變色的海蛇尾即使沒有眼睛也能看見

變色的海蛇尾即使沒有眼睛也能看見

The red brittle star doesn't have eyes in the traditional sense. But this marine creature still is able to use vision to find its way through coral reefs thanks to what scientists call a "neat color-changing trick."

紅海蛇尾沒有傳統(tǒng)意義上的眼睛。但是這種海洋生物仍然能夠利用視覺在珊瑚礁中找到自己的路，這要歸功于科學家們所說的“巧妙的變色技巧”。

Photo: Lauren Sumner-Rooney

Related to sea stars and sea urchins, Ophiocoma wendtii lives in the bright reefs of the Caribbean Sea. Earlier, scientists discovered that this brittle star is covered in thousands of light-sensitive cells, but they weren't sure what they were for. New research, published in the journal Current Biology, suggests the brittle star uses its color-changing powers for vision.

與海星和海膽有關的蛇發(fā)座水母生活在加勒比海明亮的珊瑚礁中。早些時候，科學家發(fā)現(xiàn)這顆海蛇尾上覆蓋著數千個感光細胞，但他們不確定這些細胞是用來做什么的。發(fā)表在《當代生物學》雜志上的一項新研究表明，海蛇尾利用其變色能力來獲取視覺。

For years, an international team of researchers has been conducting experiments to test the brittle star's "eyesight."

多年來，一個國際研究小組一直在進行實驗，以測試海蛇尾的“視力”。

"These experiments gave us not only the first evidence that any brittle star is able to 'see', but only the second known example of vision in any animal lacking eyes," study co-author Lauren Sumner-Rooney, a research fellow at Oxford University Museum of Natural History, said in a news release.

牛津大學自然歷史博物館研究員、研究報告的合著者勞倫·薩姆納·魯尼在新聞發(fā)布會上說:“這些實驗不僅為我們提供了‘海蛇尾’能夠‘看見’的第一個證據，而且也為我們提供了第二個已知的‘海蛇尾’能夠‘看見’動物的例子。”

In the experiments, the brittle stars look for areas of contrast. The researchers think that these contrasts in the wild may signify structures that could offer safety from predators.

在實驗中，海蛇尾尋找對比度區(qū)域。研究人員認為，這些在野外的對比可能意味著這些結構可以提供安全的捕食者。

The animals' vision is limited during the day and is nonexistent at night, researchers found.

研究人員發(fā)現(xiàn)，這種動物的視力在白天受到限制，而在晚上則完全不存在。

"We were surprised to find that the responses we saw during the day disappeared in animals tested at night, yet the light-sensitive cells still seemed to be active," said Sumner-Rooney.

薩姆納·魯尼說:“我們驚訝地發(fā)現(xiàn)，我們白天看到的反應在晚上測試的動物身上消失了，但光敏細胞似乎仍然活躍。”

In their experiments, researchers compared O. wendtii to a close relative, Ophiocoma pumila, which is also covered in light sensors but doesn't change colors. The red brittle star turns red during the day, but becomes beige at night. The paler, non-color-changing species failed all the eye tests.

在他們的實驗中，研究人員將O. wendtii與它的近親pumila蛇昏迷進行了比較。紅海蛇尾在白天變紅，晚上變成米黃色。這種顏色較淺、不變色的物種沒有通過所有的視力測試。

"It's a very exciting discovery," said Sumner-Rooney. "It had been suggested 30 years ago that changing colour might hold the key to light-sensitivity in Ophiocoma, so we're very happy to be able to fill in some of the gaps that remained and describe this new mechanism."

“這是一個非常令人興奮的發(fā)現(xiàn)，”薩姆納·魯尼說。“30年前曾有人提出，改變顏色可能是紅海蛇尾對光敏感的關鍵，所以我們很高興能夠填補一些空白，并描述這種新的機制。”