The results showed that the specific growth rates were significantly higher in sea cucumber fed the diet with 375 mg/kg NT than those fed the basal diet without NT supplementation (P < 0.05). The highest total coelomocytes counts in coelomic ﬂuid were found in the treatment with 150 mg/kg of dietary NT (P < 0.05). Compared to those fed with the basal diet, sea cucumber fed diets with nucleotides (≥ 375 mg/kg) had significantly higher phagocytic activities in coelomic ﬂuid (P < 0.05). Respiratory burst activities in coelomic ﬂuid significantly increased with increasing dietary NT supplementations up to 700 mg/kg (P < 0.05). No significant differences in the activities of superoxide dismutase, total nitric oxide synthase and acid phosphatase in coelomic ﬂuid were found among all the treatments (P > 0.05). After being challenged with V. splendidus, the cumulative mortalities of sea cucumber fed diets with 150 and 375 mg/kg NT were significantly lower than that in the treatment without dietary nucleotide supplementation (P < 0.05). Under the experimental conditions, the present results conﬁrmed that a diet supplemented with 375 mg/kg NT is able to enhance both non-speciﬁc immune response and growth of sea cucumber in vivo. In conclusion, it was showed that dietary NT does increase the growth performance, non-specific immunity and disease resistance of sea cucumber. The optimum dietary NT supplementation level for sea cucumber was found to be 375 mg/kg. The application of dietary NT may present a novel strategy for health management in sea cucumber's aquaculture.
authors: The Key Laboratory of Aquaculture Nutrition and Feeds, Ministry of Agriculture, The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China.
authors: Zehong
authors: Z
authors: Wei
authors: The Key Laboratory of Aquaculture Nutrition and Feeds, Ministry of Agriculture, The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China.
authors: Lina
authors: L
authors: Yi
authors: The Key Laboratory of Aquaculture Nutrition and Feeds, Ministry of Agriculture, The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China.
authors: Wei
authors: W
authors: Xu
authors: The Key Laboratory of Aquaculture Nutrition and Feeds, Ministry of Agriculture, The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China.
authors: Huihui
authors: H
authors: Zhou
authors: The Key Laboratory of Aquaculture Nutrition and Feeds, Ministry of Agriculture, The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China.
authors: Yanjiao
authors: Y
authors: Zhang
authors: The Key Laboratory of Aquaculture Nutrition and Feeds, Ministry of Agriculture, The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China. Electronic address: wzhang@ouc.edu.cn.
authors: Wenbing
authors: W
authors: Zhang
authors: The Key Laboratory of Aquaculture Nutrition and Feeds, Ministry of Agriculture, The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China.
authors: Kangsen
authors: K
authors: Mai
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000818:Animals; D017756:Aquaculture; D004032:Diet; D019587:Dietary Supplements / Q000032:analysis; D007113:Immunity, Innate; D009711:Nucleotides; D012616:Sea Cucumbers / Q000254:growth & development* / Q000276:immunology*; D014733:Vibrio / Q000502:physiology
chemical_list: D009711:Nucleotides
keywords: Apostichopus japonicas; Disease resistance; Growth; Immunity; Nucleotide