Crustacea, the Higher Taxa

J.K. Lowry

Phreatoicidea (Isopoda, Peracarida, Malacostraca)

Description. Head. Rostrum absent; eyes sessile or absent; compound, visual elements present; ocular scale absent; naupliar eyes absent. Antennules (antenna 1) uniramous; peduncle and flagellum distinct; exopod well developed, whip-like; statocyst absent. Antennae (antenna 2) uniramous; exopod multiarticulate. Mandible uniramous; palp present, or absent. Maxillipeds, 1 pair. Thorax. Carapace absent. Thorax and abdomen differentiated. Peraeopods (legs) 7 pairs, or 6 pairs; uniramous; non-phyllopodous; undifferentiated (simple); some coxae forming lateral plates. Peraeopod 1 (leg 1) subchelate. Peraeopod 2 (leg 2) simple. Peraeopod 3 (leg 3) simple. Abdomen with 5 somites. Epimera absent. Pleopods present, 5 pairs; well developed, broad and flat; pleopod 2 forming a gonopod (eg. appendix masculina) in males (check position). Uropods 1 pair, positioned ventrolaterally or positioned terminally or subterminally; rami present, exopod with diaresis, partial or complete; endopod without statocyst. Telson fused to pleon (pleotelson).

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

Habitat. Freshwater, semiterrestrial.

Distribution. South Africa, India, New Zealand, Australia.

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