The Mantis Shrimp Punch That Boils Water

If you put a peacock mantis shrimp in a regular glass aquarium, it will eventually shatter the walls and leave your living room flooded.

This crustacean doesn't just hit hard; it accelerates its front limbs at the same speed as a .22 caliber bullet. It moves from zero to 50 miles per hour in an underwater blink, delivering a blow with about 1,500 Newtons of force.

The physics behind the punch shouldn't actually work. To generate that much power, a biological muscle would have to be impossibly large. Instead, the shrimp uses a latch-and-spring mechanism located in its elbow, built from a saddle-shaped structure that acts like a composite bow.

It cocks its arm back, locks it in place, and stores massive amounts of elastic energy. When the latch releases, the arm snaps forward so fast that the surrounding water can’t move out of the way quick enough.

This create a vacuum. For a fraction of a second, the pressure of the water drops below its vapor point, causing the liquid to boil instantly. Tiny bubbles form and then immediately collapse in a process called cavitation.

When these bubbles implode, they release a secondary shockwave that hits the prey with nearly as much force as the limb itself. If the shrimp misses its target, the shockwave alone is usually enough to kill the crab or snail it was aiming at.

During this collapse, the interior of the bubble produces a flash of light and a burst of heat. For a microsecond, the temperature inside that tiny pocket of steam reaches several thousand degrees Kelvin—roughly the temperature of the surface of the sun.

The shrimp is effectively a living railgun. Its clubs are made of highly dense hydroxyapatite, layered in a spiraling pattern that prevents cracks from spreading. This allows the creature to strike thousands of times without his own arms shattering under the weight of his own physics.

While the shrimp is famous for its punch, its eyes are even weirder; they possess 16 color-receptive cones, whereas humans have only three, allowing the shrimp to see types of light and circular polarization that are invisible to every other animal on Earth.