Crustacea, the Higher Taxa

J.K. Lowry

Oniscidea (Isopoda, Peracarida, Malacostraca)

Common name. Slaters, Pill Bugs, Wood Lice.

Description. Head. Rostrum absent; eyes sessile or absent; compound, visual elements present; ocular scale absent; naupliar eyes absent. Antennules (antenna 1) minute; peduncle and flagellum distinct; exopod well developed, whip-like; statocyst absent. Antennae (antenna 2) uniramous; exopod multiarticulate. Mandible uniramous; palp present. Maxillipeds, 1 pair. Thorax. Carapace absent. Thorax and abdomen differentiated. Peraeopods (legs) 7 pairs, or 6 pairs; uniramous; non-phyllopodous; undifferentiated (simple); coxae not forming lateral plates, or some coxae forming lateral plates. Abdomen with 6 somites or with 5 somites. Epimera present. Pleopods present, 5 pairs; well developed, broad and flat; pleopod 2 forming a gonopod (eg. appendix masculina) in males, or 1 and 2 forming reproductive organ in males. Uropods well developed, 1 pair, positioned ventrolaterally or positioned terminally or subterminally; rami present (uniramous); endopod without statocyst. Telson present (not fused to pleon), or fused to pleon (pleotelson).

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

Habitat. Terrestrial, moist forest floors and gardens; occasionally commensals in termite and ant nests.

Distribution. Worldwide.

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