Peacock Mantis Shrimp

• fisiologíaIt strikes with its front limbs so fast that it creates cavitation bubbles, whose collapse gives off a momentary flash of light and heat.
• Its eyes, mounted on independently mobile stalks, have between twelve and sixteen types of photoreceptor, against three in the human eye, and detect polarised and ultraviolet light.
• The collapse of the bubble delivers a second impact that reaches the prey even if the first blow misses.
• It has been known to break aquarium glass with a single strike.
• Its strike is one of the fastest movements in the animal kingdom: it accelerates the appendage to more than 20 metres per second, with an acceleration comparable to that of a .22 calibre bullet.
• And it lands two blows with a single strike. The speed is such that it causes cavitation: vapour bubbles form and collapse immediately, releasing a second impact in the form of a shock wave, heat and light. On average the cavitation forces amount to half those of the strike itself, and they can even exceed it.
• That means it can kill prey even if it narrowly misses, because the bubble arrives all the same.
• It breaks glass, which is why it is feared in the aquarium hobby: large specimens have cracked aquarium walls.
• The strike is not delivered directly by the muscles: it stores energy in an elastic structure of the limb, like a crossbow, and releases it all at once, which lets it exceed the power limit of muscle.
• Its eyes are among the most complex known: they have between 12 and 16 classes of photoreceptor, against three in humans, and they detect ultraviolet and polarised light. Each eye moves independently and has trinocular vision on its own.
• And a surprise: behavioural studies suggest that, despite those receptors, it does not tell colours apart any better than we do. Its system is thought not to compare signals as ours does, but to recognise colours directly — a faster, less precise kind of processing.

Skeleton type

Invertebrate - chitin exoskeleton (crustacean)

Habitat and environment

Burrows in sand and rubble bottoms on Indo-Pacific reefs

Sources consulted: Wikipedia (es): Odontodactylus scyllarus