Family Atyidae De Haan, 1849

Diagnosis (from [7]): freshwater shrimps from small to large size (4–120 mm). Body usually pigmented, except for some subterranean species. Ocular peduncle without projection on the dorsal margin near the cornea. Last two articles of antennular peduncle longer or as long as wide; stylocerite without dorsal process, or vestigial one. Mandibles without palp but with a well-developed molar process. Exopodite of maxillae with a posterior tuft of long setae. Exopodite of third maxillipeds prolonged by a transverse or oblique projection on its antero-internal angle; epipodites of third maxilliped very reduced or vestigial, without posterior lobe. Dactylus of second maxilliped longer or as long as propodus. Dactylus of third maxilliped armed with a rather strong spine, arched and never styliform. Chelipeds with simple carpus and ending in a chela. Dactylus of walking legs moderately long, flattened or conical, armed with a terminal spine and a series of spinules, and numerous and contiguous on the fifth pereiopods. Epipods always lack a projection. Telson without median stylus on its posterior margin.