会飞的鱿鱼 Flying Squid

会飞的鱿鱼 Flying Squid
In the spring of 1947, six Scandinavian explorers noticed a strange phenomenon while crossing the Pacific Ocean.
1947年春，当六位斯堪的纳维亚探险者穿越太平洋时，他们发现了一个奇异的现象。
Somehow, small squid known to live deep beneath the waves kept appearing on the roof of their boat.
莫名其妙地，原本应生活在深海波涛之下的小乌贼接连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.
船员们一头雾水——直到他们目睹了乌贼在海面上方约50米飞翔的奇观。
On land, people could barely believe the explorers.
在陆地上，人们简直难以置信这些探险者的故事。
It seemed impossible that sea creatures without wings or bones could fly at all, let alone travel half the length of a football field.
海洋生物既无翅膀也无骨骼，它们能够飞行简直让人难以置信，更别说飞过半个足球场那么远的距离了。
But over the next several decades, more reports began to surface.
但在随后的几十年间，更多的报告逐渐浮出水面。
Sailors described airborne squid keeping pace with motor boats.
水手们描述，空中飞行的鱿鱼能与摩托艇保持同样的速度。
Researchers reported captive squid escaping their tanks overnight.
研究人员报道，一些被抓住的乌贼能在夜间逃出水箱。
And as cameras became widespread, seafarers finally began capturing proof of these high-flying cephalopods.
随着摄像头变得普遍，海员们终于能够记录下这些高飞的头足类动物的真凭实据。
But how and why do these marine creatures take to the sky?
但这些海洋生物为何以及如何飞上天空呢？
While only a few squid species have been recorded taking flight, most squid are alike in the way they traverse the ocean.
尽管只有少数乌贼物种被观察到能够飞行，但在穿越海洋的方式上，大部分乌贼是相似的。
The outside of a squid's body is a massive tube of muscle called the mantle.
乌贼的外体是一个称作外套膜的巨大肌肉管。
Water enters that tube through small openings around the squid's head.
水从乌贼头部周围的小孔进入这个管状结构。
Then, muscles clamp these openings shut, and the squid forcefully pumps the water through the base of their body.
接着，肌肉紧闭这些孔口，乌贼强力地把水从身体底部泵出。
In practice, this makes the mantle a miniature jetpack, propelling squid through the water at 10 kilometers per hour.
实践中，这相当于给乌贼装上了一个微型喷气背包，让它以每小时10公里的速度在水中前进。
This process is also how squid breathe.
这一过程同样是乌贼进行呼吸的方式。
Squid gills rest inside the mantle, and siphon oxygen from the water being pushed past them.
乌贼的鳃藏于外套膜之内，利用流过的水摄取氧气。
With gills full of air and a mantle full of water, squid can outpace predators and pursue their prey.
鳃充满空气、外套膜充满水，乌贼得以超出捕食者的速度追逐其猎物。
Or, in the case of some species, they can smash through the ocean's surface, and attempt an epic flight.
或者，对于某些物种而言，它们能够冲破海面，展开一场壮观的飞跃。
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.
在没有水阻的情况下，乌贼加速的速度可以与汽车在一秒多的时间里从零加速到每小时100公里相媲美。
At speeds of 40 kilometers per hour, squid quickly generate aerodynamic lift.
当速度达到每小时40公里时，乌贼能迅速产生空气动力升力。
But to stay in the air they'll need something like wings.
但若要维持空中飞行，它们就得需要像翅膀这样的器官。
Fortunately, our soaring cephalopod has a plan.
幸好，我们的飞行头足类动物已经想好了对策。
Squid tentacles are "muscular hydrostats," meaning the tissue can be held firm by muscle tension.
鱿鱼的触须属于“肌肉水压结构”，这意味着其组织可以依靠肌肉的张力来维持其稳定性。
Splaying its tentacles in a rigid formation, the squid transforms them into flexible wing-like structures that stabilise its flight.
鱿鱼将触须伸展开，形成一种刚性阵列，并把它们变形成可以稳定飞行的柔性翼状结构。
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，两个平时用来慢游的鳍发挥出新的作用，变成了第二对翅膀。
And by folding these fins down, a squid can streamline itself and dip back into the ocean.
通过折叠这些鳍，鱿鱼能够变得更加流线型，然后再次潜入海中。
There have been too few observations to establish what a squid's typical flight trajectory looks like.
目前的观察不足以确立鱿鱼典型飞行轨迹的样貌。
Based on their flying speed, a 10 centimeter squid could hypothetically launch itself six meters above the water.
根据飞行速度，一只10厘米的鱿鱼理论上能够跃出水面，飞行至六米的高度。
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，飞鱿通常倾向于低空滑翔，紧贴水面。
This trajectory allows squid to cover the most horizontal distance possible over a typical several second flight.
这种轨迹使得鱿鱼能够在几秒钟的飞行时间里尽可能地覆盖最大的水平距离。
It also makes it easy to dive back into the water for more fuel— or to make a quick escape from predatory birds.
这样一来，它们便能轻松潜回水中补充能量，或者迅速躲避捕食性鸟类的追捕。
But why do squids fly at all?
但鱿鱼为何要飞行呢？
Leading theories suggest that flight is an escape behaviour, as flying squid generally seem to be fleeing a nearby predator or ship.
主流理论认为，飞行是鱿鱼的一种逃脱行为，它们通常在逃避附近的捕食者或是船只。
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.
其他研究者则认为，它们之所以飞行，可能是作为一种节能的迁移策略，因为通过空中快速移动比穿越水域需要的能量更少。
However, it's also possible that learning to fly may be a vital part of surviving adolescence.
然而，飞行能力的习得也可能是青少年生存阶段的一个关键因素。
Young, smaller squid can potentially fly faster and farther than their larger relatives.
相较于体型较大的同类，年轻和体积较小的鱿鱼有潜力飞得更远、更快。
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，鉴于成年鱿鱼倾向于吃掉幼小的同类，能够在海浪之上飞翔有助于这些年轻鱿鱼存活下来，争取到更多飞翔的机会。