Crustacea, the Higher Taxa

J.K. Lowry

Thermosbaenacea (Peracarida, Malacostraca)

Description. Head. Rostrum absent; eyes stalked or absent; visual elements absent; ocular scale absent; naupliar eyes absent. Antennules (antenna 1) biramous; peduncle and flagellum distinct; endopod reduced, vestigial or absent; exopod well developed, whip-like. Antennae (antenna 2) uniramous; exopod multiarticulate. Mandible uniramous; palp present. Maxillipeds, 1 pair; biramous, or uniramous. Thorax. Carapace present, univalved, enclosing head and anterior thoracic somites or enclosing first and second thoracic somites or enclosing head, thorax and part of the abdomen (check), laterally compressed, smooth. Thorax and abdomen differentiated. Peraeopods (legs) 7 pairs, or 6 pairs, or 5 pairs; biramous; non-phyllopodous; undifferentiated (simple). Peraeopod 1 (leg 1) simple. Peraeopod 2 (leg 2) simple. Peraeopod 3 (leg 3) simple. Abdomen with 6 somites. Epimera absent. Pleopods present, 2 pairs; well developed, narrow and rounded, or reduced. Uropods 1 pair, positioned ventrolaterally; rami present, exopod with diaresis, partial or complete; endopod without statocyst. Telson present (not fused to pleon), or fused to pleon (pleotelson).

Larval development. Epimorphic. Embryos carried dorsally within the carapace.

Habitat. Thermal springs, fresh, brackish and anchialine.

Distribution. North Atlantic, Mediterranean and south-eastern Indian Ocean.

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