Physiological regulation of heat exchange during thermoregulation in fishes

Research Project

Project/Area Number	18K14513
Research Category	Grant-in-Aid for Early-Career Scientists
Allocation Type	Multi-year Fund
Review Section	Basic Section 40030:Aquatic bioproduction science-related
Research Institution	Nagasaki University
Principal Investigator	NAKAMURA Itsumi 長崎大学, 海洋未来イノベーション機構, 助教 (60774601)
Project Period (FY)	2018-04-01 – 2021-03-31
Project Status	Completed (Fiscal Year 2020)
Budget Amount *help	¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000) Fiscal Year 2020: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000) Fiscal Year 2019: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000) Fiscal Year 2018: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
Keywords	外温性魚類 / 体温調節 / 心拍数 / 体温 / 熱交換 / データロガー / バイオロギング
Outline of Final Research Achievements	Ectothermic fishes use environmental temperature to regulate their body temperature, and it has been suggested that physiological regulation of heat exchange rate. Experiments in which live fish were exposed to temperature change, and body temperature changes and heart rate of the fish were measured. The heat-budget models were used to estimate the variation of the whole-body heat-transfer coefficients, which tended to be higher during warming than during cooling, and the heat-transfer coefficients were positively correlated with heart rate, suggesting that heart rate affects the heat-transfer coefficient.
Academic Significance and Societal Importance of the Research Achievements	魚類が行動的体温調節を行う際に外界との熱交換率が変化することは知られていたが、そのメカニズムは明らかになっていなかった。本研究によって、体温変化に際して心拍数が変化し、それによって熱交換率が変化することが示唆された。近年、地球温暖化に伴う海水温上昇が報告されており、水温環境を利用して体温調節を行う外温性魚類の行動や分布への影響が懸念されている。外温性魚類が環境を利用した体温調節をする際の生理的な調節メカニズムや能力を明らかにすることで、海洋の環境変動に対して魚類がどのように行動的に応答するかを予測するのに役立つと考えられる。