科学美国人60秒 SSS 生物发光帮助猎物避开饥饿海豹

This is Scientific American's 60-second Science. I'm Jason Goldman.

这里是科学美国人——60秒科学。我是杰森·古德曼。

Deep in the inky depths of what's called the ocean's mesopelagic zone, more than 500 meters below the surface,

在海面以下500多米被称为海洋中层带的漆黑深处，

the main source of light is not the sun—even during the day.

主要光源也不是阳光，即使在白天也是如此。

Most of the light comes instead from bioluminescent organisms, creatures that produce their own light.

大多数光线来自生物发光的有机体，即自已产生光的生物。

It's in these dark depths that southern elephant seals love to feast on squids and fish.

正是在这些黑暗的深处，南象海豹开心地享用乌贼和鱼。

"Initially¹ we wanted to know how elephant seals find their prey² in the dark."

“最初我们想知道南象海豹如何在黑暗中找到猎物。”

Pauline Goulet from the University of St. Andrews Sea Mammal Research Unit.

圣安德鲁斯大学海洋哺乳动物研究部的波琳·古莱特说到。

Thanks to data-logging technology, researchers have a fairly good handle on how far elephant seals travel to feed—and how long and how deep they dive.

得益于数据记录技术，研究人员对南象海豹的觅食距离、下潜距离和深度有了相当好的了解。

But nobody really knew how they find their prey in the darkness. Do they track the lights? Or is something else going on?

但没有人知道他们如何在黑暗中找到猎物。它们是追踪光线吗？还是有别的方法？

"So we built a sensor³ that could pick up flashes produced by animals that were being hunted by the elephant seal,

“我们制造了一个传感器，可以接收到被南象海豹捕获的动物发出的闪光，

because we thought that elephant seals might be looking for that light to catch a snack."

因为我们当时认为南象海豹可能通过追寻光来捕食。”

But it turned out that the fish actually used their bioluminescence to disorient seals after the seals began their attack.

但结果发现，鱼类实际上是在海豹开始攻击后，利用自已的生物发光来让海豹迷失方向。

"The thing is it seemed that the flashing prey were harder to catch than the nonflashing prey—

“关键是闪光的猎物似乎比不闪光的猎物更难捕捉，

which we found out by looking at the duration of the chase, which was longer for flashing prey."

我们通过观察追捕的持续时间发现，追捕闪光猎物要花更长时间。”

The fish flash was always emitted just after the seal launched an attack, making it a defensive⁴, reactive maneuver⁵ to distract the seals.

鱼总是在南象海豹开始攻击后再发出闪光，使其成为一种防御性的、反应性的策略，以分散海豹的注意力。

But at least one seal learned to turn that liability into a hunting strategy.

但至少有一只海豹学会了将这种不利因素转化为捕猎策略。

"This seal appeared to be a master in catching⁶ the flashing prey,

“这只海豹似乎是捕猎闪光猎物的高手，

because each time it tried to catch a prey, first it would do this little head movement that was probably mechanically sensed by the prey.

因为每次它试图捕获猎物时，它会先稍微动下头部，这很可能被猎物机械性地感觉到。

Then it would induce the prey to flash, because the prey reacts to this approaching predator⁷."

之后它会诱导猎物闪光，因为猎物会对靠近的捕食者做出反应。”

This seal would twitch⁸ her head, see where the light came from and only then start the chase.

这只海豹会晃动头部，看看光来自哪里，然后才开始追捕。

So even if some seals can use bioluminescence as a way to find food, for most the light is a distraction⁹.

因此，即使有些海豹可以利用生物发光来寻找食物，但对大多数海豹来说，光会分散它们的注意力。

Goulet thinks that seals probably rely more on their whiskers to sense the movements their prey make in the water.

古莱特认为海豹可能更依赖它们的胡须来感知猎物在水中的动作。

"It's just a step forward into understanding what's happening in these depths, in this ecosystem¹⁰ that we don't really know much about—especially in the Southern Ocean."

“这只是进一步了解在这些海底深处、这种生态系统中发生的情况，我们对二者都不太了解，尤其是南大洋的情况。”

Thanks for listening for Scientific American's 60-second Science. I'm Jason Goldman.

谢谢大家收听科学美国人——60秒科学。我是杰森·古德曼。

1 initially   

adv.最初，开始

参考例句：

• The ban was initially opposed by the US.这一禁令首先遭到美国的反对。
• Feathers initially developed from insect scales.羽毛最初由昆虫的翅瓣演化而来。

2 prey   

n.被掠食者，牺牲者，掠食；v.捕食，掠夺，折磨

参考例句：

• Stronger animals prey on weaker ones.弱肉强食。
• The lion was hunting for its prey.狮子在寻找猎物。

3 sensor   

n.传感器，探测设备，感觉器（官）

参考例句：

• The temperature sensor is enclosed in a protective well.温度传感器密封在保护套管中。
• He plugged the sensor into a outlet.他把传感器插进电源插座。

4 defensive   

adj.防御的；防卫的；防守的

参考例句：

• Their questions about the money put her on the defensive.他们问到钱的问题，使她警觉起来。
• The Government hastily organized defensive measures against the raids.政府急忙布置了防卫措施抵御空袭。

5 maneuver   

n.策略[pl.]演习；v.(巧妙)控制；用策略

参考例句：

• All the fighters landed safely on the airport after the military maneuver.在军事演习后，所有战斗机都安全降落在机场上。
• I did get her attention with this maneuver.我用这个策略确实引起了她的注意。

6 catching   

adj.易传染的，有魅力的，迷人的，接住

参考例句：

• There are those who think eczema is catching.有人就是认为湿疹会传染。
• Enthusiasm is very catching.热情非常富有感染力。

7 predator   

n.捕食其它动物的动物；捕食者

参考例句：

• The final part of this chapter was devoted to a brief summary of predator species.本章最后部分简要总结了食肉动物。
• Komodo dragon is the largest living lizard and a fearsome predator.科摩多龙是目前存在的最大蜥蜴，它是一种令人恐惧的捕食性动物。

8 twitch   

v.急拉，抽动，痉挛，抽搐；n.扯，阵痛，痉挛

参考例句：

• The smell made my dog's nose twitch.那股气味使我的狗的鼻子抽动着。
• I felt a twitch at my sleeve.我觉得有人扯了一下我的袖子。

9 distraction   

n.精神涣散，精神不集中，消遣，娱乐

参考例句：

• Total concentration is required with no distractions.要全神贯注，不能有丝毫分神。
• Their national distraction is going to the disco.他们的全民消遣就是去蹦迪。

10 ecosystem   

n.生态系统

参考例句：

• This destroyed the ecosystem of the island.这样破坏了岛上的生态系统。
• We all have an interest in maintaining the integrity of the ecosystem.维持生态系统的完整是我们共同的利益。