PDF(Pubmed)
Abstract：
The impact of ocean warming on fish and fisheries is vigorously debated. Leading theories project limited adaptive capacity of tropical fishes and 14-39% size reductions by 2050 due to mass-scaling limitations of oxygen supply in larger individuals. Using the world\'s hottest coral reefs in the Persian/Arabian Gulf as a natural laboratory for ocean warming - where species have survived >35.0 °C summer temperatures for over 6000 years and are 14-40% smaller at maximum size compared to cooler locations - we identified two adaptive pathways that enhance survival at elevated temperatures across 10 metabolic and swimming performance metrics. Comparing Lutjanus ehrenbergii and Scolopsis ghanam from reefs both inside and outside the Persian/Arabian Gulf across temperatures of 27.0 °C, 31.5 °C and 35.5 °C, we reveal that these species show a lower-than-expected rise in basal metabolic demands and a right-shifted thermal window, which aids in maintaining oxygen supply and aerobic performance to 35.5 °C. Importantly, our findings challenge traditional oxygen-limitation theories, suggesting a mismatch in energy acquisition and demand as the primary driver of size reductions. Our data support a modified resource-acquisition theory to explain how ocean warming leads to species-specific size reductions and why smaller individuals are evolutionarily favored under elevated temperatures.
摘要：
海洋变暖对鱼类和渔业的影响正在激烈辩论。领先的理论预测，热带鱼的适应能力有限，到2050年，由于较大个体的氧气供应受到大规模限制，尺寸减少了14-39％。使用波斯/阿拉伯湾世界上最热的珊瑚礁作为海洋变暖的自然实验室-物种在夏季温度>35.0°C的情况下存活了6000多年，并且在最大尺寸上比凉爽的地方小14-40％-我们确定了两种适应性途径，可以在10种代谢和游泳性能指标中提高高温下的存活率。比较来自波斯/阿拉伯湾内外珊瑚礁的Lutjanusehrenbergii和Scolopsisghanam，温度为27.0°C，31.5°C和35.5°C，我们发现，这些物种显示出低于预期的基础代谢需求和右移的热窗口的上升，这有助于将氧气供应和有氧性能保持在35.5°C。重要的是,我们的发现挑战了传统的氧限制理论,这表明能源获取和需求的不匹配是规模缩减的主要驱动因素。我们的数据支持修改后的资源获取理论，以解释海洋变暖如何导致特定物种的大小减少，以及为什么较小的个体在高温下在进化上受到青睐。
