Crustacea, the Higher Taxa

J.K. Lowry


Euphausiacea (Eucarida, Malacostraca)

Common name. Krill.

Description. Head. Rostrum present or absent; eyes stalked; compound, visual elements present; ocular scale absent; naupliar eyes absent. Antennules (antenna 1) biramous; peduncle and flagellum distinct; endopod well developed; exopod well developed, whip-like. Antennae (antenna 2) biramous; exopod forming a scaphocerite. Mandible uniramous; palp present, or absent. Maxillipeds, absent. Thorax. Carapace present, univalved, enclosing head and thorax, laterally compressed, smooth. Thorax and abdomen differentiated. Peraeopods (legs) 8 pairs; biramous; non-phyllopodous; undifferentiated (simple), or differentiated (some prehensile). Abdomen with 6 somites. Epimera present. Pleopods present, 5 pairs; 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 with diaresis, partial or complete or exopod without diaresis (partially developed); endopod without statocyst. Telson present (not fused to pleon).

Larval development. Anamorphic. Eggs shed or deposited externally (or briefly brooded).

Habitat. Marine pelagic.

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/.