Comparative studies on seasonal reproduction of fish in tropical monsoon environments

2018 Fiscal Year Final Research Report

• Project/Area Number: 16H05796
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 海外学術
• Research Field: Aquatic life science
• Research Institution: University of the Ryukyus
• Principal Investigator: TAKEMURA Akihiro 琉球大学, 理学部, 教授 (40222103)
• Co-Investigator(Kenkyū-buntansha): 竹内 悠記 早稲田大学, 理工学術院, 助教 (00754904)
• Research Collaborator: NGUYEN Ngoc Phuoc
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: ベトナム / ゴマアイゴ / 日長 / 水温 / 栄養

Outline of Final Research Achievements

The aim of this study was to evaluate involvement of periodical changes in environmental factors in tropical waters in reproductive activity of reef fishes. When the goldlined spinefoot Siganus guttatus were collected monthly in the lagoon, Hue city, Vietnam, the gonadal activity of this species increased from April to May, suggesting that increases in water temperature and photoperiod are related to initiation of gonadal development in this species. Realtime quantitative PCR revealed that the transcript levels of leptin in the brain and liver increased when fish were reared under food-limited conditions, suggesting that food availability becomes a driver of gonadal development of this species, It is concluded that the goldlined spinefoot inhabiting in Vietnam shares characteristics of environmental perception between tropical and subtropical waters.

Free Research Field

魚類生理学

Academic Significance and Societal Importance of the Research Achievements

熱帯モンスーン気候帯は雨季と乾季の季節変化を示すが、赤道から南北へ離れるに従って、日長や温度の周年変化が現れるようになる。これまで、インドネシア（中部ジャワ）や沖縄で同じ手法を用いて行ってきた結果と比較した場合、ベトナム中部に生息するゴマアイゴは、熱帯と亜熱帯の環境変動を巧みに利用した繁殖戦略を持っていることが明らかとなった。これらの結果は、当該地域の水産業の振興に利用できる考えられる。