TED演讲：细菌是怎样交流的(4)_在线英语听力室

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　　The reason that Vibrio fischeri is doing that comes from the biology. 费氏弧菌的发光现象来自生物学上的原因。

　　So again, another plug for the animals in the ocean, Vibrio fischeri lives in this squid. 接下来，我们再来看一个海洋生物：费式弧菌寄生在这种乌贼的体内。

　　What you are looking at is the Hawaiian Bobtail Squid, and it's been turned on its back, 你们现在看到的是夏威夷截尾乌贼，这是它的腹侧，

　　and what I hope you can see are these two glowing lobes¹ and these house the Vibrio fischeri cells, 我希望你们看得到，那两个发着光的叶状突起，这里是费式弧菌的寄生之处，

　　they live in there, at high cell number that molecule² is there, and they're making light. 他们居住在这里面。他们分泌的小分子也在这里面，所以它们能够发光。

　　And the reason the squid is willing to put up with these shenanigans is because it wants that light. 这种乌贼之所以愿意接受它们在里面胡作非为，是因为它需要这些亮光。

　　And so the way that this symbiosis³ works is that this little squid lives just off the coast of Hawaii, just in sort of shallow knee-deep water. 这种共存行为的建立基础，是因为这种小乌贼生活在夏威夷的海岸，大概只有膝盖一般深的水里。

　　And the squid is nocturnal, so during the day it buries itself in the sand and sleeps, but then at night it has to come out to hunt. 这种乌贼是夜行性的，因此在白天它们藏在沙子里睡觉，但是到了晚上，它们必须出来猎食。

　　And so on bright nights when there is lots of starlight or moonlight that light can penetrate⁴ the depth of the water the squid lives in, 在有着许多星光与月光的明亮夜晚，这些光线可以照透乌贼所生活的地方，

　　since it's just in those couple feet of water. 因为这里的海水只有数尺深而已。

　　And what the squid has developed is a shutter⁵ that can open and close over this specialized⁶ light organ housing the bacteria. 这种乌贼演化出了一种活叶瓣，可以打开或关闭细菌所寄生的发光器官。

　　And then it has detectors⁷ on its back so it can sense how much starlight or moonlight is hitting its back. 这种乌贼背上有一些感光装置，可以测量有多少月光或星光照在它背上，

　　And it opens and closes the shutter so the amount of light coming out of the bottom -- which is made by the bacterium⁸ 然后调节它的活叶瓣，使从它腹部所放出的光--细菌产生的光，

　　exactly matches how much light hits the squid's back, so the squid doesn't make a shadow. 完全符合照射在乌贼背上的光强度。因此这乌贼就不会产生任何影子。

　　So it actually uses the light from the bacteria to counter-illuminate itself in an anti-predation device 它们使用来自细菌的光，不断调节光线，就像穿上隐身衣，

　　so predators⁹ can't see its shadow, calculate its trajectory¹⁰, and eat it. 使猎食者无法看见它的阴影，计算它的动向，然后吃了它。

　　So this is like the stealth bomber¹¹ of the ocean. 就像是大海中的隐形轰炸机一般。

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收听单词发音

1 lobes
n.耳垂( lobe的名词复数 )；（器官的）叶；肺叶；脑叶
参考例句：
The rotor has recesses in its three faces between the lobes. 转子在其凸角之间的三个面上有凹槽。来自辞典例句 The chalazal parts of the endosperm containing free nuclei forms several lobes. 包含游离核的合点端胚乳部分形成几个裂片。来自辞典例句

2 molecule
n.分子，克分子
参考例句：
A molecule of water is made up of two atoms of hygrogen and one atom of oxygen.一个水分子是由P妈̬f婘̬ 妈̬成的。 This gives us the structural formula of the molecule.这种方式给出了分子的结构式。

3 symbiosis
n.共生（关系），共栖
参考例句：
They live in a symbiosis with governments that they are financing.他们与他们服务的政府互利共存。 The symbiosis between social values and political structure has produced extraordinary achievement.社会价值观念和政治结构的共生现象带来了非凡的成就。

4 penetrate
v.透(渗)入；刺入，刺穿；洞察，了解
参考例句：
Western ideas penetrate slowly through the East.西方观念逐渐传入东方。 The sunshine could not penetrate where the trees were thickest.阳光不能透入树木最浓密的地方。

5 shutter
n.百叶窗；(照相机)快门；关闭装置
参考例句：
The camera has a shutter speed of one-sixtieth of a second.这架照像机的快门速度达六十分之一秒。 The shutter rattled in the wind.百叶窗在风中发出嘎嘎声。

6 specialized
adj.专门的，专业化的
参考例句：
There are many specialized agencies in the United Nations.联合国有许多专门机构。 These tools are very specialized.这些是专用工具。

7 detectors
探测器( detector的名词复数 )
参考例句：
The report advocated that all buildings be fitted with smoke detectors. 报告主张所有的建筑物都应安装烟火探测器。 This is heady wine for experimenters using these neutrino detectors. 对于使用中微子探测器的实验工作者，这是令人兴奋的美酒。来自英汉非文学 - 科技

8 bacterium
n.(pl.)bacteria 细菌
参考例句：
The bacterium possibly goes in the human body by the mouth.细菌可能通过口进入人体。 A bacterium is identified as the cause for his duodenal ulcer.一种细菌被断定为造成他十二指肠溃疡的根源。

9 predators
n.食肉动物( predator的名词复数 )；奴役他人者（尤指在财务或性关系方面）
参考例句：
birds and their earthbound predators 鸟和地面上捕食它们的动物 The eyes of predators are highly sensitive to the slightest movement. 捕食性动物的眼睛能感觉到最细小的动静。来自《简明英汉词典》

10 trajectory
n.弹道，轨道
参考例句：
It is not difficult to sketch the subsequent trajectory.很容易描绘出它们最终的轨迹。 The path followed by a projectile is called its trajectory.抛物体所循的路径称为它的轨道。

11 bomber
n.轰炸机，投弹手，投掷炸弹者
参考例句：
He flew a bomber during the war.他在战时驾驶轰炸机。 Detectives hunting the London bombers will be keen to interview him.追查伦敦爆炸案凶犯的侦探们急于对他进行讯问。

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TED演讲：细菌是怎样交流的(4)