Crustacea, the Higher Taxa

J.K. Lowry

Anomura (Decapoda, Eucarida, Malacostraca)

Common name. Hermit Crabs, Sand Crabs, Mole Crabs, Porcelain Crabs, Squat Lobsters, Stone Crabs.

Description. Head. Rostrum present or absent; eyes stalked; compound, visual elements present; ocular scale absent; naupliar eyes absent. Antennules (antenna 1) biramous, or uniramous; peduncle and flagellum distinct; endopod reduced, vestigial or absent; exopod reduced, vestigial or absent. Antennae (antenna 2) biramous, or uniramous; exopod multiarticulate. Mandible uniramous; palp present, or absent. Maxillipeds, 3 pairs; biramous. Thorax. Carapace present, univalved, enclosing head and thorax, subcylindrical to cylindrical or dorsoventrally flattened, smooth or with spines. Sternum divided. Thorax and abdomen differentiated. Peraeopods (legs) 5 pairs; uniramous; non-phyllopodous; differentiated (some prehensile). Peraeopods 2-5 (legs) basis and ischium free, or basis and ischium fused. Peraeopod 1 (leg 1) simple, or chelate. Peraeopod 2 (leg 2) simple, or chelate. Peraeopod 3 (leg 3) simple. Peraeopod 5 (leg 5) reduced. Abdomen present, well developed or present, reduced in size and folded under thorax, abdomen with 6 somites. Epimera present or absent. Pleopods present; reduced; none modified into reproductive organ in males, or pleopod 1 forming a gonopod (eg. petasma) in males. Uropods well developed, 1 pair, positioned ventrolaterally; rami present, exopod without diaresis; endopod without statocyst. Telson present (not fused to pleon), or absent.

Larval development. Metamorphic. Embryos attached to pleopods.

Habitat. Marine, infrequently semiterrestrial or freshwater.

Distribution. Worlwide.




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/.