Mysidacea: Families, Subfamilies and Tribes

Kenneth Meland

Diagnostic description. Head. Carapace short, last 2 or 3 thoracic somites exposed dorsally. Rostrum elongated (forming a small triangular apex). Eyes normally developed. Antenna (antenna 2) scale with apical suture, outer margin smooth, setose, without terminal spine. Labrum asymmetric (produced posteriorly into two unequal lobes). Mandible lacinia mobilis well developed, spine row present between lacinia mobilis and molar process, molar process well developed.

Thorax. 1st maxilliped exopod well developed (endopod's dactylus expanded, possessing a free distal margin armed with spines). 2nd thoracopod developed as a maxilliped, exopod well developed. 3rd-8th thoracopods endopod with fused carpus and propodus (tarsus), carpopropodus divided into a few subsegments. Branchiae on thoracopods absent. Marsupium composed of three pairs of oostegites.

Abdomen 6th & 7th abdominal somites fused. Female pleopods uniramous or greatly reduced. Uropod endopod inner margin with robust setae, statocyst present; exopod complete, setose around entire margin. Telson apex cleft.

Generic composition. Mysidellinae contains 1 genus (8 species): Mysidella G.O. Sars, 1872 (8 species).

Remarks. These hyperbenthic mysids are with the exception of the Tasmanian Mysidella australiensis Fenton, 1990 described from northern temperate waters of the Pacific and Atlantic Ocean.

The subfamily Mysidellinae is easily distinguished from other mysids by the conspicuous labrum which is produced posteriorly into two unequal lobes and the first maxilliped having a modified endopod dactylus possessing a free distal margin armed with spines. Also note that the male pleopods are reduced to unsegmented plates resembling those seen in the tribe Heteromysini.

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