Nephropsis ensirostris Alcock, 1901

Chang, Su-Ching & Chan, Tin-Yam, 2019, On the clawed lobsters of the genus Nephropsis Wood-Mason, 1872 recently collected from deep-sea cruises off Taiwan and the South China Sea (Crustacea, Decapoda, Nephropidae), ZooKeys 833, pp. 41-58 : 41

Nephropsis ensirostris Alcock, 1901 Figs 1C, D, 4

Nephropsis ensirostris Alcock, 1901: 158, pl. 1-fig. 2 (type locality: north of the Laccadives, Arabian Sea); Macpherson 1990: 303, figs 5a, 6, 8a, b, 16a; Holthuis 1991: 41, figs 71, 72; Chan 1997: 414; 2010: 157.

Material examined.

Zhongsha 2015, stn CP4137, 19°53.059'N, 114°21.678'E, 536-524 m, 23 Jul 2015, 1 male cl 12.1 mm (NTOU M01831), 1 female cl 14.6 mm (NTOU M02071).

Diagnosis.

Carapace finely granulate. Rostrum more than half carapace length, without lateral spine. Median groove reaching or overreaching midpoint of rostrum. Each subdorsal carina with none or two spines and several granules. Gastric tubercle located closer to orbital border than to postcervical groove. Supraorbital and post-supraorbital spines present. Postcervical groove deep, passing dorsal midline of carapace. Pair of dorsal spines located just behind postcervical groove. Distance between orbital border and postcervical groove less than twice distance between postcervical groove and posterior border of carapace.

Abdominal tergites I–V with conspicuous transverse grooves. Dorsal median carina present on tergites II–VI. Anterior borders of pleura II–V granulated, spineless, terminating in a long, acute point. Anterior border of pleuron II more convex than those of other pleura. Uropodal exopod with distinct but incomplete diaeresis.

Cheliped I with little pubescence; carpus with well-developed anterodorsal spine, outer spine on terminal half and inner spine at about mid-length. Carpus of pereiopod II slightly longer than palm. Carpus of pereiopod III more than half palm length. Dactyli of pereiopods IV and V approximately 2/3 propodus length.

Color in life.

Body generally pinkish to whitish, with rostrum, tail fan, and antennal and antennular flagella reddish. Eyes whitish.

Distribution.

This species has been reported in the Indian Ocean along Gulf of Aden, Laccadive Sea, Bay of Bengal to Andaman Sea. In the western Pacific it is only known from Indonesia and the Philippines. The present material extends its distribution to near Dongsha in the South China Sea. Bathymetric depth ranges from 315 to 1314 m ( Macpherson 1990; Holthuis 1991; Chan 1997; Zarenkov 2006).

Remarks.

Nephropsis ensirostris can be readily distinguished from other species of the genus by lacking a lateral spine on the rostrum. The two small specimens collected off west of Dongsha agree well with the description of Macpherson (1990), except for the spines on the subdorsal carina are missing in the male (Fig. 4B; see also Chan 1997). These spines are present in Macpherson’s (1990) material as well as in the female specimen reported here (Figs 1D, 4A).