Mantis Shrimp (Odontodactylus scyllarus)

CrustaceanReefPredator

Overview

Mantis shrimp (order Stomatopoda) are among the most extraordinary animals in the sea — colourful marine crustaceans that are not true shrimp, but a distinct ancient group of predators. The peacock mantis shrimp (Odontodactylus scyllarus), shown here, is a rainbow-hued reef species and a famous example. Two features make mantis shrimp legendary: an astonishingly fast and powerful strike, and a pair of eyes thought to be among the most complex of any animal.

Depending on the species, the striking appendages are either spears for impaling soft prey (“spearers”) or club-like hammers for smashing hard shells (“smashers”) — and the smashers punch with truly remarkable force.

Note: there are many mantis shrimp species; details here use the peacock mantis shrimp as a reference. Treat general statements as approximate and verify against authoritative sources.

Habitat & Range

Mantis shrimp live in warm and temperate seas around the world, mostly in shallow tropical and subtropical waters on coral reefs, rubble, and seabeds. Many live in burrows or crevices, which they defend and use as a base from which to ambush or chase prey. The peacock mantis shrimp is an Indo-Pacific reef-dweller.

Diet

Mantis shrimp are carnivores. “Smashers” like the peacock mantis shrimp use their hammer-like clubs to crack open hard-shelled prey — crabs, snails, clams, and other molluscs and crustaceans — while “spearers” impale soft prey such as fish and worms with spiny, harpoon-like appendages. Their powerful weapons let them tackle prey that many predators cannot.

Behavior

The mantis shrimp's strike is one of the fastest movements in the animal kingdom: a smasher's club accelerates so rapidly that it can shatter shells, and the strike is so fast it briefly boils the surrounding water, creating tiny collapsing bubbles (cavitation) that add a second, shockwave-like blow. Equally remarkable are the eyes: mounted on mobile stalks, they have many types of colour receptors and can detect polarised light, giving mantis shrimp a way of seeing the world quite unlike our own. Many species are solitary and fiercely territorial.

Human Interaction & Conservation

Mantis shrimp are admired by divers and aquarists for their colour and behaviour, though large ones are handled with care — a smasher can crack aquarium glass and deliver a painful blow. They are part of healthy reef ecosystems as predators of shelled invertebrates. Most are not of major conservation concern, though reef degradation affects them. Consult authoritative sources for details.

More photos of the mantis shrimp