变色的海蛇尾即使没有眼睛也能看见

变色的海蛇尾即使没有眼睛也能看见

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."

红海蛇尾没有传统意义上的眼睛。但是这种海洋生物仍然能够利用视觉在珊瑚礁中找到自己的路，这要归功于科学家们所说的“巧妙的变色技巧”。

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.

与海星和海胆有关的蛇发座水母生活在加勒比海明亮的珊瑚礁中。早些时候，科学家发现这颗海蛇尾上覆盖着数千个感光细胞，但他们不确定这些细胞是用来做什么的。发表在《当代生物学》杂志上的一项新研究表明，海蛇尾利用其变色能力来获取视觉。

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

多年来，一个国际研究小组一直在进行实验，以测试海蛇尾的“视力”。

"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.

牛津大学自然历史博物馆研究员、研究报告的合著者劳伦·萨姆纳·鲁尼在新闻发布会上说:“这些实验不仅为我们提供了‘海蛇尾’能够‘看见’的第一个证据，而且也为我们提供了第二个已知的‘海蛇尾’能够‘看见’动物的例子。”

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.

在实验中，海蛇尾寻找对比度区域。研究人员认为，这些在野外的对比可能意味着这些结构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.

研究人员发现，这种动物的视力在白天受到限制，而在晚上则完全不存在。

"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.

萨姆纳·鲁尼说:“我们惊讶地发现，我们白天看到的反应在晚上测试的动物身上消失了，但光敏细胞似乎仍然活跃。”

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.

在他们的实验中，研究人员将O. wendtii与它的近亲pumila蛇昏迷进行了比较。红海蛇尾在白天变红，晚上变成米黄色。这种颜色较浅、不变色的物种没有通过所有的视力测试。

"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."

“这是一个非常令人兴奋的发现，”萨姆纳·鲁尼说。“30年前曾有人提出，改变颜色可能是红海蛇尾对光敏感的关键，所以我们很高兴能够填补一些空白，并描述这种新的机制。”