Allen-Waller Luella, Glass Benjamin H, Jones Katelyn G, Dworetzky Anna, Barott Katie L
Department of Ecology & Evolution, The University of Chicago, Chicago, IL, USA.
Department of Biology, The University of Pennsylvania, Philadelphia, PA, USA.
bioRxiv. 2025 Aug 23:2025.08.19.670901. doi: 10.1101/2025.08.19.670901.
Heat stress can disrupt acid-base homeostasis in reef-building corals and other tropical cnidarians, often leading to cellular acidosis that can undermine organismal function. Temperate cnidarians experience a high degree of seasonal temperature variability, leading us to hypothesize that temperate taxa have more thermally robust pH homeostasis than their tropical relatives. To test this, we investigated how elevated temperature affects intracellular pH and calcification in the temperate coral . Clonal pairs were exposed to elevated (30°C) or control (22°C) temperatures for 17 days. Despite causing damage to host tissues and symbiont cells, elevated temperature did not affect intracellular pH or inhibit calcification in . These responses contrast with those of tropical cnidarians, which experience cellular acidification and decreased growth during heat stress. therefore appears to have thermally resilient cellular acid-base homeostasis mechanisms, possibly due to adaptation to large seasonal temperature variations. However, we also observed tissue damage and lower egg densities in heat-treated individuals, suggesting that increasingly severe marine heatwaves can still threaten temperate coral fitness. These results provide insight into corals' nuanced adaptive capacity across latitudes and biological scales.
热应激会破坏造礁珊瑚和其他热带刺胞动物的酸碱平衡，常常导致细胞酸中毒，进而损害机体功能。温带刺胞动物经历高度的季节性温度变化，这使我们推测温带类群比其热带近亲具有更强健的热pH平衡能力。为了验证这一点，我们研究了温度升高如何影响温带珊瑚的细胞内pH值和钙化作用。将克隆对暴露于升高的温度（30°C）或对照温度（22°C）下17天。尽管高温对宿主组织和共生体细胞造成了损害，但并未影响细胞内pH值，也未抑制其钙化作用。这些反应与热带刺胞动物不同，热带刺胞动物在热应激期间会经历细胞酸化和生长减缓。因此，似乎具有热弹性的细胞酸碱平衡机制，这可能是由于对季节性温度大幅变化的适应。然而，我们还观察到热处理个体存在组织损伤和较低的卵密度，这表明日益严重的海洋热浪仍可能威胁温带珊瑚的健康。这些结果为珊瑚在纬度和生物尺度上细微的适应能力提供了见解。
