珊瑚是动物或植物（是动物还是植物）

A colourful coral reef which provides food and protection for marine life.

多彩的珊瑚礁，为海洋生物提供食物和保护。

Coral, a sessile animal, relies on its relationship with plant-like algae to build the largest structures of biological origin on Earth.

珊瑚是动物还是植物？

珊瑚是一种固着的动物，依靠它与类似植物的藻类的关系来建造地球上最大的生物起源结构。

Did you know?

When corals are stressed by changes in conditions such as temperature, light, or nutrients, they expel the symbiotic algae living in their tissues, causing them to turn completely white. When a coral bleaches, it is not dead. Corals can survive a bleaching event, but they are under more stress and are subject to mortality. Coral bleaching is of particular concern today as our climate changes and temperatures rise.

你知道吗？

当珊瑚受到温度、光照或营养物质等条件变化的压力时，它们会排出生活在其组织中的共生藻类，使其完全变白。当珊瑚漂白时，它并没有死亡。珊瑚可以在漂白事件中存活下来，但它们承受着更大的压力，并且容易死亡。随着我们的气候变化和气温上升，珊瑚漂白问题今天尤其令人关注。

Corals are sessile, which means that they permanently attach themselves to the ocean floor, essentially "taking root" like most plants do. We certainly cannot recognize them by their faces or other distinct body parts, as we can most other animals.

珊瑚是固着的，这意味着它们永久地附着在海底，基本上像大多数植物一样“扎根”。我们当然不能像大多数其他动物那样，通过它们的脸或其他不同的身体部位来识别它们。

So what exactly are corals?

Corals actually comprise an ancient and unique partnership, called symbiosis, that benefits both animal and plant life in the ocean. Corals are animals, though, because they do not make their own food, as plants do. Corals have tiny, tentacle-like arms that they use to capture their food from the water and sweep into their inscrutable mouths.

那么珊瑚到底是什么呢？

珊瑚实际上是一种古老而独特的伙伴关系，称为共生关系，对海洋中的动植物都有利。珊瑚是动物，因为它们不像植物那样自己制造食物。珊瑚有触手般的小手臂，用来捕捉水中的食物，并将其伸入难以理解的嘴里。

Most structures that we call "coral" are, in fact, made up of hundreds to thousands of tiny coral creatures called polyps. Each soft-bodied polyp—most no thicker than a nickel—secretes a hard outer skeleton of limestone (calcium carbonate) that attaches either to rock or the dead skeletons of other polyps.

事实上，我们称之为“珊瑚”的大多数结构是由成百上千的珊瑚虫组成的。每一个软体水螅体的厚度大多不超过一个镍，分泌一个坚硬的石灰石（碳酸钙）外骨骼，附着在岩石或其他水螅体的死骨骼上。

In the case of stony or hard corals, these polyp conglomerates grow, die, and endlessly repeat the cycle over time, slowly laying the limestone foundation for coral reefs and giving shape to the familiar corals that reside there. Because of this cycle of growth, death, and regeneration among individual polyps, many coral colonies can live for a very long time.

在石质或硬珊瑚的情况下，这些聚脂砾岩生长、死亡，并随着时间不断地重复循环，慢慢地为珊瑚礁铺设石灰岩地基，并给居住在那里的熟悉珊瑚提供形状。由于珊瑚虫个体之间的生长、死亡和再生循环，许多珊瑚群落可以存活很长时间。

虫黄藻Zooxanthella

Most corals contain algae called zooxanthellae (pronounced zo-UH-zan-thuh-lay), which are plant-like organisms. Residing within the coral's tissues, the microscopic algae are well protected and make use of the coral's metabolic waste products for photosynthesis, the process by which plants make their own food.

大多数珊瑚都含有一种名为虫黄藻（zooxanthellae，发音zo-UH-zan-thuh-lay）的藻类，这是一种类似植物的生物。这些微小的藻类生活在珊瑚的组织中，受到很好的保护，它们利用珊瑚的代谢废物进行光合作用，光合作用是植物自己制造食物的过程。

珊瑚藻

The corals benefit, in turn, as the algae produce oxygen, remove wastes, and supply the organic products of photosynthesis that corals need to grow, thrive, and build up the reef.

珊瑚反过来受益，因为藻类产生氧气，清除废物，并提供珊瑚生长、繁荣和建造珊瑚礁所需的光合作用有机产物。

More than merely a clever collaboration that has endured between some of the tiniest ocean animals and plants for some 25 million years, this mutual exchange is the reason why coral reefs are the largest structures of biological origin on Earth, and rival old-growth forests in the longevity of their ecological communities.

珊瑚礁不仅仅是一些最小的海洋动植物之间的一种聪明的合作，已经持续了大约2500万年，这种相互交流是珊瑚礁成为地球上最大的生物起源结构的原因，也是在其生态群落的寿命方面与老森林相抗衡的原因。