Breath holding as a thermoregulation strategy in the deep-diving scalloped hammerhead shark

• 成果类型: Article
• 署名作者: Royer, Mark; Meyer, Carl; Royer, John; Maloney, Kelsey; Cardona, Edward; Blandino, Chloe; da Silva, Guilherme Fernandes; Whittingham, Kate; Holland, Kim N.
• 署名单位: University of Hawaii System; University of Edinburgh; Universidade Federal de Sao Paulo (UNIFESP); University of Hawaii System; Whitman College
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-8440
• DOI: 10.1126/science.add4445
• 发表日期: 2023-05-11
• 页码: 651-655
• 关键词: sphyrna-lewini; heat-transfer; behavioral thermoregulation; movement patterns; bigeye tuna; fish; endothermy; temperatures; performance; excursions

摘要

Fish moving between different thermal environments experience heat exchange via conduction through the body wall and convection from blood flow across the gills. We report a strategy of preventing convective heat loss at the gills during excursions into deep, cold water by the tropical scalloped hammerhead shark (Sphryna lewini). Adult scalloped hammerhead sharks dive rapidly and repeatedly from warm (similar to 26 degrees C) surface waters to depths exceeding 800 meters with temperatures as low as 5 degrees C. Biologgers attached to adult sharks show that warm muscle temperatures were maintained throughout the deepest portion of each dive. Substantive cooling only occurred during the latter stages of the ascent phase and, once initiated, was rapid. Heat transfer coefficient modeling indicated that convective heat transfer was suspended, probably by suppressing gill function during deep dives. This previously unobserved strategy has broad similarities to marine mammal breath hold diving.