为什么锤头鲨的头如此搞笑?

为什么锤头鲨的头如此搞笑?

There are more than 360 species of sharks: Big ones, wee ones, aggressive ones, sweet ones, sleek ones, and …really awkward-looking ones — specifically, the nine species of hammerhead sharks. The scientific genus name of hammerhead sharks is Sphyma, which comes from the Greek word for hammer. And hammer it does resemble. Unlike the aerodynamic streamlined heads of most sharks, the hammerhead has a big clunky head that appears to be at odds with the rest of its body, like a showgirl with an extra-cumbersome headpiece.

世界上有360多种鲨鱼:大的，小的，好斗的，可爱的，圆滑的和…长得真的很尴尬的鲨鱼-特别是九种锤头鲨。锤头鲨的科学属名是Sphyma，它来源于希腊语中的锤子，跟锤子特别像。与大多数鲨鱼的流线型头部不同，锤头鲨有一个笨重的大脑袋，看起来和它身体的其他部分不一致，就像一个戴着非常笨重的头饰的卖艺女郎。

Although sharks are fish (rather than marine mammals), they give birth to live young rather than hatching eggs. If you’re wondering about the physical logistics of the hammerhead in this scenario, take solace in knowing that when the pups are born, their heads are round. It’s not until they reach maturity that the hammer-shaped head is in full swing.

虽然鲨鱼是鱼(而不是海洋哺乳动物)，但它们生的是活的幼崽，而不是孵化的卵。如果你想知道在这种情况下锤头鲨的身体结构，那么请放心，当幼崽出生时，它们的头是圆的。直到它们发育成熟，锤状的头部才会完全展开。

The question is: Why, in all of her infinite wisdom, would Mother Nature lead an animal down such a curious evolutionary path?

问题是：为什么大自然会用她无限的智慧引导这种动物走上一条如此奇特的进化之路?

Well, these are sharks we’re talking about, so it’s little surprise that the answer has to do with finding prey. Hammerhead sharks are voracious predators and their mallet-shaped heads boost their ability to find that which they like to eat. The wide expanse of head allows for a broader spread of highly specialized sensory organs that they use to find food. And beyond smell and vision, these sensory organs are rather high-tech. The "ampullae of Lorenzini" group of organs allows the stealth hunters to detect electrical fields created by prey. The hammerhead's increased ampullae sensitivity helps it track down its favorite meal, stingrays, which are usually hidden under the sand.

我们说的是鲨鱼，所以答案与寻找猎物有关也就不足为奇了。锤头鲨是一种贪婪的食肉动物，它们锤状的头部可以提高它们找到自己喜欢吃的东西的能力。头部的宽阔使得它们用来寻找食物的高度专门化的感觉器官可以更广泛地分布。除了嗅觉和视觉，这些感官还相当高科技。“洛伦兹尼的壶腹”器官群可以让隐形猎人探测到猎物产生的电场。锤头鱼腹部的敏感度增加，有助于它找到自己最喜欢的食物——黄貂鱼，黄貂鱼通常藏在沙子下面。

In addition, that funny wide head allows for very special placement of the eyes which results in — as counterintuitive as it may seem — outstanding binocular vision. The position of the eyes also allows the sharks to see above and below them at all times. In the meantime, by moving their head sideways as they swim, they can observe much of what is behind them. All the better to help find those stingrays.

此外，有趣的宽头使得眼睛的位置非常特殊，这使它拥有出色的双目视觉，尽管看起来可能是反视觉的。眼睛的位置也让鲨鱼能够随时看到它上下的情况。与此同时，通过在游泳时将头侧向一边，它们可以观察到身后的大部分情况，能找到那些黄貂鱼就更好了。

And once they find dinner, hammerheads use that brute head to pin the stingray to the seafloor for the kill.

一旦它们找到了食物，锤头鲨就会用它那残忍的脑袋把黄貂鱼钉在海底进行捕杀。

The largest of the hammerhead species can grow to be up to 20 feet in length, although more commonly they are relatively small. They have few predators and are considered harmless to humans. For the stingrays, it’s another story.

最大的锤头鲨可以长到20英尺长，虽然它们通常都比较小。它们几乎没有天敌，而且对人类无害。对于黄貂鱼来说，则是另一回事。