Gnathophausia Willemoes-Suhm, 1873

Meland, Kenneth & Aas, Pål Øyvind, 2013, A taxonomical review of the Gnathophausia (Crustacea, Lophogastrida), with new records from the northern mid-Atlantic ridge, Zootaxa 3664 (2), pp. 199-225 : 200

Gnathophausia Willemoes-Suhm, 1873

Gnathophansia ―Willemoes-Suhm, 1873: 400–403 (lapsus calami). Gnathophausia Willemoes-Suhm, 1875: 28 –37.—Humbert, 1874: 206. Neognathophausia Petryashov, 1992: 47 –48.

Type species: Gnathophausia gigas Willemoes-Suhm, 1873 .

Diagnosis. Carapace large, externally provided with raised keels, anterior end produced into long rostrum, in some species posterior margins are produced into posteriorly directed dorsal spine and/or lateral spines; rostrum and posterodorsal spine three sided with denticulate longitudinal ridges. Eyes with well-developed papilla. Antennular peduncle short and thick, with relatively broad and long outer flagella. Antennal scale of varying form, apical suture in most species. Paragnaths are asymmetrical, subunits of paragnaths and mandibles interlock; lacinia mobilis on right mandible absent; incisor process of left mandible is semicircular in shape, lacinia mobilis displaced to center of biting edge. Maxillule with bisegmented endopod. Maxilla with well developed exopod supporting pigmented luminous organ at base. First thoracopod developed as maxilliped; exopod lancet-shaped, very small or absent; lamellar epipod present, producing respiratory current. Second thoracopod developed as pereopod, exopod reduced. Third to eighth thoracopods take on form of pereopods, exopods present, epipodites on second to seventh thoracopods formed as branchiae, divided into four irregularly-lobed branches, eighth thoracic limb epipodites imperfectly developed. Marsupium consisting of seven pairs of oostegites arising from base of second to eigth thoracopods. Six abdominal somites, pleural plates bilobed, well-developed; sixth somite divided by transverse groove. Exopods of uropods broader than endopods, with transverse subapical suture. Telson distinct, containing two long keels on dorsal surface, armed with series of spines along the lateral margins, two curved spines form crescent at apex.

Remarks. The genus Gnathophausia was erected by W. -Suhm (1873) for the placement of two new species, G. gigas and G. z o e a. First referred to as Gnathophansia, which was evidently a typographical error, this was promptly corrected to Gnathophausia by Humbert (1874), and later confirmed in a more detailed description of the genus by W. -Suhm (1875). Udrescu (1984) erected a new Lophogastrida family, Gnathophausiidae , to contain the genera Gnathophausia Willemoes-Suhm, 1873 and later, Neognathophausia Petryashov, 1992 .