The Ampithoidae Boeck, 1871, are an abundant group of corophiidean amphipods found in shallow tropical to temperate marine environments worldwide. They are herbivorous, primarily inhabiting macroalgae and seagrasses (Poore & Lowry, 1997). The taxon contains 13 genera and two subgenera which are divided between two subfamilies – the Ampithoinae and the Exampithoinae (Myers & Lowry, 2003). Of these, the genus Ampithoe is the most abundant, containing in excess of 79 species globally (Peart, 2007b).
Presented here is an interactive identification key to world ampithoid genera, and the species of the Australian and Northeast Atlantic regions. Fourty-four Australian species are included, as well as 12 species from the North Atlantic, thus incorporating just under half of the known world species.