Mysidacea: Families, Subfamilies and Tribes

Kenneth Meland

Diagnostic description. Head. Carapace large, last 2 or 3 thoracic somites exposed dorsally. Rostrum plate-like. Eyes normally developed. Antenna (antenna 2) scale without apical suture, outer margin serrated, without setae, without terminal spine. Labrum symmetric. Mandible left mandible lacinia mobilis well developed to lacinia mobilis reduced or absent (right mandible armed with fixed cusp in position of the lacinia mobilis), spine row absent, molar process well developed.

Thorax. 1st maxilliped exopod small, unarticulated. 2nd thoracopod developed as a gnathopod, exopod reduced. 3rd-8th thoracopods endopod with distinct carpus and propodus, propodus unsegmented. Branchiae on thoracopods present. Marsupium composed of seven pairs of oostegites.

Abdomen Abdomen pleural plates well developed (fringed with backwardly projecting ventral spines). 6th & 7th abdominal somites incompletely fused. Female pleopods biramous. Uropod endopod setose around entire margin, statocyst absent; exopod complete, outer margin entire. Telson apex entire.

Generic composition. Lophogastridae contains 5 genera (34 species): Ceratolepis G.O. Sars, 1883 (1 species); Chalaraspidum W.-Suhm, 1875 (1 species); Lophogaster M. Sars, 1857 (21 species); Paralophogaster Hansen, 1910 (10 species); Pseudochalaraspidum Birstein & Tchindonova, 1962 (1 species).

Remarks. The Lophagastridae are generally considered pelagic mysids having a worldwide distribution, inhabiting both coastal and oceanic waters. As in the other members of the sub-order Lophogastrida these mysids display several primitive characters: thoracic gills, seven pairs of oostegites, incomplete fusion of the sixth and seventh abdominal somites, large, natatory female pleopods, absence of the right lacinia mobilis, and most noticable the absence of a statocyst in the endopod of the uropod.

See Fukuoka et al. (1997) for recent additions to the family Lophogastridae.

Cite this publication as: 'Meland, K. (2002 onwards). Mysidacea: Families, Subfamilies and Tribes. Version 1: 2 October 2002. https://crustacea.net'.