Developing a new method for understanding temperature adaptation of large pelagic fishes

2021 Fiscal Year Final Research Report

• Project/Area Number: 16H04973
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Aquatic bioproduction science
• Research Institution: National Institute of Polar Research
• Principal Investigator: Watanabe Yuuki 国立極地研究所, 研究教育系, 准教授 (60531043)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: 行動生態 / 環境適応 / 魚類 / 体温

Outline of Final Research Achievements

Using biologging technology, we gained new insights into how the behavior and physiology of large pelagic fishes are affected by the ambient water temperature and their body temperature. White sharks exhibited both an advantage (i.e., elevated locomotor performance) and disadvantage (i.e., elevated energy expenditure) associated with their endothermic physiology. Blue sharks, an ectothermic species, had high thermal inertia due to their large body mass and maintained their body temperature within a narrow range during diving, where the ambient water temperature changed widely. We also found that, in many large pelagic fishes, the rate of change in body temperature is faster during the warming process than cooling process. This finding suggests that their body temperature is not solely determined by the ambient water temperature but is controlled physiologically to some extent.

Free Research Field

海洋生物学

Academic Significance and Societal Importance of the Research Achievements

水温を変化させる飼育実験が不可能な外洋性大型魚類において、バイオロギングの手法を応用することで、行動や生理と水温および体温との関わりを詳しく調べられることを実証した。ホホジロザメの研究では、内温性という珍しい特徴を持つ本種の行動を計測し、内温性のメリットとデメリットを定量的に示した。この成果は、一部の魚類で進化した内温性の進化的意義の解明に繋がると考えられる。また、ヨシキリザメの研究では、連続した潜水が体温調節の機能を持つことを示した。水温の鉛直プロファイルから滞在深度の範囲を正確に予測できることが示唆され、本種の資源管理の精度向上に繋がることが期待される。