7.Catfish Have About 100,000 Taste Buds
7.鯰魚約有10萬個味蕾
Humans have somewhere between 2,000 and 8,000 taste buds, all concentrated on the little lump of flesh wiggling around your mouth. Catfish, on the other hand, have closer to 100,000 individual taste buds—all over their bodies. In a sense, a catfish is just a big swimming tongue. Each taste bud is about 50 nanometers (50 billionths of a meter, or 164 billionths of a foot) wide, and the bigger the fish is, the more taste buds it has. Larger fish can have more than 175,000 taste buds dotted across their body.
人類的味蕾一般有2000－8000個，全部集中在嘴里那一小塊靈活的肌肉上。然而，鯰魚有近100000個單獨的味蕾——遍布全身。某種程度而言，一條鯰魚就是一條游動的舌頭。每個味蕾約有50納米（10億分之50米，或說10億分之164英尺）寬，而且魚越大，味蕾越多。比較大的魚全身能有175000多個味蕾。
Why would an animal—especially one that lives in the mud at the bottom of murky ponds—need such a strong sense of taste? They use it to hunt. Visibility becomes more limited the deeper you go, so for a bottom dweller like the catfish, sight isn't always helpful. With their taste buds, catfish can "taste" prey meters away, like a wolf catching a scent. And with so many buds all over their body, they can essentially triangulate the prey's location based on how strongly the taste hits certain body parts. Most of the taste buds are clustered around the fore region of the catfish so it can home in on the prey once it's angled in the right direction.
為什么動物——尤其是住在昏暗池底的淤泥里的動物——需要這么強大的嗅覺功能？它們用來捕食。越往深處，視覺越受到限制，所以對像鯰魚這類住在池底的居民而言，視覺沒那么有用。鯰魚能用味蕾"嘗到"幾米之外的獵物，就像狼捕捉到一股氣味。它們全身這么多味蕾，實際上是運用三角定位的方法，憑借身體各個部位嗅到氣味的強度不同，確定獵物的位置。大部分味蕾聚集在鯰魚身體前部，所以只要找對了方向，它們就能直接抓住獵物。
Catfish still use their eyes, but researchers have found that the taste buds are more important for hunting than sight. Take away a catfish's eyes and it will still find food. Take away its taste buds, however, and it's essentially blind.
鯰魚仍然會使用眼睛，但是研究人員發現，味蕾比視覺對捕獵更重要。移除鯰魚的眼睛之后，鯰魚仍能找到食物。但是移除了味蕾，它們就真的瞎了。
6.Dolphins Can See Through Animals
6.海豚能看透動物
Dolphins, as everybody knows, use sonar to navigate through the water, hunt, communicate, and do just about everything. Known as echolocation, dolphin sonar involves high frequency bursts of sound created by forcing air through a network of tissues near their blowholes. A sac of fatty tissue below their jaws collects the rebounding sound waves and sends them through the dolphin's inner ear, where the information is passed on to the brain, creating an "acoustical holographic image," or a picture of the ocean in front of them.
人人都知道，海豚在水中使用聲吶進行導航、捕食、交流等幾乎所有的活動。海豚的聲吶在人們看來就是回聲定位，其中包括高頻聲音——通過將空氣壓進噴水孔附近的身體組織網而發聲。它們顎下有一個由脂肪組織構成的囊，用來收集反射回來的聲波并送至海豚內耳，然后這些信息再被傳至大腦，構成"聲學全息圖像"，即呈現在海豚前面的海洋的畫面。
The high frequency of the echolocation bursts—40–130 kHz—isn't well suited for traveling long distances through the water, but its shorter wavelength is perfect for penetrating soft objects. In other words, it travels through the soft bodies of other fish and dolphins and only reflects from the hard surfaces—bones and cartilage. In other (other) words, it functions like X-ray vision, allowing the dolphin to see into other animals. Based on dolphin behavior (especially in bottlenose dolphins), it's believed that dolphins can peer into shark stomachs to see when they're full, or to see when a female is pregnant. Dolphins have also been observed clicking along the seabed to spot hidden fish buried in up to 1 meter (3 ft) of sand.
回聲定位發射的高頻聲音——40－130赫茲——不適合在水中進行長距離傳輸，但是波長更短卻很適合穿透柔軟的物體。換句話說，聲波會透過其他魚類和海豚柔軟的身體，只有碰到諸如骨頭和軟骨等堅硬的表面才會反射回來。也就是說，聲波起著X射線成像的功能，讓海豚能看見其他動物的內部結構。根據海豚的行為（尤其是寬吻海豚的行為），人們認為海豚能看見鯊魚的胃里是否裝滿了食物，或者雌海豚是否懷孕。人們還觀察到海豚沿著海床發出喀噠聲，搜尋深藏在沙子下面深達1米（3英尺）的魚類。
5.膨脹鯊
Most sharks scare away predators simply by being, well, sharks. However, they do still have predators, and the smaller the shark species, the more predators there are. The swellshark is one of the smaller breeds, only growing to about 1 meter (3 ft) long, roughly the size of a small doberman. Swellsharks are bottom feeders, preferring to ambush crabs and unsuspecting cuttlefish over the risky thrill of chasing normal fish. An adventurous day means stealing lobsters from a lobster trap. And as far as defenses go, the swellshark is a master of disguise: When it's threatened, it sucks water into sacs that curve around its belly, swelling up to twice its normal size.
大部分鯊魚能將進攻者嚇跑，只因為它們是鯊魚。但是，它們仍然有天敵，而且體型越小，敵人越多。膨脹鯊是小型鯊魚之一，只能長到1米（3英尺）長，大概與小型多伯曼氏短尾狗差不多大。膨脹鯊在海底覓食，喜歡伏擊螃蟹和沒有防備的烏賊，而不是冒著危險刺激地追趕普通的魚兒。充滿冒險的一天意味著從龍蝦陷阱里偷吃龍蝦。膨脹鯊為防御措施費盡心機，是化裝高手：受到威脅時，它們會將海水吸入貼在腹部四周的囊中，身體就會膨脹為正常大小的兩倍。
But then it does something even weirder—it bends its body into a crescent, grabs its tail in its mouth, and turns itself into a big, inflated ring. The result is something that's just . . . hard to eat. And since swellsharks normally lurk in rocky crevices, the swelling effectively wedges them into their hiding spots. So even if a fish gets a hold of them, it won't be able to pull out anything larger than a mouthful. It's often referred to as the most awkward shark in the world.
但是它們還有更古怪的行為——它們將身體彎成新月形，用嘴銜住尾巴，把自己變成一個巨大的膨脹的環。結果它們就變得……不容易被吃掉了。它們通常潛伏在石頭縫隙中，所以膨脹是實際上讓它們卡在藏身地。即使被一條魚咬住了，它們頂多損失一塊肉而不會被拉出去。人們常常視它們為最神奇的鯊魚。
4.Pompeii Worms Have A Living Shield
4.龐貝蟲有一塊活盾牌
"The hottest animal on the planet, but the most difficult to study," is how the Pompeii worm, or Alvinella pompejana, has been described. Not only do these worms live 2,500 meters (8,000 ft) below the ocean's surface on volcanic vents that heat the surrounding water to 80 °C (176 °F), they also have an annoying tendency to die when brought to the surface. For a long time, Pompeii worms were believed to be the most heat-tolerant animals on the planet. They grow to about 13 centimeters (5 in) long and live in tubes attached directly to the sides of "black smokers," smoke-belching exhaust vents on the floor of the East Pacific Rise.
"地球上溫度最高，但又是最難研究的"就是如何描述龐貝蟲，即"Alvinella pompejana"。不僅因為這些蟲住在海下2500米（8000英尺）的火山口里，四周水溫高達80°C（176°F），還因為它們離開水面就會死亡，這很難辦。長期以來，人們認為龐貝蟲是地球上最能耐熱的動物。它們能長到13厘米（5英寸）長，住在"冒黑煙的"斜邊上的隧道里——東太平洋高地地面已經排完煙霧的火山口。
However, their claim to fame has been called into question. Using pressurized capsules, researchers managed to bring a few of the worms up to a lab and found that after 10 minutes of exposure to temperatures of 50 °C (122 °F), the worms died and their tissues hardened like a boiled egg—they were cooked. But the fact remained that Pompeii worms did indeed live in these temperatures, so they took a closer look and found that a layer of bacteria normally lived around the worms. They had a living shield that absorbed part of the heat from the scalding water like a fireman's blanket. In return, the worms were producing a mucous layer that fed the bacteria—a perfect symbiosis.
但是，它們要出名還有一些問題要解決。研究人員用高壓倉將一些蟲子帶進了實驗室，發現它們暴露在50°C（122°F）的水里10分鐘就死了，它們的組織硬得像煮熟的雞蛋——它們被煮了。但事實是，龐貝蟲就活在這樣高溫的海水里，所以他們進行了更仔細的研究，結果發現蟲子體外一般覆蓋著一層細菌。它們便有了一層活的鎧甲，像消防員的毯子那樣，吸收了熱水的一部分熱量。作為回報，蟲子產生一層粘液養活細菌——完美的共生。
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