How fast can a peacock mantis shrimp's striking appendage move?

A peacock mantis shrimp's striking appendage can move at about 23 metres per second. This extreme speed allows the animal to deliver one of the fastest movements known in the animal kingdom.

The peacock mantis shrimp is a smasher-type mantis shrimp. Its club-like appendages are held under tension by a springlike latch system and released rapidly. The movement is powered by stored elastic energy rather than by muscle contraction alone, which helps the appendage accelerate so quickly.

The strike can crack hard shells and may produce cavitation bubbles in the surrounding water. When those bubbles collapse, they create an additional shock effect, so prey can be damaged by more than the direct impact. The animal uses this weapon to break open crabs, snails, and other hard-bodied prey.

The figure is an approximate measured speed, not a universal constant for every strike. Different studies and species can produce different values, and the mantis shrimp's speed should not be confused with the speed of the collapsing cavitation bubble or the sound produced underwater.