Scholarlink

<p>Herbivorous fishes play a vital role in maintaining coral reef health and dominance by mitigating algal overgrowth. However, the functional traits of these fishes are increasingly threatened by marine heatwaves and rising ocean temperatures that cause coral bleaching, as these encroach on the thermal tolerance limits of sensitive species and drive some to vacate thermally stressed habitats. Using a controlled laboratory setup, we assessed the critical thermal maximum (CT<sub>max</sub>), temperature preference (<i>T</i><sub>pref</sub>), and avoidance temperature (<i>T</i><sub>avoid</sub>) of a common herbivorous coral reef fish <i>Acanthurus triostegus</i> (manini) under seasonal (winter = 24.0 ± 0.1&#xa0;°C, summer = 27.5 ± 0.1&#xa0;°C) and marine heatwave conditions (31.0 ± 0.1&#xa0;°C). CT<sub>max</sub> increased significantly under marine heatwave conditions (from ~ 37.2&#xa0;°C in winter to 39.0&#xa0;°C at the peak of a marine heatwave), demonstrating an unexpected flexibility in thermal tolerance and an encouraging degree of thermal buffer before ecological death ensues. However, <i>T</i><sub>pref</sub> and <i>T</i><sub>avoid</sub> remained consistent across all treatments (preferring ~ 29.3–30.2&#xa0;°C and avoiding ~ 31.8–32.3&#xa0;°C), highlighting a narrow thermal window for ecological functions. Consequently, while <i>A. triostegus</i> can physiologically withstand acute heating, their strong preference for cooler conditions and avoidance of MHW conditions suggest that behavioral responses, rather than physiological limits, may constrain their capacity to maintain abundance and while many deliver top-down algal control on warming reefs.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Herbivores in hot water: thermal limits and avoidance of marine heatwave conditions by Acanthurus triostegus

  • 期刊论文

  • 发表日期：

    2026年3月20日

查看全文
  • Taylor Souza,
  • Michelle María Early Capistran,
  • Larry Crowder,
  • Jacob L. Johansen

摘要

Herbivorous fishes play a vital role in maintaining coral reef health and dominance by mitigating algal overgrowth. However, the functional traits of these fishes are increasingly threatened by marine heatwaves and rising ocean temperatures that cause coral bleaching, as these encroach on the thermal tolerance limits of sensitive species and drive some to vacate thermally stressed habitats. Using a controlled laboratory setup, we assessed the critical thermal maximum (CTmax), temperature preference (Tpref), and avoidance temperature (Tavoid) of a common herbivorous coral reef fish Acanthurus triostegus (manini) under seasonal (winter = 24.0 ± 0.1 °C, summer = 27.5 ± 0.1 °C) and marine heatwave conditions (31.0 ± 0.1 °C). CTmax increased significantly under marine heatwave conditions (from ~ 37.2 °C in winter to 39.0 °C at the peak of a marine heatwave), demonstrating an unexpected flexibility in thermal tolerance and an encouraging degree of thermal buffer before ecological death ensues. However, Tpref and Tavoid remained consistent across all treatments (preferring ~ 29.3–30.2 °C and avoiding ~ 31.8–32.3 °C), highlighting a narrow thermal window for ecological functions. Consequently, while A. triostegus can physiologically withstand acute heating, their strong preference for cooler conditions and avoidance of MHW conditions suggest that behavioral responses, rather than physiological limits, may constrain their capacity to maintain abundance and while many deliver top-down algal control on warming reefs.