Hawaii Institute of Marine Biology, University of Hawaii, Kaneohe, United States.
ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Australia.
Elife. 2021 Jan 26;10:e59162. doi: 10.7554/eLife.59162.
As climate-driven heat waves become more frequent and intense, there is increasing urgency to understand how thermally sensitive species are responding. Acute heating events lasting days to months may elicit acclimation responses to improve performance and survival. However, the coordination of acclimation responses remains largely unknown for most stenothermal species. We documented the chronology of 18 metabolic and cardiorespiratory changes that occur in the gills, blood, spleen, and muscles when tropical coral reef fishes are thermally stressed (+3.0°C above ambient). Using representative coral reef fishes ( and ) separated by >100 million years of evolution and with stark differences in major life-history characteristics (i.e. lifespan, habitat use, mobility, etc.), we show that exposure duration illicited coordinated responses in 13 tissue and organ systems over 5 weeks. The onset and duration of biomarker responses differed between species, with - an active, mobile species - initiating acclimation responses to unavoidable thermal stress within the first week of heat exposure; conversely, - a sessile, territorial species - exhibited comparatively reduced acclimation responses that were delayed through time. Seven biomarkers, including red muscle citrate synthase and lactate dehydrogenase activities, blood glucose and hemoglobin concentrations, spleen somatic index, and gill lamellar perimeter and width, proved critical in evaluating acclimation progression and completion, as these provided consistent evaluation of thermal responses across species.
随着气候驱动的热浪变得更加频繁和剧烈，越来越需要了解热敏感物种的反应。持续数天到数月的急性加热事件可能会引发适应反应，以提高性能和生存能力。然而，对于大多数狭温物种来说，适应反应的协调仍然知之甚少。我们记录了当热带珊瑚礁鱼类受到热胁迫（比环境温度高 3.0°C）时，鳃、血液、脾脏和肌肉中发生的 18 种代谢和心肺呼吸变化的时间顺序。使用代表珊瑚礁鱼类（ 和 ），它们在 1 亿多年的进化过程中分离，并且在主要生活史特征（即寿命、栖息地利用、流动性等）上存在明显差异，我们表明，暴露持续时间在 5 周内引起了 13 个组织和器官系统的协调反应。生物标志物反应的开始和持续时间因物种而异， - 一种活跃、移动的物种 - 在热暴露的第一周内就开始对不可避免的热应激产生适应反应；相反， - 一种固着、有领地的物种 - 表现出相对减少的适应反应，这些反应随着时间的推移而延迟。七种生物标志物，包括红肌柠檬酸合酶和乳酸脱氢酶活性、血糖和血红蛋白浓度、脾脏体指数以及鳃片层周长和宽度，对于评估适应进展和完成至关重要，因为这些标志物在物种间提供了对热反应的一致评估。
