Nephropsis acanthura Macpherson, 1990

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 acanthura Macpherson, 1990 Figs 1A, B, 3

Nephropsis acanthura Macpherson, 1990: 311, figs 5d, 9 d–f, 11a, b, 16d (type locality: Philippines); Holthuis 1991: 35, figs 61, 62; Chan 1997: 413; 2010: 156; Poore 2004: 166, fig. 43b; Zarenkov 2006: 85, fig. 3; Poore et al. 2008: 34.

Material examined.

TAIWAN 2003, stn CD210, 24°28.99'N, 122°12.79'E, 500-1183 m, 1 Jun 2003, 1 female cl 10.6 mm (NTOU M00951). TAIWAN 2006, stn PCP343, 22°15.699'N, 120°2.131'E, 945-1059 m, 8 Mar 2006, 1 female cl 8.9 mm (NTOU M00952).

Diagnosis.

Carapace finely granulate. Rostrum longer than half carapace length, bearing a pair of strong lateral spines. Median groove on rostrum extending anteriorly beyond lateral rostral spines. Subdorsal carinae granulate. Supraorbital spines well developed. Postcervical groove passing dorsal midline of carapace. Distance between orbital border and postcervical groove slightly less than twice distance between postcervical groove and posterior border of carapace.

Abdomen with tergites II–VI bearing conspicuous median carina. Anterior border of pleuron II convex and bearing some spinules, terminating in long, acute point. Anterior border of pleura III–V less convex and also terminating in long, acute point. Strong erect dorsal spine present near base of telson. Uropodal exopod with complete diaeresis.

Carpus of cheliped I with strong anterordorsal spine; outer surface without spine; inner border with a spine somewhat at middle of carpus. Carpus of pereiopod II shorter than palm. Carpus of pereiopod III approximately 2/3 palm length. Dactyli of pereiopods IV and V slightly longer than half propodus length.

Color in life.

Body generally reddish with dorsal carapace and abdomen whitish. Eyes whitish.

Distribution.

Widely distributed in the Indo-West Pacific: Madagascar, Indonesia, Australia, Coral Sea, New Caledonia, Tasman Sea, Chesterfield Islands, the Philippines, southern Japan ( Macpherson 1990; Holthuis 1991; Griffin and Stoddart 1995; Chan 1997; Poore 2004; Zarenkov 2006; Poore et al. 2008), and now Taiwan. The bathymetric depth ranges from 500-1305 m.

Remarks.

Nephropsis acanthura is reported from Taiwan for the first time. This species and N. occidentalis Faxon, 1893 are the only two species in the genus bearing an erect spine near the base of the telson ( Macpherson 1990; Holthuis 1991). The two Taiwanese specimens fit well with the characteristics of N. acanthura in the carapace bearing numerous small granules, the rostrum longer than half carapace length, and the abdominal pleura II-V terminating in a long, acute point (see Macpherson 1990; Holthuis 1991). Nevertheless, there are some variations noticed in the present material compared with those reported by Macpherson (1990). In the Taiwanese specimens, the dactyli of pereiopods IV and V (Fig. 3C) are slightly longer than half propodus length (vs. less than half). The median groove on the rostrum extends beyond the lateral rostral spines (vs. terminating at the level of lateral rostral spines). The distance between the orbital border and postcervical groove is slightly less (vs. slightly more) than twice the distance between the postcervical groove and posterior border of carapace. Additionally, it is reported that the carapace is less granular in the Indonesian material ( Chan 1997).