Crustacea, the Higher Taxa

J.K. Lowry

Amphipoda (Peracarida, Malacostraca)

Common name. Beachhoppers, Landhoppers, Scuds, Sea Fleas, Skeleton Shrimps.

Description. Head. Rostrum present or absent; eyes sessile or stalked or absent, eyes paired and lateral or contiguous or fused dorsally; eyes compound, visual elements present, or visual elements absent; eyes ocular scale absent; eyes naupliar eyes absent. Antennules (antenna 1) biramous, or uniramous; peduncle and flagellum distinct; endopod well developed, or endopod reduced, vestigial or absent; exopod well developed, whip-like; statocyst absent. Antennae (antenna 2) uniramous, or reduced, vestigial or absent; exopod multiarticulate. Mouthparts not highly modified, or modified to form suctorial cone, or atrophied. Mandible uniramous; palp present, or absent. Maxillipeds, 1 pair; uniramous. Thorax. Carapace absent. Thorax and abdomen differentiated. Peraeopods (legs) 7 pairs, or 5 pairs; uniramous; non-phyllopodous; differentiated (some prehensile); some coxae forming lateral plates. Peraeopod 1 (leg 1) simple, or chelate, or subchelate. Peraeopod 2 (leg 2) simple, or chelate, or subchelate. Peraeopod 3 (leg 3) simple or subchelate. Abdomen present, well developed or present, vestigial, abdomen with 6 somites or with 5 somites or with 4 somites. Epimera present. Pleopods present, 3 pairs; well developed, narrow and rounded. Uropods well developed or vestigial or absent, 2 to 3 pairs, positioned ventrolaterally; rami present or rami absent; subrectangular to subquadrate, or lanceolate; exopod with diaresis, partial or complete or exopod without diaresis (uropod 3); endopod without statocyst. Telson present (not fused to pleon), or absent.

Larval development. Epimorphic. Embryos carried in ventral thoracic brood pouch.

Habitat. Benthic and planktonic, marine, freshwater and terrestrial; free-living and commensals, one group is parasitic.

Distribution. Worldwide.

Cite this publication as: Lowry, J.K. (1999 onwards). 'Crustacea, the Higher Taxa: Description, Identification, and Information Retrieval.' Version: 2 October 1999. http://crustacea.net/.