Tiny Hairs That Help Corals Breathe May Malfunction in Warming Oceans
Tiny Hairs That Help Corals Breathe May Malfunction in Warming Oceans
帮助珊瑚呼吸的微小纤毛，在变暖的海洋中可能会“罢工”
At first glance, corals present as little more than colorful rocks—piles of lobes, stalagmites, and branches poking out from the seafloor. They are anything but. Corals are complex creatures that form enduring colonies, and just like other animals they need oxygen to live. Across the living surface of coral, a frantic dance of survival takes place, invisible to our eyes and unknown to science before 2014. The tiny dancers are hairlike cilia, and new research into these microscopic structures is revealing just how active corals are in determining their own fate.
乍看之下，珊瑚似乎不过是些色彩斑斓的岩石——从海底探出的叶状体、石笋和枝杈。但事实远非如此。珊瑚是复杂的生物，它们形成持久的群落，并且像其他动物一样，需要氧气才能生存。在珊瑚的活体表面，一场疯狂的生存之舞正在上演，这在 2014 年之前对人类肉眼不可见，对科学界也尚属未知。这些微小的舞者是毛发状的纤毛，而针对这些微观结构的新研究正在揭示，珊瑚在决定自身命运方面是多么积极主动。
Corals aren’t fortunate enough to have a consistent supply of oxygen, and they can’t change location to seek it out. During the day, the tiny polyps that make up a coral colony get plenty of oxygen from the symbiotic algae that photosynthesize within their tissues. But at night that process stops, and a coral polyp’s only source of oxygen is the water around it. Then it’s do or die for the cilia. Using mechanisms scientists are still trying to understand, the cilia wave around to generate fast-moving vortices of water that circulate oxygen to the coral’s outer tissues, in addition to helping keep the colonies free of sediment.
珊瑚没有那么幸运，无法获得持续的氧气供应，也无法通过移动位置来寻找氧气。白天，构成珊瑚群落的微小水螅体可以从组织内进行光合作用的共生藻类那里获得充足的氧气。但到了晚上，这一过程停止了，珊瑚水螅体唯一的氧气来源就是周围的水。这时，纤毛就成了决定生死的关键。纤毛利用科学家们仍在研究的机制摆动，产生快速移动的水涡流，将氧气输送到珊瑚的外层组织，同时还有助于保持群落表面没有沉积物。
A study published in Science in May 2026 provides new insight into how organisms with no brain or musculoskeletal system can generate and regulate this process—and what happens when the water around them warms up. Warmer water naturally carries less oxygen, which prompts corals to move their cilia faster and faster, as if gasping for breath. Above a certain temperature, the system starts to work against itself; the furious beating of cilia uses up any oxygen the coral’s tissues can absorb, and then the polyps can suffocate in the less oxygenated water. Biophysicists, marine biologists, mathematicians, and modelers are now collaborating to better understand the physiological and hydrodynamic forces at work, and how they correlate with bleaching patterns, coral disease, and mass die-offs.
2026 年 5 月发表在《科学》杂志上的一项研究提供了新的见解，揭示了没有大脑或肌肉骨骼系统的生物如何产生和调节这一过程，以及当周围水温升高时会发生什么。较暖的水自然携带较少的氧气，这促使珊瑚越来越快地摆动纤毛，仿佛在喘息。当温度超过一定限度时，这个系统就开始适得其反；纤毛的剧烈摆动消耗了珊瑚组织所能吸收的所有氧气，随后水螅体可能会在缺氧的水中窒息。生物物理学家、海洋生物学家、数学家和建模专家目前正在合作，以更好地理解其中的生理和流体动力学作用力，以及它们如何与白化模式、珊瑚疾病和大规模死亡相关联。
This dynamic picture is somewhat new to scientists, who have long used corals’ symbiotic algal partners as indicators of their health. Cilia may serve as a more direct signal, said Rachel Alderdice, a marine biologist who studies coral stress biomarkers and genomics at the University of Konstanz in Germany and was not involved in the research. “It’s these finer details that could help us understand why some corals bleach and others don’t, [even when] they sit right beside each other.”
这种动态图景对科学家来说是相对较新的，他们长期以来一直将珊瑚的共生藻类伙伴作为其健康状况的指标。德国康斯坦茨大学研究珊瑚压力生物标志物和基因组学的海洋生物学家雷切尔·奥尔德代斯（Rachel Alderdice）表示，纤毛可能是一个更直接的信号。她并未参与这项研究，但她认为：“正是这些更细微的细节，可能有助于我们理解为什么有些珊瑚会白化，而另一些却不会，[即使]它们就长在彼此旁边。”
Every coral colony is cushioned by a thin boundary layer of water whose movement is slowed by friction at the coral’s surface. Researchers assumed that corals were passive with respect to the slow-moving boundary layer, simply relying on natural diffusion through it to provide nutrients and oxygen. Then, in 2014, a team from the Massachusetts Institute of Technology and the Weizmann Institute of Science published a groundbreaking study showing that coral cilia interact with the boundary layer by rapidly whipping about to generate swirls of fresh, oxygenated seawater. Until a decade ago, scientists thought of these cilia merely as brooms that move mucus and sweep away waste particles and other debris. The research not only modeled the tiny vortices created by the cilia for the first time, but also revealed the cilia’s importance for survival and metabolism.
每个珊瑚群落都被一层薄薄的边界水层所包裹，该水层的运动因珊瑚表面的摩擦而减慢。研究人员曾认为，珊瑚对于这种缓慢移动的边界层是被动的，仅仅依靠通过它的自然扩散来提供营养和氧气。然而，2014 年，来自麻省理工学院和魏茨曼科学研究所的一个团队发表了一项开创性研究，表明珊瑚纤毛通过快速摆动与边界层相互作用，从而产生新鲜的、含氧的海水漩涡。直到十年前，科学家们还仅仅把这些纤毛看作是移动粘液、扫除废物颗粒和其他碎屑的“扫帚”。这项研究不仅首次模拟了纤毛产生的微小涡流，还揭示了纤毛对于生存和代谢的重要性。
At first, the microbiologist and environmental engineer Orr Shapiro, who led the 2014 work at MIT as a postdoctoral fellow, was interested in how microbes that infect corals and cause disease follow concentration gradients, a process called chemotaxis. Under the microscope, he noticed something weird: In the boundary layer, particles were swirling around and mixing together—not at all like the passive diffusion he had been expecting. “That was to me, and I think later on to the entire field, sort of a paradigm shift,” said Shapiro, now a researcher at the Volcani Institute in Israel. It became clear that the boundary layer wasn’t static, but rather a dynamic zone, and one where cilia were creating their own turbulence. The realization inspired Shapiro’s team to go off on a tangent, mapping the flow of oxygen to coral tissues via cilia. “It really transformed how we understand this [micro]environment, because suddenly the diffusion is no longer really important,” Shapiro said.
起初，微生物学家兼环境工程师奥尔·夏皮罗（Orr Shapiro）——他在麻省理工学院担任博士后研究员时领导了 2014 年的那项工作——对感染珊瑚并导致疾病的微生物如何遵循浓度梯度（这一过程称为趋化性）感兴趣。在显微镜下，他注意到了一些奇怪的事情：在边界层中，颗粒在旋转并混合在一起，这与他预期的被动扩散完全不同。“对我来说，我想后来对整个领域来说，这算是一种范式转移，”现为以色列沃尔卡尼研究所研究员的夏皮罗说。显而易见，边界层并非静态，而是一个动态区域，纤毛正在其中制造自己的湍流。这一发现启发了夏皮罗的团队转向另一个研究方向，即绘制通过纤毛向珊瑚组织输送氧气的流动图。“它确实改变了我们对这种[微观]环境的理解，因为突然之间，扩散不再那么重要了，”夏皮罗说。
Diffusion is the default route for nutrients traveling through water, but it’s painfully slow. It can take as long as four minutes for oxygen to travel just 1 millimeter. That’s why the fast-moving flows created by cilia are so important: because naturally flowing water slows down near the coral’s surface, and corals consume oxygen faster than diffusion can supply it. It is a system that delivers enough oxygen, despite the cilia’s energy consumption. But there’s a downside: Oxygen dwindles as temperature climbs. That’s when corals run into trouble.
扩散是营养物质在水中传播的默认途径，但它极其缓慢。氧气移动仅仅 1 毫米可能就需要长达四分钟的时间。这就是为什么纤毛产生的快速流动如此重要：因为自然流动的水在珊瑚表面附近会减速，而珊瑚消耗氧气的速度比扩散供应氧气的速度要快。这是一个能够输送足够氧气的系统，尽管纤毛本身也消耗能量。但它有一个缺点：随着温度升高，氧气会减少。这就是珊瑚遇到麻烦的时候。
Scientists have a clear understanding of one thing that happens to corals when water gets too hot: bleaching. As water temperatures rise, a coral’s symbiotic algae become stressed and release molecules that are toxic to the coral in large quantities. To protect itself, the coral expels its own algae—a primary food, energy, and oxygen source—and soon loses its color. It’s a slow death and an increasingly common occurrence as heat waves sweep across the world’s reefs. But sometimes, some corals on a reef bleach while others don’t, and in other cases corals under heat stress die without expelling their algae. An international team of microbiologists, engineers, and physiologists was eager to understand how heat affects cilia, and whether this could explain different types of coral death.
科学家们清楚地了解当水温过高时珊瑚会发生的一件事：白化。随着水温升高，珊瑚的共生藻类会产生压力，并释放出大量对珊瑚有毒的分子。为了保护自己，珊瑚会排出这些藻类——它们是珊瑚主要的食物、能量和氧气来源——并很快失去颜色。这是一个缓慢的死亡过程，随着热浪席卷全球的珊瑚礁，这种情况正变得越来越普遍。但有时，珊瑚礁上的一些珊瑚会白化，而另一些则不会；在其他情况下，处于热应激下的珊瑚在没有排出藻类的情况下就死亡了。一个由微生物学家、工程师和生理学家组成的国际团队渴望了解热量如何影响纤毛，以及这是否能解释不同类型的珊瑚死亡。
“We’re living in a world right now of extreme scenarios,” said Cesar Pacherres, a co-author of the new study and a marine biologist at the University of Copenhagen.
“我们现在生活在一个充满极端情况的世界里，”这项新研究的合著者、哥本哈根大学的海洋生物学家塞萨尔·帕切雷斯（Cesar Pacherres）说。