7.Catfish Have About 100,000 Taste Buds
7.鲶鱼约有10万个味蕾
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.
人类的味蕾一般有2000－8000个，全部集中在嘴里那一小块灵活的肌肉上。然而，鲶鱼有近100000个单独的味蕾——遍布全身。某种程度而言，一条鲶鱼就是一条游动的舌头。每个味蕾约有50纳米（10亿分之50米，或说10亿分之164英尺）宽，而且鱼越大，味蕾越多。比较大的鱼全身能有175000多个味蕾。
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.
为什么动物——尤其是住在昏暗池底的淤泥里的动物——需要这么强大的嗅觉功能？它们用来捕食。越往深处，视觉越受到限制，所以对像鲶鱼这类住在池底的居民而言，视觉没那么有用。鲶鱼能用味蕾"尝到"几米之外的猎物，就像狼捕捉到一股气味。它们全身这么多味蕾，实际上是运用三角定位的方法，凭借身体各个部位嗅到气味的强度不同，确定猎物的位置。大部分味蕾聚集在鲶鱼身体前部，所以只要找对了方向，它们就能直接抓住猎物。
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.
鲶鱼仍然会使用眼睛，但是研究人员发现，味蕾比视觉对捕猎更重要。移除鲶鱼的眼睛之后，鲶鱼仍能找到食物。但是移除了味蕾，它们就真的瞎了。
6.Dolphins Can See Through Animals
6.海豚能看透动物
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，海豚在水中使用声呐进行导航、捕食、交流等几乎所有的活动。海豚的声呐在人们看来就是回声定位，其中包括高频声音——通过将空气压进喷水孔附近的身体组织网而发声。它们颚下有一个由脂肪组织构成的囊，用来收集反射回来的声波并送至海豚内耳，然后这些信息再被传至大脑，构成"声学全息图像"，即呈现在海豚前面的海洋的画面。
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.
回声定位发射的高频声音——40－130赫兹——不适合在水中进行长距离传输，但是波长更短却很适合穿透柔软的物体。换句话说，声波会透过其他鱼类和海豚柔软的身体，只有碰到诸如骨头和软骨等坚硬的表面才会反射回来。也就是说，声波起着X射线成像的功能，让海豚能看见其他动物的内部结构。根据海豚的行为（尤其是宽吻海豚的行为），人们认为海豚能看见鲨鱼的胃里是否装满了食物，或者雌海豚是否怀孕。人们还观察到海豚沿着海床发出喀哒声，搜寻深藏在沙子下面深达1米（3英尺）的鱼类。
5.膨胀鲨
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.
大部分鲨鱼能将进攻者吓跑，只因为它们是鲨鱼。但是，它们仍然有天敌，而且体型越小，敌人越多。膨胀鲨是小型鲨鱼之一，只能长到1米（3英尺）长，大概与小型多伯曼氏短尾狗差不多大。膨胀鲨在海底觅食，喜欢伏击螃蟹和没有防备的乌贼，而不是冒着危险刺激地追赶普通的鱼儿。充满冒险的一天意味着从龙虾陷阱里偷吃龙虾。膨胀鲨为防御措施费尽心机，是化装高手：受到威胁时，它们会将海水吸入贴在腹部四周的囊中，身体就会膨胀为正常大小的两倍。
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.
但是它们还有更古怪的行为——它们将身体弯成新月形，用嘴衔住尾巴，把自己变成一个巨大的膨胀的环。结果它们就变得……不容易被吃掉了。它们通常潜伏在石头缝隙中，所以膨胀是实际上让它们卡在藏身地。即使被一条鱼咬住了，它们顶多损失一块肉而不会被拉出去。人们常常视它们为最神奇的鲨鱼。
4.Pompeii Worms Have A Living Shield
4.庞贝虫有一块活盾牌
"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.
"地球上温度最高，但又是最难研究的"就是如何描述庞贝虫，即"Alvinella pompejana"。不仅因为这些虫住在海下2500米（8000英尺）的火山口里，四周水温高达80°C（176°F），还因为它们离开水面就会死亡，这很难办。长期以来，人们认为庞贝虫是地球上最能耐热的动物。它们能长到13厘米（5英寸）长，住在"冒黑烟的"斜边上的隧道里——东太平洋高地地面已经排完烟雾的火山口。
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，它们要出名还有一些问题要解决。研究人员用高压仓将一些虫子带进了实验室，发现它们暴露在50°C（122°F）的水里10分钟就死了，它们的组织硬得像煮熟的鸡蛋——它们被煮了。但事实是，庞贝虫就活在这样高温的海水里，所以他们进行了更仔细的研究，结果发现虫子体外一般覆盖着一层细菌。它们便有了一层活的铠甲，像消防员的毯子那样，吸收了热水的一部分热量。作为回报，虫子产生一层粘液养活细菌——完美的共生。
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