Amphipoda is an order of malacostracan crustaceans with no carapace and generally with laterally compressed bodies. Amphipods range in size from 1 to 340 millimetres and are mostly detritivores or scavengers. There are more than 9,900 amphipod species so far described. They are mostly marine animals, but are found in almost all aquatic environments. Some 1,900 species live in fresh water, and the order also includes the terrestrial sandhoppers such as Talitrus saltator.
Gammaridea is one of the suborders of the order Amphipoda, comprising small, shrimp-like crustaceans. Until recently, in a traditional classification, it encompassed about 7,275 (92%) of the 7,900 species of amphipods described by then, in approximately 1,000 genera, divided among around 125 families. That concept of Gammaridea included almost all freshwater amphipods, while most of the members still were marine.
Ochlesidae is a family of amphipods. They are very small, often less than 1.5 millimetres (0.06 in) long, and are found mainly in tropical and subtropical areas of the Southern Hemisphere. The family Odiidae has sometimes been subsumed into Ochlesidae.
Phliantidae is a family of isopod-like amphipod crustaceans chiefly from the southern hemisphere.
Oedicerotidae is a family of amphipods. It comprises the following genera:
Lysianassidae is a family of marine amphipods, containing the following genera:
Chiltonia is a genus of amphipod crustaceans endemic to New Zealand. Four species are known, three of which live in fresh waters. They were first discovered by Charles Chilton in 1898 and the genus Chiltonia was erected the following year by T. R. R. Stebbing in Chilton's honour.
Leucothoidae is a family of amphipods. It contains 138 species in 5 genera:
Gammaridae is a family of amphipods. In North America they are included among the folk taxonomic category of "scuds", and otherwise gammarids is usually used as a common name.
Cyproideidae is a family of amphipod crustaceans. Eighteen genera and 43 species have been described as of 2009. They mostly occur mostly in the Southern Hemisphere, where they form associations with corals, sponges, crinoids and hydroids.
Photis is a genus of amphipod crustaceans, containing the following species:
Iphimedia is a genus of amphipods which belongs to the family Iphimediidae in the arthropod group Amphipoda. It is the only genus of the family to have species which live in tropical waters. All other genera of the family are only found in cold or deep oceans.
Amphilochus is a genus of crustaceans in the Amphipoda order, containing the following species:
Pontogeneiidae is a family of amphipod crustaceans, containing the following genera:
Stegocephalidae is a little-studied family of amphipods belonging to the suborder Gammaridea.
Martensia martensi is a species of amphipod crustacean, and the only species in the genus Martensia. It occurs in waters around Svalbard at depths of 37–95 metres (121–312 ft).
Paramoera walkeri is an amphipod of the genus Paramoera. It lives around Antarctica.
Talitrida is an infraorder of amphipods in the subclass Senticaudata.
Maeridae is a family of marine amphipods, which was first described by Taudl Krapp-Schickel in 2008.
