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
Author
Forges, Bertrand Richer De
Author
Ng, Peter K. L.
Author
Ahyong, Shane T.
text
Zootaxa
2013
3635
1
15
26
journal article
10.11646/zootaxa.3635.1.2
49b09288-829c-4211-ad42-c58847dccb4d
1175-5326
283510
D35BD9A0-5251-4517-8C94-CB3BC7FB3C23
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).
FIGURE 1
.
Parapleisticantha japonica
Yokoya, 1933
. Lectotype male (22.4 × 16.8 mm) (KMNH), Goto Is., Japan. A, habitus; B, dorsal view of carapace; C, ventral view of cephalothorax showing epistome, antennules and antennae.
FIGURE 2
.
Parapleisticantha japonica
Yokoya, 1933
. Lectotype male 22.4 × 16.8 mm (KMNH), Goto Is., Japan. A, frontal view showing rostrum and eyes; B, ventral view showing anterior thoracic sternum and abdomen; C, left third maxilliped; D, lateral view of carapace; E, outer view of left chela.
FIGURE 3
.
Parapleisticantha
japonica
Yokoya, 1933
. Paralectotype ovigerous female (16.6 x 13.1 mm) (KMNH), Goto Is., Japan. A, habitus; B, dorsal view of carapace; C, ventral view showing anterior thoracic sternum and abdomen.
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.