2018 Fiscal Year Final Research Report

Development of a novel method to invasively evaluate the health condition of the fish using fish stool multifaceted analysis

Research Project

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Project/Area Number	16K14964
Research Category	Grant-in-Aid for Challenging Exploratory Research
Allocation Type	Multi-year Fund
Research Field	Aquatic bioproduction science
Research Institution	Fisheries Research and Education Agency
Principal Investigator	Hano Takeshi 国立研究開発法人水産研究・教育機構, 瀬戸内海区水産研究所, 主任研究員 (30621057)
Co-Investigator(Kenkyū-buntansha)	伊藤克敏国立研究開発法人水産研究・教育機構, 瀬戸内海区水産研究所, 主任研究員 (80450782) 伊藤真奈国立研究開発法人水産研究・教育機構, 瀬戸内海区水産研究所, 研究員 (60735900) 内田基晴国立研究開発法人水産研究・教育機構, 瀬戸内海区水産研究所, 主幹研究員 (70371961)
Project Period (FY)	2016-04-01 – 2019-03-31
Keywords	糞便 / 環境ストレス / 代謝物 / 腸内細菌 / 非侵襲的評価
Outline of Final Research Achievements	This study aimed to develop a novel method to invasively evaluate the health condition of the fish using fish stool analysis. Marine teleost aquaculture fish, Pagrus major, were reared under two distinct environmental stresses: harmful chemical exposure and high stock density. Feces collected from the fish were examined the alterations of their metabolite content, carbon source utilization by microbiota, and microbial community. First, fish were exposed to phenanthrene, one of toxic polycyclic hydrocarbons, for 2 weeks. As a result, fecal parameters, in accordance with the increased levels of stress markers, dramatically changed. Next, fish were reared under varying densities for 3 weeks: low (5 g/L) and high (15 g/L). We observed growth inhibition as well as alteration of fecal endpoints in the high stock density treatment. This study provides further insight into the effective use of fecal samples to potentially determine farmed fish health.
Free Research Field	水産生物環境学
Academic Significance and Societal Importance of the Research Achievements	本研究は、従来は不要な排泄物として処分されてきた魚類糞便に着目し、その変化から健康状態を診断する手法の開発を目指して行った。海産魚（マダイ）に実環境中で想定される環境ストレス（化学物質、密殖）に曝し、糞便中の代謝物組成、腸内細菌叢を調査した結果、これらの指標が変化することを見出した。すなわち、魚の健康の異常を、糞便により非侵襲的に検出できる可能性が示唆された。将来的には、養殖現場での適用、例えば、養殖マグロなど慎重な取り扱いが求められる商品の健康診断への適用や、生簀内の糞便から生簀内の環境の健全度を診断する技術への適用が期待される。