Crustaceans

Peacock Mantis Shrimp

Odontodactylus scyllarus · Crustacean, order Stomatopoda (mantis shrimps), a smasher-type stomatopod; not a true shrimp

The peacock mantis shrimp carries the fastest punch a diver will ever share water with: spring-loaded raptorial clubs that accelerate through water hard enough to crack crab armor, with a collapsing cavitation bubble striking a second time behind the blow. Aquarists call them thumb splitters; divers mostly meet flashes of emerald, scarlet, and turquoise scuttling between rubble burrows. The eyes may be stranger than the weapons: mounted on independent stalks, packed with more photoreceptor classes than almost any animal studied, and sensitive to polarized light, they track a passing diver like gun turrets. Females brood egg masses in the burrow, and monogamous pairs hold the same territory for years at some sites. Watch from a respectful half meter, and keep fingers, pointers, and dome ports away from the front door. The clubs answer for the shrimp.