antis shrimp are predatory marine crustaceans
that live in the shallow waters of tropical and subtropical seas.
They make up a small but diverse group of strictly marine crustaceans
that are only distantly related to the more common shrimps and crabs.
The stomatopod lineage diverged from other crustaceans 400 million
years ago, and today about 350 species are known. Stomatopods are
characterized by a pair of large folded limbs that they use to capture
their prey--thus the Latin name "mouth foot." These paired
limbs are called raptorial appendages, and are analogous to the
forelimbs of a praying mantis, which led to the common name of mantis
shrimp. Their strike with this raptorial appendage is completed
in three to four milliseconds--several times faster than the praying
mantis, and comparable in speed to a twenty-four-caliber bullet.
Mantis shrimp have evolved an elaborate visual system that allows
them to flourish in the well-lit tropical waters they inhabit. With
their complex eyes, these crustaceans have the ability to see polarized
and ultraviolet light; many species have three times as many visual
pigments as humans.
Mantis shrimp are also capable of monocular stereopsis, or the
ability to percieve depth with a single eye. This can be very useful,
allowing the animal to perform multiple tasks (observing prey movement
with one eye, and judging distance with the other) or function successfully
when one eye is lost in combat.
--Pamela Cox Jutte
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