Crustacea, the Higher Taxa

J.K. Lowry


Polychelida (Decapoda, Eucarida, Malacostraca)

Description. Head. Rostrum absent; eyes immovable, not protruding above carapace and not pigmented; visual elements absent; ocular scale absent; naupliar eyes absent. Antennules (antenna 1) biramous; peduncle and flagellum distinct; endopod well developed; exopod well developed, whip-like (shorter than endopod). Antennae (antenna 2) uniramous; exopod multiarticulate. Mandible uniramous; palp present, or absent. Maxillipeds, 3 pairs; biramous. Thorax. Carapace present, univalved, enclosing head and thorax, dorsoventrally flattened, smooth. Sternum undivided. Thorax and abdomen differentiated. Peraeopods (legs) 5 pairs; uniramous; non-phyllopodous; differentiated (some prehensile). Peraeopods 2-5 (legs) basis, ischium and merus fused. 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; lateral knob-like structure on pleonite 1 fits into socket on posterior margin of carapace. Epimera present. Pleopods present, 5 pairs or 4 pairs (check); well developed, narrow and rounded, or reduced. Uropods well developed, 1 pair, positioned ventrolaterally; rami present, exopod without diaresis; endopod without statocyst. Telson present (not fused to pleon).

Larval development. Metamorphic. Embryos attached to pleopods.

Habitat. Marine deep sea.

Remarks. Polychelids were removed from the Palinura by Scholtz and Richter (1995) and placed in the Polychelida.

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/.