為什么錘頭鯊的頭如此搞笑?
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多種鯊魚:大的,小的,好斗的,可愛的,圓滑的和…長得真的很尷尬的鯊魚-特別是九種錘頭鯊。錘頭鯊的科學屬名是Sphyma,它來源于希臘語中的錘子,跟錘子特別像。與大多數(shù)鯊魚的流線型頭部不同,錘頭鯊有一個笨重的大腦袋,看起來和它身體的其他部分不一致,就像一個戴著非常笨重的頭飾的賣藝女郎。
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.
雖然鯊魚是魚(而不是海洋哺乳動物),但它們生的是活的幼崽,而不是孵化的卵。如果你想知道在這種情況下錘頭鯊的身體結(jié)構(gòu),那么請放心,當幼崽出生時,它們的頭是圓的。直到它們發(fā)育成熟,錘狀的頭部才會完全展開。
The question is: Why, in all of her infinite wisdom, would Mother Nature lead an animal down such a curious evolutionary path?
問題是:為什么大自然會用她無限的智慧引導這種動物走上一條如此奇特的進化之路?
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.
我們說的是鯊魚,所以答案與尋找獵物有關(guān)也就不足為奇了。錘頭鯊是一種貪婪的食肉動物,它們錘狀的頭部可以提高它們找到自己喜歡吃的東西的能力。頭部的寬闊使得它們用來尋找食物的高度專門化的感覺器官可以更廣泛地分布。除了嗅覺和視覺,這些感官還相當高科技。“洛倫茲尼的壺腹”器官群可以讓隱形獵人探測到獵物產(chǎn)生的電場。錘頭魚腹部的敏感度增加,有助于它找到自己最喜歡的食物——黃貂魚,黃貂魚通常藏在沙子下面。
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,有趣的寬頭使得眼睛的位置非常特殊,這使它擁有出色的雙目視覺,盡管看起來可能是反視覺的。眼睛的位置也讓鯊魚能夠隨時看到它上下的情況。與此同時,通過在游泳時將頭側(cè)向一邊,它們可以觀察到身后的大部分情況,能找到那些黃貂魚就更好了。
And once they find dinner, hammerheads use that brute head to pin the stingray to the seafloor for the kill.
一旦它們找到了食物,錘頭鯊就會用它那殘忍的腦袋把黃貂魚釘在海底進行捕殺。
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.
最大的錘頭鯊可以長到20英尺長,雖然它們通常都比較小。它們幾乎沒有天敵,而且對人類無害。對于黃貂魚來說,則是另一回事。