關于動物的14個誤解 個個讓你驚掉下巴[1]
![關于動物的14個誤解 個個讓你驚掉下巴[1]](http://zixueku.oss-cn-beijing.aliyuncs.com/peitu/xiezuo/xinzuo-21.jpg)
聽說，星巴克有一種飲料是用小蟲子的尸體做成的，香草冰淇淋里有海貍屁股的分泌物，狗和貓都是色盲，蝙蝠是瞎子？不要再散播謠言了，聽科學家來一一澄清誤解。
The animal kingdom is home to one remarkable fact after another.
動物王國里充滿了一個又一個神奇的事實。
To name a few: Sperm whales can hold their breath for an hour, the most venomous animal on Earth is a snail, and tiny freshwater hydras can live so long they may as well be immortal.
舉幾個例子來說：抹香鯨可以屏住呼吸一個小時，地球上毒性最大的動物是蝸牛，微小的淡水水螅屬動物可以活很長很長時間，幾乎可以說是長生不老。
But for each surprisingly true assertion about animals, there's invariably another that's exaggerated, misguided, or just plain wrong.
但是每一個關于動物的驚人真相身邊總是伴隨著另一個被夸大、誤導或完全錯誤的言論。
下面是幾個關于動物最常見的誤解，以及它們背后的真相——或者最接近真相的認識。
MYTH: Beaver butt secretions are in your vanilla ice cream and other foods.
誤解一：香草冰淇淋和其他食品里有海貍屁股的分泌物。
You've probably heard that a secretion called castoreum, isolated from the anal gland of a beaver, is used in flavourings and perfumes.
你大概聽說過有一種叫作海貍香的分泌物，這是從海貍的肛腺中分離出來的物質，用于制作調味料和香水。
But castoreum is so expensive, at up to $70 per pound of anal gland (the cost to humanely milk castoreum from a beaver is likely even higher), that it's unlikely to show up in anything you eat.
但是海貍香非常昂貴，每磅肛腺價格高達70美元（如果用人道的方式從海貍屁股汲取海貍香花費很可能更高），所以海貍香在你食用的東西里出現是不大可能的。
In 2011, the Vegetarian Resource Group wrote to five major companies that produce vanilla flavoring and asked if they use castoreum. The answer: According to the Federal Code of Regulations, they can't. (The FDA highly regulates what goes into vanilla flavoring and extracts.)
2011年，素食資源團體寫信給五個生產香草調味料的大公司，問他們是否使用了海貍香。答案是：根據美國聯邦法規，他們不能這么做。（美國聯邦法規對用于香草調味料和香草精的物質有嚴格規定。）
It's equally unlikely you'll find castoreum in mass-marketed goods, either.
同樣，在大眾化商品中找到海貍香也是不太可能的。
MYTH: Dogs and cats are colourblind.
誤解二：狗和貓都是色盲。
Dogs and cats have much better colour vision than we thought.
狗和貓對顏色的辨別力比我們想的強多了。
Both dogs and cats can see in blue and green, and they also have more rods – the light-sensing cells in the eye – than humans do, so they can see better in low-light situations.
狗和貓都可以辨別藍色和綠色，而且它們的視桿細胞（眼睛里的感光細胞）比人類還多，在弱光環境下視力比人類更好。
This myth probably comes about because each animal sees colours differently than humans.
這個誤解很可能是源于每種動物看到的顏色都和人類不同。
Reds and pinks may appear more green to cats, while purple may look like another shade of blue.
紅色和粉色在貓看來可能更綠一些，而紫色也許在貓眼里是另一種藍色。
Dogs, meanwhile, have fewer cones – the colour-sensing cells in the eye – so scientists estimated that their colour vision is only about 1/7th as vibrant as ours.
與此同時，狗的視錐細胞（眼睛里的感色細胞）更少，所以科學家估計狗對顏色的辨別力只有人類的七分之一。
MYTH: Humans evolved from chimpanzees.
誤解三：人類是從大猩猩進化而來的。
Chimps and humans share uncanny similarities, not the least of which is our DNA – about 98.8 percent is identical.
大猩猩和人類確實是有很多詭異的相似之處，尤其是DNA——大約有98.8%是相同的。
However, evolution works as incremental genetic changes add up through many generations. Chimps and humans did share a common ancestor between 6 and 8 million years ago but a lot has changed since then.
但是，進化是經歷許多代累積產生的基因改變。大猩猩和人類確實在600萬至800萬年前擁有同一個祖先，但是自那以后很多事情都發生了變化。
Modern chimps evolved into a separate (though close) branch of the ape family tree.
現代大猩猩進化成了猿猴大家族的一個獨立（盡管關系很近的）分支。
MYTH: Lemmings jump off cliffs in mass suicides.
誤解四：旅鼠會集體跳崖自殺。
Lemmings do not commit mass suicide.
旅鼠并不會集體自殺。
During their migrations, or if they wander into an area they are unfamiliar with, they sometimes do fall off cliffs.
在遷徙過程中，如果旅鼠走到了一塊不熟悉的地方，它們有時確實會跌下懸崖。
No one knows exactly when the myth started, but a 1958 Disney video called White Wilderness, which won an Oscar for best documentary feature, has emerged over the years as the likeliest suspect.
沒人知道這個誤解是從哪里開始的，但是曾獲得奧斯卡獎的1958年迪士尼紀錄片《白色荒野》極有可能是這些年來這種誤解的起源。
MYTH: Bats are blind.
誤解五：蝙蝠是瞎子。
Being "blind as a bat" means not being blind at all.
“和蝙蝠一樣瞎”的意思是一點也不瞎。
While many use echolocation to navigate, all of them can see.
盡管很多蝙蝠用回聲定位能力來導航，但所有的蝙蝠都能看得見。
MYTH: Ostriches hide by putting their heads in the sand.
誤解六：鴕鳥想躲起來就把頭埋在沙子里。
Ostriches do not stick their heads in the sand when threatened. In fact, they don't bury their heads at all.
鴕鳥在受到威脅的時候不會把頭埋在沙子里。事實上，它們根本就不會把頭埋起來。
When threatened, ostriches sometimes flop on the ground and play dead.
在受到威脅時，鴕鳥有時會倒在地上裝死。
MYTH: People get warts from frogs and toads.
誤解七：人們碰到青蛙和蟾蜍會長疣子。
Frogs or toads won't give you warts, but shaking hands with someone who has warts can.
青蛙或蟾蜍不會讓你長疣子，但是和長疣的人握手會讓你長疣子。
The human papillomavirus is what gives people warts, and it is unique to humans.
讓人長疣子的是乳頭瘤病毒，這也是人類獨有的。
MYTH: Sharks can smell a drop of blood from miles away.
誤解八：鯊魚在幾英里外可以聞到一滴血的氣味。
This one is a big exaggeration. Jaws is not coming for you from across the ocean if you bleed in the water.
這個就太夸張了。如果你在海里流血，鯊魚不會從海的那一頭游過來吃你。
Shark have a highly enlarged brain region for smelling odours, allowing some of the fish to detect as little as 1 part blood per 10 billion parts water – roughly a drop in an Olympic-size swimming pool.
鯊魚大腦中有一塊特別大的區域和聞氣味有關，這讓一些鯊魚能夠覺察到100億份水中的一份血——大約相當于奧運會游泳池中的一滴血。
But the ocean is much, much, much bigger and it takes a while for odor molecules to drift. On a very good day when the currents are favourable, a shark can smell its prey from a few football fields away – not miles.
但是海洋比游泳池要大的多得多，而且氣味分子要傳過去也需要一段時間。如果天氣好，洋流方向又有利的話，鯊魚可以聞到幾個足球場面積以外的獵物——但不是幾英里。
MYTH: Giraffes sleep for only 30 minutes a day.
誤解九：長頸鹿每天只睡30分鐘。
Giraffes have fairly normal sleeping patterns, as far as diurnal animals go.
在白天活動的動物當中，長頸鹿的睡眠模式很正常。
To debunk this one, researchers closely monitored a herd of five adult and three young giraffes for 152 days, counting all of their naps and deep sleeps. The animals typically slept overnight and napped in the afternoon (sound familiar?).
為了破除這個誤解，研究人員在152天的時間里密切監視了五頭成年長頸鹿和三頭幼年長頸鹿，計算了它們打盹和深度睡眠的時間。長頸鹿通常在晚上睡覺，在下午小睡。（聽上去是不是很熟悉？）
In total, each giraffe slept about 4.6 hours every day.
總體而言，每頭長頸鹿每天大約睡4.6個小時。
MYTH: There are bugs in your strawberry Frappuccino.
誤解十：你的草莓星冰樂里有小蟲子。
This one used to be true – but not anymore.
以前是這樣的，但現在不是了。
Before April 2024, Starbucks' strawberry Frappuccino contained a dye made from the ground-up bodies of thousands of tiny insects, called cochineal bugs or Dactylopius coccus.
在2024年4月之前，星巴克的草莓星冰樂里含有一種用數千條小蟲子身體碾碎做成的染料，這種蟲子叫胭脂蟲。
Farmers in South and Central America make a living harvesting (and pulverising) the bugs that go into the dye. Their crushed bodies produce a deep red ink that is used as a natural food colouring, which was called "cochineal red" but is now called "carmine colour."
美洲南部和中部的農民以抓捕和碾碎胭脂蟲做染料為生。胭脂蟲磨碎的身體會產生一種深紅色的染料，用來做天然的食品著色劑，這種紅色過去叫“胭脂蟲紅”，不過現在叫洋紅色。
Starbucks stopped using carmine colour in their strawberry Frappuccinos in 2024. But the dye is still used in thousands of other food products – from Nerds candies to grapefruit juice. Not to mention cosmetics, like lovely shades of red lipstick.
2024年星巴克停止在草莓星冰樂里放胭脂蟲染色劑。但是這種染料仍然用在數千種其他食品中——從Nerds糖果到葡萄汁。更別提化妝品了，比如各種美麗色調的口紅。
MYTH: Sharks don't get cancer.
誤解十一：鯊魚不會得癌癥。
Back in 2024, researchers reported a huge tumour growing out of the mouth of a great white shark, and another on the head of a bronze whaler shark.
2024年，研究人員曾報告稱在一頭大白鯊的口中發現一顆巨大的腫瘤，并在另一頭短尾真鯊的頭上也發現了一顆腫瘤。
And those aren't the only cases of shark cancers: Other scientists have reported tumours in dozens of different shark species.
而且，這并不是鯊魚得癌癥的特例：其他科學家也報告過幾十種不同鯊魚出現的腫瘤。
The myth that sharks don't get cancer was reportedly created by William Lane to sell shark cartilage as a cancer treatment.
認為鯊魚不會得癌癥的誤解據說是威廉?萊恩制造的，他試圖將鯊魚軟骨作為抗癌食物售賣。
MYTH: Goldfish can't remember anything for longer than a second.
誤解十二：金魚對任何事情的記憶都不超過一秒。
Goldfish actually have pretty good memories.
金魚其實記憶力相當好。
They can remember things for months, not seconds like many people say.
它們對事物的記憶力可長達數月，而不像許多人所說的只有數秒。
MYTH: Humans got HIV because someone had sex with a monkey.
誤解十三：人類得艾滋病是因為有人和猴子發生性關系。
The human immunodeficiency virus, or HIV, almost certainly didn't jump to humans through human-monkey sex.
人體免疫缺損病毒，即艾滋病毒，基本可以肯定不是通過人和猴子的性交傳播給人類的。
Based on the virus' genetic similarity to a strain of simian immunodeficiency virus, or SIV, that infects chimpanzees, most experts think the virus jumped to humans through hunting primates for bush-meat food.
基于艾滋病毒與黑猩猩之間傳播的一種猿猴免疫缺損病毒的基因相似性，多數專家認為該病毒是通過獵殺靈長類動物以獲取野味食物而傳播給人類的。
This interaction may have led to blood-to-blood contact – perhaps through an open cut on the hunter – and the transfer of a new strain that could silently infect people.
在捕獵過程中可能會有血液接觸——也許是通過獵人身上的一道傷口——從而導致人類不知不覺地傳染上了這種新疾病。
MYTH: Any shark that stops swimming will suffocate and die.
誤解十四：停止游泳的鯊魚都會窒息而死。
You often hear sharks can breathe only when swimming pushes water over their gills.
你經常聽說鯊魚只有在游泳時才能呼吸，因為游起來時水才能從魚鰓流出。
That's true of a lot of sharks, but many others – like bottom-dwelling nurse sharks – can pump oxygen-rich water over their gills without swimming.
很多鯊魚都是如此，但也有很多其他鯊魚——比如住在海底的護士鯊——就算不游泳，富含氧氣的水也可以從魚鰓流出。
All sharks lack swim bladders, however, so if they stop swimming they will sink to the bottom. Luckily a shark's body is incompressible and rapid descents or ascents don't harm them.
但是，所有的鯊魚都沒有魚鰾，所以如果不游泳的話他們就會沉到海底。幸運的是，鯊魚的身體不會被壓縮，迅速的沉降和上浮都不會傷害到它們。
聽說，星巴克有一種飲料是用小蟲子的尸體做成的，香草冰淇淋里有海貍屁股的分泌物，狗和貓都是色盲，蝙蝠是瞎子？不要再散播謠言了，聽科學家來一一澄清誤解。
The animal kingdom is home to one remarkable fact after another.
動物王國里充滿了一個又一個神奇的事實。
To name a few: Sperm whales can hold their breath for an hour, the most venomous animal on Earth is a snail, and tiny freshwater hydras can live so long they may as well be immortal.
舉幾個例子來說：抹香鯨可以屏住呼吸一個小時，地球上毒性最大的動物是蝸牛，微小的淡水水螅屬動物可以活很長很長時間，幾乎可以說是長生不老。
But for each surprisingly true assertion about animals, there's invariably another that's exaggerated, misguided, or just plain wrong.
但是每一個關于動物的驚人真相身邊總是伴隨著另一個被夸大、誤導或完全錯誤的言論。
下面是幾個關于動物最常見的誤解，以及它們背后的真相——或者最接近真相的認識。
MYTH: Beaver butt secretions are in your vanilla ice cream and other foods.
誤解一：香草冰淇淋和其他食品里有海貍屁股的分泌物。
You've probably heard that a secretion called castoreum, isolated from the anal gland of a beaver, is used in flavourings and perfumes.
你大概聽說過有一種叫作海貍香的分泌物，這是從海貍的肛腺中分離出來的物質，用于制作調味料和香水。
But castoreum is so expensive, at up to $70 per pound of anal gland (the cost to humanely milk castoreum from a beaver is likely even higher), that it's unlikely to show up in anything you eat.
但是海貍香非常昂貴，每磅肛腺價格高達70美元（如果用人道的方式從海貍屁股汲取海貍香花費很可能更高），所以海貍香在你食用的東西里出現是不大可能的。
In 2011, the Vegetarian Resource Group wrote to five major companies that produce vanilla flavoring and asked if they use castoreum. The answer: According to the Federal Code of Regulations, they can't. (The FDA highly regulates what goes into vanilla flavoring and extracts.)
2011年，素食資源團體寫信給五個生產香草調味料的大公司，問他們是否使用了海貍香。答案是：根據美國聯邦法規，他們不能這么做。（美國聯邦法規對用于香草調味料和香草精的物質有嚴格規定。）
It's equally unlikely you'll find castoreum in mass-marketed goods, either.
同樣，在大眾化商品中找到海貍香也是不太可能的。
MYTH: Dogs and cats are colourblind.
誤解二：狗和貓都是色盲。
Dogs and cats have much better colour vision than we thought.
狗和貓對顏色的辨別力比我們想的強多了。
Both dogs and cats can see in blue and green, and they also have more rods – the light-sensing cells in the eye – than humans do, so they can see better in low-light situations.
狗和貓都可以辨別藍色和綠色，而且它們的視桿細胞（眼睛里的感光細胞）比人類還多，在弱光環境下視力比人類更好。
This myth probably comes about because each animal sees colours differently than humans.
這個誤解很可能是源于每種動物看到的顏色都和人類不同。
Reds and pinks may appear more green to cats, while purple may look like another shade of blue.
紅色和粉色在貓看來可能更綠一些，而紫色也許在貓眼里是另一種藍色。
Dogs, meanwhile, have fewer cones – the colour-sensing cells in the eye – so scientists estimated that their colour vision is only about 1/7th as vibrant as ours.
與此同時，狗的視錐細胞（眼睛里的感色細胞）更少，所以科學家估計狗對顏色的辨別力只有人類的七分之一。
MYTH: Humans evolved from chimpanzees.
誤解三：人類是從大猩猩進化而來的。
Chimps and humans share uncanny similarities, not the least of which is our DNA – about 98.8 percent is identical.
大猩猩和人類確實是有很多詭異的相似之處，尤其是DNA——大約有98.8%是相同的。
However, evolution works as incremental genetic changes add up through many generations. Chimps and humans did share a common ancestor between 6 and 8 million years ago but a lot has changed since then.
但是，進化是經歷許多代累積產生的基因改變。大猩猩和人類確實在600萬至800萬年前擁有同一個祖先，但是自那以后很多事情都發生了變化。
Modern chimps evolved into a separate (though close) branch of the ape family tree.
現代大猩猩進化成了猿猴大家族的一個獨立（盡管關系很近的）分支。
MYTH: Lemmings jump off cliffs in mass suicides.
誤解四：旅鼠會集體跳崖自殺。
Lemmings do not commit mass suicide.
旅鼠并不會集體自殺。
During their migrations, or if they wander into an area they are unfamiliar with, they sometimes do fall off cliffs.
在遷徙過程中，如果旅鼠走到了一塊不熟悉的地方，它們有時確實會跌下懸崖。
No one knows exactly when the myth started, but a 1958 Disney video called White Wilderness, which won an Oscar for best documentary feature, has emerged over the years as the likeliest suspect.
沒人知道這個誤解是從哪里開始的，但是曾獲得奧斯卡獎的1958年迪士尼紀錄片《白色荒野》極有可能是這些年來這種誤解的起源。
MYTH: Bats are blind.
誤解五：蝙蝠是瞎子。
Being "blind as a bat" means not being blind at all.
“和蝙蝠一樣瞎”的意思是一點也不瞎。
While many use echolocation to navigate, all of them can see.
盡管很多蝙蝠用回聲定位能力來導航，但所有的蝙蝠都能看得見。
MYTH: Ostriches hide by putting their heads in the sand.
誤解六：鴕鳥想躲起來就把頭埋在沙子里。
Ostriches do not stick their heads in the sand when threatened. In fact, they don't bury their heads at all.
鴕鳥在受到威脅的時候不會把頭埋在沙子里。事實上，它們根本就不會把頭埋起來。
When threatened, ostriches sometimes flop on the ground and play dead.
在受到威脅時，鴕鳥有時會倒在地上裝死。
MYTH: People get warts from frogs and toads.
誤解七：人們碰到青蛙和蟾蜍會長疣子。
Frogs or toads won't give you warts, but shaking hands with someone who has warts can.
青蛙或蟾蜍不會讓你長疣子，但是和長疣的人握手會讓你長疣子。
The human papillomavirus is what gives people warts, and it is unique to humans.
讓人長疣子的是乳頭瘤病毒，這也是人類獨有的。
MYTH: Sharks can smell a drop of blood from miles away.
誤解八：鯊魚在幾英里外可以聞到一滴血的氣味。
This one is a big exaggeration. Jaws is not coming for you from across the ocean if you bleed in the water.
這個就太夸張了。如果你在海里流血，鯊魚不會從海的那一頭游過來吃你。
Shark have a highly enlarged brain region for smelling odours, allowing some of the fish to detect as little as 1 part blood per 10 billion parts water – roughly a drop in an Olympic-size swimming pool.
鯊魚大腦中有一塊特別大的區域和聞氣味有關，這讓一些鯊魚能夠覺察到100億份水中的一份血——大約相當于奧運會游泳池中的一滴血。
But the ocean is much, much, much bigger and it takes a while for odor molecules to drift. On a very good day when the currents are favourable, a shark can smell its prey from a few football fields away – not miles.
但是海洋比游泳池要大的多得多，而且氣味分子要傳過去也需要一段時間。如果天氣好，洋流方向又有利的話，鯊魚可以聞到幾個足球場面積以外的獵物——但不是幾英里。
MYTH: Giraffes sleep for only 30 minutes a day.
誤解九：長頸鹿每天只睡30分鐘。
Giraffes have fairly normal sleeping patterns, as far as diurnal animals go.
在白天活動的動物當中，長頸鹿的睡眠模式很正常。
To debunk this one, researchers closely monitored a herd of five adult and three young giraffes for 152 days, counting all of their naps and deep sleeps. The animals typically slept overnight and napped in the afternoon (sound familiar?).
為了破除這個誤解，研究人員在152天的時間里密切監視了五頭成年長頸鹿和三頭幼年長頸鹿，計算了它們打盹和深度睡眠的時間。長頸鹿通常在晚上睡覺，在下午小睡。（聽上去是不是很熟悉？）
In total, each giraffe slept about 4.6 hours every day.
總體而言，每頭長頸鹿每天大約睡4.6個小時。
MYTH: There are bugs in your strawberry Frappuccino.
誤解十：你的草莓星冰樂里有小蟲子。
This one used to be true – but not anymore.
以前是這樣的，但現在不是了。
Before April 2024, Starbucks' strawberry Frappuccino contained a dye made from the ground-up bodies of thousands of tiny insects, called cochineal bugs or Dactylopius coccus.
在2024年4月之前，星巴克的草莓星冰樂里含有一種用數千條小蟲子身體碾碎做成的染料，這種蟲子叫胭脂蟲。
Farmers in South and Central America make a living harvesting (and pulverising) the bugs that go into the dye. Their crushed bodies produce a deep red ink that is used as a natural food colouring, which was called "cochineal red" but is now called "carmine colour."
美洲南部和中部的農民以抓捕和碾碎胭脂蟲做染料為生。胭脂蟲磨碎的身體會產生一種深紅色的染料，用來做天然的食品著色劑，這種紅色過去叫“胭脂蟲紅”，不過現在叫洋紅色。
Starbucks stopped using carmine colour in their strawberry Frappuccinos in 2024. But the dye is still used in thousands of other food products – from Nerds candies to grapefruit juice. Not to mention cosmetics, like lovely shades of red lipstick.
2024年星巴克停止在草莓星冰樂里放胭脂蟲染色劑。但是這種染料仍然用在數千種其他食品中——從Nerds糖果到葡萄汁。更別提化妝品了，比如各種美麗色調的口紅。
MYTH: Sharks don't get cancer.
誤解十一：鯊魚不會得癌癥。
Back in 2024, researchers reported a huge tumour growing out of the mouth of a great white shark, and another on the head of a bronze whaler shark.
2024年，研究人員曾報告稱在一頭大白鯊的口中發現一顆巨大的腫瘤，并在另一頭短尾真鯊的頭上也發現了一顆腫瘤。
And those aren't the only cases of shark cancers: Other scientists have reported tumours in dozens of different shark species.
而且，這并不是鯊魚得癌癥的特例：其他科學家也報告過幾十種不同鯊魚出現的腫瘤。
The myth that sharks don't get cancer was reportedly created by William Lane to sell shark cartilage as a cancer treatment.
認為鯊魚不會得癌癥的誤解據說是威廉?萊恩制造的，他試圖將鯊魚軟骨作為抗癌食物售賣。
MYTH: Goldfish can't remember anything for longer than a second.
誤解十二：金魚對任何事情的記憶都不超過一秒。
Goldfish actually have pretty good memories.
金魚其實記憶力相當好。
They can remember things for months, not seconds like many people say.
它們對事物的記憶力可長達數月，而不像許多人所說的只有數秒。
MYTH: Humans got HIV because someone had sex with a monkey.
誤解十三：人類得艾滋病是因為有人和猴子發生性關系。
The human immunodeficiency virus, or HIV, almost certainly didn't jump to humans through human-monkey sex.
人體免疫缺損病毒，即艾滋病毒，基本可以肯定不是通過人和猴子的性交傳播給人類的。
Based on the virus' genetic similarity to a strain of simian immunodeficiency virus, or SIV, that infects chimpanzees, most experts think the virus jumped to humans through hunting primates for bush-meat food.
基于艾滋病毒與黑猩猩之間傳播的一種猿猴免疫缺損病毒的基因相似性，多數專家認為該病毒是通過獵殺靈長類動物以獲取野味食物而傳播給人類的。
This interaction may have led to blood-to-blood contact – perhaps through an open cut on the hunter – and the transfer of a new strain that could silently infect people.
在捕獵過程中可能會有血液接觸——也許是通過獵人身上的一道傷口——從而導致人類不知不覺地傳染上了這種新疾病。
MYTH: Any shark that stops swimming will suffocate and die.
誤解十四：停止游泳的鯊魚都會窒息而死。
You often hear sharks can breathe only when swimming pushes water over their gills.
你經常聽說鯊魚只有在游泳時才能呼吸，因為游起來時水才能從魚鰓流出。
That's true of a lot of sharks, but many others – like bottom-dwelling nurse sharks – can pump oxygen-rich water over their gills without swimming.
很多鯊魚都是如此，但也有很多其他鯊魚——比如住在海底的護士鯊——就算不游泳，富含氧氣的水也可以從魚鰓流出。
All sharks lack swim bladders, however, so if they stop swimming they will sink to the bottom. Luckily a shark's body is incompressible and rapid descents or ascents don't harm them.
但是，所有的鯊魚都沒有魚鰾，所以如果不游泳的話他們就會沉到海底。幸運的是，鯊魚的身體不會被壓縮，迅速的沉降和上浮都不會傷害到它們。
