色彩斑斕的珊瑚，可能正在召喚重要的藻類返回家園

色彩斑斕的珊瑚，可能正在召喚重要的藻類返回家園

One of the ways coral reacts to abnormal sea temperatures is by expelling tiny algae that lives in its tissues, a process that drives the type of bleaching events that have devastated Australia’s Great Barrier Reef in recent years. But not all corals respond by turning ghostly white, with some instead becoming shimmering arrays of bright neon colors. The authors of a new study believe this is an attempt to lure the much-needed algae back home.

珊瑚對異常海水溫度的反應方式之一是驅(qū)逐生活在其組織中的微小藻類，這一過程導致了近年來破壞澳大利亞大堡礁的漂白現(xiàn)象。但并不是所有的珊瑚都會變成幽靈般的白色，有些甚至會變成閃爍的霓虹燈陣列。一項新研究的作者認為，這是一種試圖將急需的藻類吸引回家的嘗試。

A lot of the coral species that make up structures like Australia’s Great Barrier Reef survive by way of a delicate symbiotic relationship with this algae, which shelter in their cells and provides them with energy via photosynthesis. When sea temperatures rise, it causes this relationship to break down, with the algae abandoning their homes to leave the coral white, withering and in danger of dying.

構(gòu)成澳大利亞大堡礁等結(jié)構(gòu)的許多珊瑚物種，都是通過與這種藻類微妙的共生關(guān)系存活下來的。這種藻類棲息在它們的細胞中，通過光合作用為它們提供能量。當海水溫度上升時，這種關(guān)系就會破裂，藻類會離開它們的家園，留下白色的珊瑚，枯萎并有死亡的危險。

In what has been a mystery to scientists, however, some of these algae-free coral respond by exhibiting a variety of bright colors instead. To study this phenomenon, scientists at the University of Southampton conducted laboratory experiments at their coral aquarium facility, through which they found these corals produce a type of protective “sunscreen” layer that presents as these colorful displays.

然而，對科學家來說，這一直是個謎，一些沒有藻類的珊瑚反而表現(xiàn)出各種明亮的顏色。為了研究這一現(xiàn)象，南安普敦大學的科學家們在珊瑚水族館進行了實驗室實驗，他們發(fā)現(xiàn)這些珊瑚會產(chǎn)生一種保護性的“防曬”層，就像這些五顏六色的展品一樣。

This is a consequence of a business as usual approach on part of the corals, the team found. In the absence of the all-important algae to absorb light, it bounces around inside the coral tissue to give it its white appearance, But when these corals are able to continue some of their normal functions, this internal light instead boosts the production of colorful photoprotective pigments, which act a lure for the returning algae.

研究小組發(fā)現(xiàn)，這是部分珊瑚礁照常工作的結(jié)果。在沒有最重要的藻類來吸收光的情況下，它會在珊瑚組織內(nèi)反彈，使珊瑚呈現(xiàn)出白色的外觀，但當這些珊瑚能夠繼續(xù)發(fā)揮部分正常功能時，這種內(nèi)部光線反而會促進彩色的光保護色素的產(chǎn)生，這些色素對返回的藻類起到了誘導作用。

“The resulting sunscreen layer will subsequently promote the return of the symbionts,” says Professor Jörg Wiedenmann, head of the University of Southampton’s Coral Reef Laboratory. “As the recovering algal population starts taking up the light for their photosynthesis again, the light levels inside the coral will drop and the coral cells will lower the production of the colorful pigments to their normal level.”

南安普敦大學珊瑚礁實驗室負責人Júrg Wiedemann教授說：“由此產(chǎn)生的防曬層隨后將促進共生體的回歸。”。“隨著恢復中的藻類種群開始重新吸收光進行光合作用，珊瑚體內(nèi)的光照水平將下降，珊瑚細胞將把彩色色素的產(chǎn)生降低到正常水平。”

The scientists believe that corals exhibiting this behavior have most likely experienced mild or short-lived warming events, rather than the type of extreme and drawn-out temperature rises that threaten much of the world’s reefs.

科學家們認為，表現(xiàn)出這種行為的珊瑚最有可能經(jīng)歷溫和或短暫的變暖事件，而不是威脅到世界許多珊瑚礁的那種極端和持久的升溫。

“Bleaching is not always a death sentence for corals, the coral animal can still be alive,” says Dr Cecilia D’Angelo, Lecturer of Molecular Coral Biology at the University of Southampton. “If the stress event is mild enough, corals can re-establish the symbiosis with their algal partner. Unfortunately, recent episodes of global bleaching caused by unusually warm water have resulted in high coral mortality, leaving the world’s coral reefs struggling for survival.”

南安普敦大學分子珊瑚生物學講師塞西莉亞·迪安杰洛博士說:“珊瑚白化并不總是對珊瑚宣判死刑，珊瑚動物仍然可以存活。”“如果壓力事件足夠輕微，珊瑚可以重建與藻類伙伴的共生關(guān)系。”不幸的是，最近異常溫暖的海水導致全球珊瑚白化，導致珊瑚死亡率很高，世界各地的珊瑚礁都在為生存而掙扎。”