Mysidacea: Families, Subfamilies and Tribes

Kenneth Meland

Diagnostic description. Head. Carapace large, last 2 or 3 thoracic somites exposed dorsally. Rostrum obtuse. Eyes normally developed. Antenna (antenna 2) scale with apical suture, outer margin smooth, without setae, with terminal spine. Labrum symmetric. Mandible lacinia mobilis well developed, spine row present between lacinia mobilis and molar process, molar process well developed.

Thorax. 1st maxilliped exopod well developed. 2nd thoracopod developed as a maxilliped, exopod well developed. 3rd-8th thoracopods endopod with distinct carpus and propodus, propodus divided into two or three subsegments. Branchiae on thoracopods absent. Marsupium composed of seven pairs of oostegites.

Abdomen 6th & 7th abdominal somites fused. 1st pair biramous; 2nd pair exopod elongated; 3rd pair exopod elongated; 4th pair biramous; 5th pair biramous. Female pleopods uniramous or greatly reduced. Uropod endopod setose around entire margin, statocyst present; exopod with proximal articulation, outer margin with slender and robust setae (proximal end entire ending in two or three spines, distal margin setose). Telson apex cleft.

Generic composition. Boreomysidae contains 2 genera (38 species): Boreomysis G.O. Sars, 1869 (36 species); Birsteiniamysis Tchindonova, 1981 (2 species).

Remarks. The Boreomysinae are generally mesobathypelagic mysids, widely distributed throughout the worlds oceans.

These are the only mysids of the suborder Mysida displaying a primitive marsupium consisting of seven pairs of oostegites, which led Tchindonova (1981) to place the sub-family Boreomysinae within a new family Boreomysidae, removing them from the family Mysidae. She also established the genus Birsteiniamysis for Boreomysis caeca Birstein & Tchindonova, 1958 and B. inermis (W.-Suhm, 1874). Not all authors recognize Tchindonova's classification, retaining the genus Boreomysis within the Mysidae subfamily Boreomysinae.

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