VOA慢速英语20116 是一种“唱情歌”的鱼？（在线收听）

A Fish That 'Sings' Love Songs? 是一种“唱情歌”的鱼？

This is the sound of a fish "singing:"

这是鱼“唱歌”的声音：嗯。。。

It is a male fish — a plainfin midshipman, to be exact — from the Pacific Ocean.He is singing, or humming, a love song to get female fish to come and visit the nest he built for their eggs.

这是一条雄性鱼-确切的说是来自太半洋的珍蟾鱼。它在唱或哼一首情歌，让雌性鱼来拜访它为产卵而筑造的爱巢。

Scientists have wanted to know why the male plainfin midshipman sings only at night.A study published in the journal Current Biology provides some answers.

科学家们想知道为什么雄性珍蟾鱼只在晚上唱歌。发表在《当代生物学杂志》上的一项研究提供了部分答案。

Laboratory experiments showed that the fish’s song, that low, fog-horn-like sound, is controlled partly by a hormone, melatonin.

实验室实验表明，鱼的歌声低沉，如雾号的声音，部分是由褪黑激素控制的。

Hormones are natural substances that influence how bodies grow or develop.In the human body, melatonin tells us when it is time to sleep.

激素是一类天然物质，影响身体的生长和发育。在人体中，褪黑激素掌控我们的睡眠时间。

Andrew Bass is a professor of neurobiology and behavior at Cornell University in New York State.For nearly 30 years, he has been studying the plainfin midshipman, and the sounds they make.

Andrew Bass是纽约州康奈尔大学神经生物学和行为学的教授。近30年来，他一直在研究珍蟾鱼和他们的声音。

“It was always remarkable how right after nightfall, if you are recording from a bunch of nests in a bay, the bay just comes alive with this sound.It’s like it suddenly turns on at night...”

“夜幕降临时刻总是引人注目，如果你正在记录海湾的群巢，海湾伴随着声音变得生机勃勃。就像黑夜中突然开灯。”

Plainfin midshipmen are olive-brown in color. They grow to be up to 38 centimeters long.

珍蟾鱼呈橄榄褐色。他们长大后有38厘米长。

The fish gets its name from rows of organs lined up on its underside.These rows are bio-luminescent.They produce light and shine in the water.

该鱼因身下有一排排的器官而得名。这些排是可以生物发光的。它们在水里发光。

Long ago, people thought they looked like the buttons on navy clothes.

很久以前，人们认为他们看起来像海军衣服上的按钮。

In the late spring and summer, the males move from waters deep in the ocean to more shallow waters close to land.There they build nests for females to leave their eggs under rocky shelters.

在春末和夏季，雄性从深海里的水域移到靠近陆地的更浅水域。它们在那里为雌性建立巢穴，在岩石的庇护所下产卵后离开。

Then, during the night, the males produce their sounds.Often a group of them gather together and start humming.

然后，在夜间，雄性发出声音。通常，它们群体聚集在一起，开始哼唱。

But how do they make these sounds?

但是，它们如何发出这些声音？

Unlike people speaking, or birds singing, you cannot see the fish making the sound.It comes from organs inside.Their gas-filled swim bladder and their vocal muscles help them sing.

不像人们说话，或者鸟唱歌，你不能看到鱼发出声音的动作。它来自器官内。它们的充气的鱼鳔以及声带肌帮助它们唱歌。

Bass says the vocal muscles are hidden deep inside the fishes’ bodies.

Bass说，声带肌隐藏在鱼身体的深处。

“And they contract those muscles at very high rates, and that vibrates the swim bladder,and that in turn generates a vibration in the surrounding water that makes the sound.”

“它们以非常高的速度收缩肌肉，从而振动鱼鳔，在周围水域相应地产生振动，发生声音。”

They can make that sound, non-stop, for hours at a time.But once a female arrives, mating begins, and she leaves her eggs, the male stops singing for the night.It is the male that then watches over the eggs until they hatch — and the young fish can swim on their own.

它们可以一次性数小时不间断发出声音。但一旦雌性到来，开始交配，雌性产卵后离开，夜晚雄性停止唱歌。雄性会一直守护着卵，直到幼鱼孵化并可以自己游泳。

The fish experiments were done in a Cornell laboratory by then-student Ni Feng, who is now at Yale University.It was her idea to study how melatonin affects the fish.The researchers had no idea how the hormone might affect the fishes’ ability to sing and hum.

在康奈尔实验室进行的实验是由当时的学生Ni Feng做的，Ni Feng目前在耶鲁大学学习。研究褪黑激素对鱼的影响是她的点子。研究人员不知道激素会如何影响鱼哼唱的能力。

The fish were kept in rooms where lighting could be controlled.When it was always dark, the fish hummed as they would at night.They followed their internal timing or circadian rhythm.

这些鱼被保存在可以控制灯光的房间里。房间昏暗时，鱼就像是在晚上，发出嗡嗡声。它们遵循内部时间或昼夜节律。

But in bright lighting, a condition that lowers melatonin production, humming was suppressed.When kept in normal light, but given a melatonin replacement, they continued to hum but at unpredictable times.

但明亮灯光降低褪黑激素的产生时，嗡嗡声被抑制。当保持正常的光，但给予褪黑激素替代品，它们继续嗡嗡声，但时间不可预知。

So unlike humans, and even birds, the melatonin did not put the fish to sleep.It had just the opposite effect.

所以不像人类，甚至鸟类，褪黑激素没有让鱼睡觉。它有相反的效果。

Andrew Bass says the study shows how “incredibly versatile” hormones are.

Andrew Bass说，这项研究显示了激素的功能多么“令人难以置信”。

“So here we study melatonin in our animal, right?And instead of suppressing calling, or putting them to sleep, essentially, it actually somewhat acts as a stimulant.Again, it’s the “go” signal that says ok, make more hums...”

“所以，我们在研究我们动物的褪黑激素，对吗？”然而褪黑激素起到的并不是抑制作用，或让它们睡眠，基本上，它实际上有点像一种兴奋剂的作用。再次，这是“开始”的信号，表示可以，发出更多的哼哼声…”

He says that by studying how different animals react to melatonin, researchers will get a better understanding of how it works.

他表示，通过研究不同的动物对褪黑激素的反应，研究人员将更好的理解它是如何工作的。

“We will reveal very fundamental mechanisms of just how this hormone in fact controls daily sleep/wake cycles in all animals.”

“我们将揭示这一激素是如何控制所有动物的日常睡眠/觉醒周期的基本机制。”

The midshipman fish are not the only ones making sounds.In fact, long ago, fishermen would listen carefully to hear where the fish were.Bass says he even found a report written in 1924 about the plainfin midshipman and how they hum at night.

珍蟾鱼不是唯一能发出声音的鱼类。事实上，很久以前，渔民会仔细听，来判断鱼在哪里。Bass说，他甚至发现了一个1924年写的关于珍蟾鱼以及它们晚上如何哼唱的报告。

In the 1980s, people living on houseboats along the California coast did not know what to make of those sounds.Bass said they thought the sound came from either an underwater power line, a nearby water treatment center, a U.S. Navy experiment,or maybe even beings from other planets.

20世纪80年代，生活在加利福尼亚沿岸的船屋上的人不知道该那些声音是什么。Bass说，他们认为声音来自水下电源线，附近的水处理中心，美国海军实验，甚至可能来自其他行星的生命。

The boat owners found out the sound was coming from the male midshipman, looking for love in the night.

船的主人发现声音来自男性学员，在夜晚寻爱。

Like whales and dolphins, other sea creatures, the midshipman fish make different kinds of sounds for social communication.For example, the sound they make when protecting their nests from possible invaders is different than the one they make when calling a mate.

像鲸鱼和海豚其他海洋生物，珍蟾鱼发出各种不同的声音进行社会沟通。例如，当防护入侵者进入它们的巢穴时，它们发出的声音与呼唤伴侣时不同。

Bass says that in the end, humans and other animals are similar in certain behaviors—in this case, the ability to produce sounds.He says these fish, and the things he learns about them, never cease to amaze him.

Bass表示，最终，人类和其他动物在某些行为上是相似的，比如在发出声音的能力的情况。他表示，这些鱼，以及他了解到的有关它们的信息，让他震惊不已。

Words in This Story

nest – n. a place where an animal or insect lives and usually lays eggs or takes care of its young

hormone – n. natural substances that influence how bodies grow or develop

bio-luminescent – adj. something that glows and produce light in the water

swim bladder – n. a gas-filled organ in fish that help them move up or down in the water

larynx – n. muscles in a human’s throat that produce sound, also called a “voice box”

vibrate – v. to move back and forth or from side to side with very short, quick movements

hatch – v. to come out of an egg

circadian rhythm – n. physical, mental and behavioral changes that follow a 24-hour cycle, mostly connected to light and darkness in an organism’s environment

amaze – v. to surprise and sometimes confuse someone very much