Lissosabinea unispinosa Komai, 2006

[New Japanese name: Hitotoge-tachi-ebi-jyako]

Fig. 1

Lissosabinea unispinosa Komai, 2006: 53, figs. 13–16 [type locality: New Caledonia, 465 m deep].— Taylor & Collins 2009: 176 (key), fig. 7.—De Grace & Fransen 2011: 456.

Material examined. T/RV “Toyoshio-maru”, 2002-05 cruise, stn 9, E of Aguni Island, Okinawa Islands, 26°30.72’N, 127°25.99’E, 439–487 m, 26 May 2002, beam trawl, 1 male (cl 3.5 mm), CBM-ZC 8027; 2010-03 cruise, stn 5, E of Amami-oshima Island, 27°58.66’N, 129°24.60’E, 404–408 m, 24 May 2010, beam trawl, 1 male (cl 3.6 mm), CBM-ZC 11263.

Distribution. Previously known from New Caledonia and Tonga in the South-West Pacific, at depths of 410–610 m (Komai, 2006). The present specimens greatly extend the geographical range of this species to the north and west.

Remarks. The genus Lissosabinea Christoffersen, 1988 is represented by eight species, of which vast majority occur in the South-West Pacific (Komai, 2006; Taylor & Collins, 2009). From Japanese waters, only L. indica (de Man, 1918) is heretofore known (Kim & Natsukari 2000; Komai, 2011). Diagnostic characters of Lissosabinea include a pair of lateral teeth on the rostrum (cf. Fig. 1A, B), lack of conspicuous lateral carinae on the carapace posterior to the orbit (Fig. 1B), and very short, non-chelate, simple pereopod 2 (Fig. 1F) (Holthuis, 1993; Komai, 2006). Lissosabinea unispinosa is readily distinguished from other seven congeners by having only one middorsal spine (epigastric in the position) on the carapace (cf. Fig. 1A, B). In the other seven species, the carapace has two or three prominent middorsal spines. As shown by Komai (2008), the other diagnostic characters useful for the species recognition are: the pleomere 3 tergum is not markedly elevated or sharply carinate in the midline (Fig. 1C); the merus of the pereopod 1 bears a sharp spine located at the midlength of the ventral margin and a moderately strong dorsodistal spine (Fig. 1D); and the palm of the subchela has a strongly oblique occlusal margin (Fig. 1E). The present specimens agree well with the original description of L. unispinosa (cf. Komai, 2006) and represent the second record since the original description.