Gnathophausia longispina G.O. Sars, 1883

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 : 208-209

Gnathophausia longispina G.O. Sars, 1883

( Fig. 6 )

Gnathophausia longispina G.O. Sars, 1883: 8 –9.—G.O. Sars 1885: 46–48. —Ortmann 1906: 41–42. —Hansen 1910:17.—Fage 1941: 39–41.—Bacescu 1991: 82–84. —Casanova 1996a: 129.

Diagnosis. Carapace covering entire thorax; rostrum elongate and slender, can be twice length of carapace, denticulate; posterodorsal spine long and strongly developed, can project to about end of fourth abdominal somite, denticulate along lateral and dorsal edges continuing onto dorsal keel of carapace; dorsal keel continuous, extending posteriorly onto posterodorsal spine; upper lateral keels present; lower lateral keels runs parallel with anterior margin and turns upward towards posterodorsal spine, merging into upper keel; supra-orbital spines present; antennal spines absent; branchiostegal expansions very large, acute triangular. Antennal scale very large, tapers rapidly toward apex, outer apical spine of antennal scale extending far beyond terminal lobe and is coarsely denticulate on inner and outer edges. Abdominal somites with small posterodorsal spines; ventral pleural spines prominent, spines on pleura of second somite remarkably long and slender, posterior margin of last segment supports two, somewhat upturned spines. Telson as long as uropods; linguiform, distal two-thirds of lateral margins armed with spiniform setae; apex armed with two pairs of large spiniform setae, posterior margin fringed with a serrated edge. Obtains lengths of 60 mm (G.O. Sars 1885; Ortmann 1906).

Distribution. G. longispina is restricted to Pacific waters. It has been collected in the China Sea, Philippines, Makassar Strait, Wallis and Futuna Islands, and off Hawaii at depth ranges from 400 to 1000m.

Remarks. G. longispina bears resemblance to G. z o e a, but is easily distinguished from all Gnathophausia species by the combination of a long apical spine on the outer margin of the antennal scale and the conspicuous triangular branchiostegal spines.

Figures

FIGURE 6. Gnathophausia longispina G. O. Sars, 1883. Adult male A, lateral view; B, dorsal view; C, antenna D, telson (from G. O. Sars 1885: pl. VII, figs. 1 – 4).