Parapleisticantha japonica Yokoya 1933
Creators: name: Forges, Bertrand Richer De
name: Ng, Peter K. L.
name: Ahyong, Shane T.
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Inachidae
Parapleisticantha
Parapleisticantha japonica

description: Parapleisticantha japonica Yokoya, 1933
(Figs. 1–3, 6A–E)
Parapleisticantha japonica Yokoya, 1933: 140, text-fig. 50.—Ng & Richer de Forges 2012: 65.
Pleistacantha (Parapleisticantha) japonica.—Sakai 1938: 238; 1940: 55.
Pleistacantha japonica. —Takeda & Miyake 1969: 494, pl. 18, fig. A, text-figs 9c, d.—Sakai, 1976: 174; 1986: 2, 3, text figure 1.—Ahyong et al. 2005: 1–8.
Not Pleistacantha japonica.— Guinot & Richer de Forges 1982: 112, fig. 7A, pl. III, 4, 4a.
Material examined. Japan, southeast of Goto Is., station 431, 152 m, coll. R/V Soyo-Maru, 16 July 1929 (KMNH): lectotype male (22.4 × 16.8 mm), 1 paralectotype ovigerous female (16.6 × 13.1 mm).
Comparative material. Pleistacantha sanctijohannis: Philippines, Balicasag Is., 200–300 m, tangle nets, coll. P.K.L. Ng, June 2002 (ZRC 2002.0669): 3 males (16.6 × 13.1 mm, 17.9 × 15.2 mm, 13.6 × 9.7 mm), 2 ovigerous females (19.9 × 16.1 mm, 18.4 × 15.4 mm).— Pleistacantha cervicornis: Philippines, station CP 2380, 8°41.3’N, 123°17.8’E, 163–271 m, coll. PANGLAO 2005, 28 May 2005 (ZRC): 1 male (21.3 × 15.8 mm), 8 ovigerous females (20.4 × 15.6 mm, 18.9 × 14.4 mm, 15.2 × 11.3 mm, 16.6 × 12.5 mm, 17.9 × 12.9 mm, 16.8 × 13.3 mm, 15.6 × 11.7 mm, 15.9 × 12.1 mm); Vanuatu, station AT 27, 15°22.4’S, 167°15.4’E, 339–345 m, coll. SANTO 2006, 23 September 2006 (ZRC): 1 ovigerous female (17.5 × 13.9 mm); Vanuatu, station AT 28, 15°23.6’S, 167°16.1’E, 342–350 m, 23 September 2006: 1 male (11.6 × 7.9 mm), 1 ovigerous female (14.9 × 11.2 mm).— Pleistacantha oryx: Philippines, station CP 2716, 14°31’N, 121°60.8’E, 311–361 m, coll. AURORA 2007, 29 May 2007 (ZRC): 1 male (25.7 × 18.8 mm, photographed).— Philippines, Balicasag Is., from fishermen by tangle nets, coll. P.K.L. Ng, 2 March 2004 (ZRC): 1 ovigerous female (27.0 × 23.6 mm).— Japan, Sagami Sea, Okinose, 540 m, Mortensen Expedition, 28 June 1942 (AM P34571): 2 males (26.1 × 18.2 mm, 27.0 × 19.4 mm), 2 ovigerous females (22.1 × 16.5 mm, 25.3 × 19.0 mm).
Description. Small-sized species (ovigerous female less than 17 mm long); carapace regularly covered with short spiniform granules, spinules; larger spines arranged as follows: 5 on gastric area, 2 on cardiac area, 2 on branchial area; branchial regions gently convex (Figs. 1 A, B, 2A, 3A, B). Rostrum horns diverging, forming Vshape (Figs. 1, 2 A, 3); each horn relatively short, with 2 lateral accessory spines (1 proximal, 1 shorter near midlength); ventral face of horns with 2 strong spines; distal border of antennular fossa with distal spine pointing outward; 2 sharp postocular; subhepatic tooth comparatively long (Figs. 1 C, 2A). Eyes with short peduncle, small rounded cornea (Figs. 1, 2 A, 3). Supraorbital eave large, border with 3 or 4 teeth; supraocular spine short; intercalated spine small, infraocular spine longest (Figs. 1, 2 A, D, 3). Hepatic region with several spines, longest pointing outwards (Figs. 1, 2 A, D, 3). Interantennular spine (true rostrum) bifid (Fig. 2 A). Basal antennal article long with 6 long spines arranged on border of article, 3 internal, 3 external (Figs. 1 C, 2A, D). Third maxilliped pediform: ischium with 2 longitudinal rows of sharp granules on outer surface, lateral row with 5 granules, mesial row with 3 granules; merus subtriangular, longer than broad, with 2 sharp granules on outer surface (Fig. 2 C). Male chelipeds with strong chelae, inflated palm; dactylus with 2 large teeth on inner border; cross-section of merus trigonal, each angle with a row of sharp spines; propodal margin below articulation of dactylus and pollex with distinct subtruncate granulated process; cutting edge of propodal finger with distinct, evenly sized teeth (Figs. 1 A, 2E). Ambulatory legs long; P2 longest, merus shorter than carapace length (0.91 cl in lectotype); P5 merus 0.62 cl (male lectotype), 0.48 cl (paralectotype female); merus with subdistal dorsal spine; dorsal and ventral margins lined with sharp spinules (Figs. 1 A, 3A). Abdomen of both sexes with 6 free somites and telson; distal margin of somite 6 deeply concave (Fig. 2 B). G1 stout, straight along basal two-thirds, distal part sharply bent outwards, forming 90° angle, lined with setae on straight part, distal part without subdistal process (Fig. 6A–C); G2 about half as long as G1, tip spatuliform (Fig. 6E). Ovigerous female smaller than males with chelipeds not inflated (Fig. 3 A), body relatively more setose than males (Fig. 3); abdomen dome-shaped, covering entire thoracic sternum (Fig. 3 C).
Remarks. The two specimens used in the diagnosis are syntypes as Yokoya did not select a holotype. The male specimen is here designated the lectotype, the female as paralectoype. Parapleisticantha japonica is presently known only from Japan. The small female attributed to P. japonica from New Caledonia (MNHN B7275, 16.5 × 10.0 mm; Guinot & Richer de Forges 1982) has been re-examined and represents a species of Pleistacantha currently under study.
description: Published as part of Forges, Bertrand Richer De, Ng, Peter K. L. & Ahyong, Shane T., 2013, Parapleisticantha Yokoya, 1933, a valid genus of deep-sea inachid spider crab from Japan and the Philippines (Crustacea: Decapoda: Brachyura: Majoidea), with the description of a new species, pp. 15-26 in Zootaxa 3635 (1) on pages 17-21, DOI: 10.11646/zootaxa.3635.1.2, http://zenodo.org/record/283510