title: A metabolic profile in Ruditapes philippinarum associated with growth-promoting effects of alginate hydrolysates.
abstract: The aim of this study is to demonstrate the growth-promoting effect of alginate hydrolysates (AHs) on the Manila clam Ruditapes philippinarum, and to verify the physiological change occurring within a living R. philippinarum stimulated by AHs. We show that growth of clams was dramatically promoted by supplementing a diet of the diatom Chaetoceros neogracile with AHs at 4 mg/L. Furthermore, metabolomics indicates that each state of starvation, food satiation, and sexual maturation have a characteristic pattern. In the groups given AHs in addition to C. neogracile in particular, excess carbohydrate was actively utilized for the development of reproductive tissue. In contrast, it appeared that clams in the groups given C. neogracile only were actively growing, utilizing their adequate carbohydrate resources. Meanwhile, the unfed groups have slowed growth because of the lack of an energy source. Hence, supplementation of AHs in addition to the algal diet may be an inexpensive way to shorten the rearing period of R. philippinarum. Moreover, metabolomics can evaluate the growth condition of R. philippinarum in a comprehensive way, and this approach is crucially important for not only the development of a mass culture method but also for the conservation of the clam resource in the field.
authors.affiliation: Laboratory of Environmental Biology, Department of Applied Aquabiology, National Fisheries University, Yamaguchi, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Yamasaki
authors.affiliation: Yamaguchi Prefectural Fisheries Research Center, Yamaguchi, Japan.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Taga
authors.affiliation: Yamaguchi Prefectural Fisheries Research Center, Yamaguchi, Japan.
authors.forename: Masanobu
authors.initials: M
authors.lastname: Kishioka
authors.affiliation: Graduate School of Informatics and Engineering, The University of Electro-Communications, Tokyo, Japan.
authors.forename: Shuichi
authors.initials: S
authors.lastname: Kawano
mesh_terms: D000464:Alginates / Q000494:pharmacology*; D060105:Animal Shells / Q000033:anatomy & histology / Q000187:drug effects; D000818:Animals; D049872:Bivalvia / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism*; D002952:Citric Acid Cycle / Q000187:drug effects; D005943:Gluconeogenesis / Q000187:drug effects; D020723:Glucuronic Acid / Q000494:pharmacology; D006019:Glycolysis / Q000187:drug effects; D006603:Hexuronic Acids / Q000494:pharmacology; D006868:Hydrolysis; D055442:Metabolome / Q000187:drug effects; D055432:Metabolomics; D025341:Principal Component Analysis
chemical_list: D000464:Alginates; D006603:Hexuronic Acids; D020723:Glucuronic Acid