Animals
How hard does a mantis shrimp punch?
The short answer
Fast enough to boil water. A 2004 Nature study clocked the peacock mantis shrimp's club at around 23 metres per second, accelerating like a bullet. The strike drops the water pressure so sharply that vapour bubbles form and violently collapse — so prey gets hit twice.
Sheila Patek's team filmed the strike properly for the first time in 2004, using high-speed cameras to catch something that finishes in under three milliseconds. The club is launched by a saddle-shaped spring in the exoskeleton, latched and released rather than driven by muscle directly — muscle alone is far too slow for this.
The speed is only half the story. Moving that fast, the club drops the pressure of the water ahead of it enough to make it vaporise. Those cavitation bubbles collapse an instant later, releasing a burst of heat, light and force.
Cavitation is the same process that pits the stainless steel of boat propellers. A snail shell stands no chance. The shrimp lands one blow and the water lands a second.
Sources
- Deadly strike mechanism of a mantis shrimpNature
- The Mantis Shrimp Has the World's Fastest PunchNational Geographic