Crustacea, the Higher Taxa

J.K. Lowry

Astacidea (Decapoda, Eucarida, Malacostraca)

Common name. Clawed Lobsters (Freshwater Crayfish, True Lobsters, Reef Lobsters, Scampi, Dublin Bay Prawns).

Description. Head. Rostrum present; eyes stalked or absent; compound, visual elements present; ocular scale absent; naupliar eyes absent. Antennules (antenna 1) biramous; peduncle and flagellum distinct; endopod well developed; exopod well developed, whip-like. Antennae (antenna 2) biramous; exopod multiarticulate, or exopod forming a scaphocerite. Mandible uniramous; palp present, or absent. Maxillipeds, 3 pairs; biramous. Thorax. Carapace present, univalved, enclosing head and thorax, subcylindrical to cylindrical, smooth or with spines. Sternum undivided, or divided. Thorax and abdomen differentiated. Peraeopods (legs) 5 pairs; uniramous; non-phyllopodous; differentiated (some prehensile). Peraeopod 1 (leg 1) chelate. Peraeopod 2 (leg 2) chelate. Peraeopod 3 (leg 3) chelate, about the same size as other legs. Peraeopod 5 (leg 5) well developed. Abdomen with 6 somites. Epimera present. Pleopods present, 5 pairs; reduced; pleopod 2 forming a gonopod (eg. appendix masculina) in males. Uropods well developed, 1 pair, positioned ventrolaterally; rami present, exopod with diaresis, partial or complete; endopod without statocyst. Telson present (not fused to pleon).

Larval development. Epimorphic, or metamorphic. Embryos attached to pleopods.

Habitat. Marine, brackish, freshwater or semiterrestiral.

Distribution. Worldwide except for Africa and parts of Asia.

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