Isopoda

Isopoda Temporal range: Latest Carboniferous to present 300–0 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Eurydice pulchra, a carnivorous isopod found on sandy shores
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Malacostraca
Superorder:	Peracarida
Order:	Isopoda Latreille, 1817 [1]
Suborders
Asellota Calabozoida Cymothoida Limnoriidea Microcerberidea Oniscidea Phoratopidea Phreatoicidea Sphaeromatidea Tainisopidea Valvifera

Isopoda is an order of crustaceans. Members of this group are called isopods and include both aquatic species, and terrestrial species such as woodlice. All have rigid, segmented exoskeletons, two pairs of antennae, seven pairs of jointed limbs on the thorax, and five pairs of branching appendages on the abdomen that are used in respiration. Females brood their young in a pouch under their thorax called the marsupium.

Isopods have various feeding methods: some eat dead or decaying plant and animal matter, others are grazers or filter feeders, a few are predators, and some are internal or external parasites, mostly of fish. Aquatic species mostly live on the seabed or the bottom of freshwater bodies of water, but some taxa can swim for short distance. Terrestrial forms move around by crawling and tend to be found in cool, moist places. Some species are able to roll themselves into a ball as a defense mechanism or to conserve moisture like species in the family Armadillididae, the pillbugs.

There are over 10,000 identified species of isopod worldwide, with around 4,500 species found in marine environments, mostly on the seabed, 500 species in fresh water, and another 5,000 species on land. The order is divided into eleven suborders. The fossil record of isopods dates back to the Carboniferous period (in the Pennsylvanian epoch), at least 300 million years ago, when isopods lived in shallow seas. The name Isopoda is derived from the Greek roots iso- (from ἴσος ísos, meaning "equal") and -pod (from ποδ-, the stem of πούς poús, meaning "foot").^[2][3]