螳螂虾在空中挥舞着有力的拳头

螳螂虾在空中挥舞着有力的拳头

Mantis shrimps are famous for two things: perhaps the most extraordinary visual capacity of any animal, and the most powerful punch in the animal kingdom. Now a new twist has been placed on the second, with the discovery that mantis shrimps can only perform their extraordinary jabs underwater. In air, they limit themselves, probably lest they injure themselves.

螳螂虾以两样东西而闻名:也许是所有动物中最非凡的视觉能力，以及动物王国中最有力的拳头。现在，人们发现螳螂虾只能在水下进行特别的刺击。在空中，它们限制自己，也许是为了避免伤害自己。

Mantis shrimps kill prey and fight off enemies using limbs known as maxillipeds that punch or spear targets. The speed of movement of these limbs is the fastest ever recorded for an animal. One mantis shrimp reportedly shattered the bulletproof glass of the aquarium in which he was housed.

螳螂虾会杀死猎物，用上肢攻击敌人。这些肢体的运动速度是有记录以来动物最快的。据报道，一只螳螂虾打碎了他所在水族馆的防弹玻璃。

The mantis shrimp punch is even more extraordinary when you consider it is conducted underwater, where viscous drag slows movements down. Dr Kathryn Feller of the University of Minnesota wondered how fast mantis shrimps would manage if this restriction was removed. Because scientists get to be cool sometimes she tested it by restraining seven shrimps of the species Squilla mantis in place and tickling their abdomens to induce punching. Because science can also be dangerous, Feller reported: “I have a pretty epic photo of my bleeding hand over a white sink when one stabbed me during this process,” in a background piece.

当你考虑到螳螂捕虾是在水下进行的时候，那就更不寻常了，因为水下的粘性阻力会减慢运动速度。明尼苏达大学的博士Kathryn Feller想知道如果取消了这一限制，螳螂虾能跑多快。因为科学家们有时会觉得很酷，所以她测试了这个方法:在适当的地方抑制七只这种虾的螳螂，并在它们的腹部挠痒痒，让它们出拳。因为科学也可能是危险的，Feller在一篇背景文章中写道:“我有一张相当壮观的照片，我流血的手在一个白色的水槽上，在这个过程中被人刺伤了。”

The aquarium's water level was adjusted so the punches were thrown sometimes underwater and sometimes in air, but the subjects' gills were always safely beneath the waterline.

水族馆的水位是可以调整的，所以拳头有时扔在水下，有时扔在空中，但实验对象的鳃总是安全的在水线以下。

To her surprise, Feller found instead of relishing their new-found freedom, these tiny pugilists instead pulled their punches, moving at not much more than half the speed and unleashing a third the kinetic energy. On investigation, she concluded the shrimps deliberately limit their strike force in air.

令她惊讶的是，Feller发现这些小螳螂虾们非但没有享受到它们新获得的自由，反而还在挥拳猛击，它们的速度不到原来的一半，释放出了三分之一的动能。经过调查，她得出结论，这些虾是故意限制它们在空中的攻击力量。

Stephen Luntz

Mantis shrimps achieve their remarkable punching power not with muscles, but with what are known as “spring-actuated systems”. Locusts and fleas use something very similar to leap into the air. Like an archer storing energy in a bow to be released very suddenly, the mantis shrimp's maxillipeds are latched into place before it uses its muscles to load energy in a spring, which then releases it far more rapidly than it was stored.

螳螂虾出拳的力量不是靠肌肉，而是靠所谓的“弹簧驱动系统”。蝗虫和跳蚤用一种非常类似的东西来跳跃到空中。就像弓箭手把能量储存在弓里，然后突然释放出来一样，螳螂虾的上颌骨在它用肌肉在弹簧中加载能量之前就被锁住了，然后弹簧释放能量的速度比储存的要快得多。

Given that more powerful punches underwater don't seem to tire them out much, Feller thinks this modulation must reflect a risk that, if not dissipated by the water's drag, the mighty punch could harm the puncher as well as the target, perhaps through lack of a suitable braking mechanism. Locusts have a shock-absorbing material in their legs to prevent damage from excess kinetic energy; mantis shrimps are not known to have anything equivalent, so may have worked out long ago not to push too hard in air. “The animals don't give it the full pow so they don't blow out their joint,” Feller speculated.

考虑到在水下更有力的击打似乎不会使它们疲劳，Feller认为这种调节一定反映了这样一种风险，如果不被水的阻力驱散，强大的击打可能会伤害击打者和目标，也许是由于缺乏合适的刹车机制。蝗虫的腿上有一种减震材料，可以防止动能过剩造成的伤害;人们不知道螳螂虾是否也有类似的东西，所以可能很久以前就知道不要在空气中用力过猛。Feller推测说:“动物们不会把整块骨头都掏出来，这样就不会伤害关节。”

Feller notes in the Journal of Experimental Biology: “S. mantis strikes in air have a similar mass and performance to latch-mediated spring-actuated jumps in locusts, suggesting a potential threshold for the energetics of a 1-2 gram limb rotating in air.” In other words, mantis shrimps may be operating at the limits of what is biologically possible.

Feller在《实验生物学杂志》上写道:“S。螳螂在空中的攻击在质量和性能上与蝗虫的闭锁弹簧驱动的跳跃相似，这表明一个1-2克的肢体在空气中旋转的潜在阈值。换句话说，螳螂虾可能已经达到了生物学极限。

One disadvantage of spring-actuated systems is they happen so fast no animal's brains can stop, or even alter the movement, once it is engaged.

弹簧驱动系统的一个缺点是，它们发生得太快了，动物的大脑一旦被控制，就无法停止，甚至改变运动。