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In the spring of 1947, six Scandinavian explorers noticed a strange phenomenon while crossing the Pacific Ocean.
1947年春，六名斯堪的纳维亚探险家在穿越太平洋时注意到了一个奇怪的现象。
Somehow, small squid known to live deep beneath the waves kept appearing on the roof of their boat.
不知道为什么，生活在海洋深处的小乌贼不断出现在他们的船顶上。
The crew was mystified -- until they saw the squids soaring above the sea for roughly 50 meters. On land, people could barely believe the explorers.
船员们很困惑--直到他们看到乌贼在海面上飞行了大约50米。在陆地上，几乎没有人相信探险家们。
It seemed impossible that sea creatures without wings or bones could fly at all, let alone travel half the length of a football field.
没有翅膀和骨头的海洋生物根本不可能飞行，更不用说飞跃半个足球场了。
But over the next several decades, more reports began to surface. Sailors described airborne squid keeping pace with motor boats.
但在接下来的几十年里，出现了更多的报道。水手们描述，空中的乌贼与摩托艇齐头并进。
Researchers reported captive squid escaping their tanks overnight.
研究人员报告，捕获的鱿鱼一夜之间逃离了他们的鱼缸。
And as cameras became widespread, seafarers finally began capturing proof of these high-flying cephalopods.
随着照相机的普及，海员们终于开始抓拍这些头足类动物飞行的证据。
But how and why do these marine creatures take to the sky?
但是这些海洋生物是如何做到，以及为什么要飞行呢？
While only a few squid species have been recorded taking flight, most squid are alike in the way they traverse the ocean.
虽然只有少数品种的乌贼被记录到飞行，但大多数乌贼穿越海洋的方式是相似的。
The outside of a squid's body is a massive tube of muscle called the mantle. Water enters that tube through small openings around the squid's head.
乌贼身体的外面是一根巨大的肌肉管，称为“地幔”。水通过乌贼头部周围的小开口进入肌肉管。
Then, muscles clamp these openings shut, and the squid forcefully pumps the water through the base of their body.
然后，肌肉将这些开口夹住，乌贼用力将水泵入身体底部。
In practice, this makes the mantle a miniature jetpack, propelling squid through the water at 10 kilometers per hour.
实际上，这使得“地幔”成为一个微型喷气背包，以10km/h的速度在水中推动乌贼前进。
This process is also how squid breathe. Squid gills rest inside the mantle, and siphon oxygen from the water being pushed past them.
这也是乌贼的呼吸方式。乌贼的鳃位于“地幔”内，从流经它们的水中吸取氧气。
With gills full of air and a mantle full of water, squid can outpace predators and pursue their prey.
凭借充满空气的鳃和充满水的地幔，乌贼可以甩开捕食者以及追捕猎物。
Or, in the case of some species, they can smash through the ocean's surface, and attempt an epic flight.
某些品种可以冲破海洋表面，并尝试进行史诗般的飞行。
Without the resistance of water, a squid's acceleration is the same as a car going from zero to 100 kilometers per hour in just over a second.
没有水的阻力，乌贼的加速度就像汽车一样，从0到100km/h只需要一秒多一点。
At speeds of 40 kilometers per hour, squid quickly generate aerodynamic lift.
乌贼以40km/h的速度迅速产生空气动力升力。
But to stay in the air they'll need something like wings. Fortunately, our soaring cephalopod has a plan.
但是为了留在空中，它们需要像翅膀这样的东西。幸运的是，我们会飞的头足类动物已经有了计划。
Squid tentacles are "muscular hydrostats," meaning the tissue can be held firm by muscle tension.
乌贼的触手是“肌肉凝水器”，这意味着组织能通过肌肉张力保持牢固。
Splaying its tentacles in a rigid formation, the squid transforms them into flexible wing-like structures that stabilise its flight.
乌贼以僵硬的形式张开触手，将它们变成灵活的翅膀状结构，稳定它的飞行。
At the opposite end of its body, two fins typically used for gentle swimming find new purpose as a second set of wings.
在它身体的另一端，通常用于轻微摆动的两个鳍找到了新的用途--作为第二对翅膀。
And by folding these fins down, a squid can streamline itself and dip back into the ocean.
通过将这些鳍向下折叠，乌贼可以使自己呈流线型潜回大海。
There have been too few observations to establish what a squid's typical flight trajectory looks like.
由于观测资料太少，无法确定乌贼的典型飞行轨迹的模样。
Based on their flying speed, a 10 centimeter squid could hypothetically launch itself six meters above the water.
根据它们的飞行速度，一条10厘米长的乌贼大概可以在离水面6米的地方飞行。
But from what scientists have seen, flying squid tend to glide low, keeping close to the surface.
但从科学家们的观察来看，乌贼往往会在靠近水面处滑翔。
This trajectory allows squid to cover the most horizontal distance possible over a typical several second flight.
该轨迹能让乌贼在几秒的飞行中越过尽可能多的水平距离。
It also makes it easy to dive back into the water for more fuel -- or to make a quick escape from predatory birds.
它还可以轻松地潜回水中获取更多能量--或者快速躲避掠食性鸟类。
But why do squids fly at all? Leading theories suggest that flight is an escape behaviour, as flying squid generally seem to be fleeing a nearby predator or ship.
但是乌贼为什么要飞呢？主流理论认为飞行是一种逃避行为，乌贼似乎经常是在逃离附近的捕食者或船只时飞行。
Other researchers think their flight may be an energy-saving migration strategy, because it takes less energy to move quickly through the air than through water.
其他研究人员认为，它们的飞行可能是一种节能迁移策略，因为在空气中快速移动比在水中需要更少的能量。
However, it's also possible that learning to fly may be a vital part of surviving adolescence.
然而，学习飞行也可能是度过成长期的重要组成部分。
Young, smaller squid can potentially fly faster and farther than their larger relatives.
年轻的、较小的乌贼可能比它们较大的亲戚飞得更快、更远。
And since adult squid tend to cannibalize juveniles, soaring above the surf can help ensure these young squid will live to fly another day.
而且由于成年乌贼往往会蚕食未成年乌贼，因此在海上飞行可以帮助这些年轻的乌贼活到可以自由飞翔的那一天。
