Gammaridea

Gammaridea is a suborder of small, shrimp-like crustaceans in the order Amphipoda. It contains about 7,275 (92%) of the 7,900 described species of amphipods, in approximately 1,000 genera, divided among around 125 families. Gammaridea includes almost all freshwater amphipods (such as Gammarus pulex), but most of its members are marine. The group may be paraphyletic, and a 2003 revision by Myers and Lowry moved several families from Gammaridea to join members of the former Caprellidea in a new suborder Corophiidea.