Psopheticoides sanguineus Sakai, 1969

CASTRO, PETER & NG, PETER K. L., 2010, Revision of the family Euryplacidae Stimpson, 1871 (Crustacea: Decapoda: Brachyura: Goneplacoidea), Zootaxa 2375 (1), pp. 1-130 : 89-93

publication ID

https://doi.org/ 10.11646/zootaxa.2375.1.1

DOI

https://doi.org/10.5281/zenodo.6317859

persistent identifier

https://treatment.plazi.org/id/03F487A8-3904-4278-7D8C-FCB9F645FD0F

treatment provided by

Felipe

scientific name

Psopheticoides sanguineus Sakai, 1969
status

 

Psopheticoides sanguineus Sakai, 1969 View in CoL

( Figs. 36A–G View FIGURE 36 ; 38D–F View FIGURE 38 ; 39C View FIGURE 39 )

Psopheticoides sanguineus Sakai, 1969: 274 View in CoL , figs. 16b, 17a, a', b, 18b, c; 1976: 528, fig. 282, pl. 192, fig. 3 [ Japan]. — Serène & Vadon 1981: 120, 123, 127 [ Philippines] — Takeda 1982: 19 [list]; 2001: 248 (as Propheticoides [sic]), 251, 258 [list] [ Japan]. — Miyake 1991: 220 [in list] [ Japan]. — Castro 2007: 620 [discussion] [ Philippines, Tonga] — Ng et al. 2008: 78, fig. 63 [colour photograph] [in list].

Type material. Male holotype ( USNM 125888 View Materials ) ; 1 female paratype (unknown status)

Type locality. Japan, Kyushu , Tosa Bay, off Mimase, 100–150 m.

Material examined. Philippines. Bohol. Balicasag I., off Panglao I., 200–300 m, tangle nets of local fishermen, 12.2000 : 2 females ( ZRC 2001.0366 View Materials ) ; 50–500 m, 28.11.2001: 4 males, 1 female, 2 ovigerous females ( ZRC 2001.0539 View Materials ) ; 200–300 m, 06.2002: 1 male, 1 female ( ZRC 2002.0651 View Materials ) ; 25– 30.07.2003: 8 males, 1 female, 17.7 mm × 22.3 mm ( ZRC 2004.0752 View Materials ) ; 02.03.2004: 2 ovigerous females ( ZRC 2004.0713 View Materials ) ; 11.2003: 1 male, 2 females, 3 ovigerous females ( ZRC) ; 12.2003: 1 male ( ZRC 2008.1359 View Materials ) ; 02.2004: 1 ovigerous female ( ZRC 2008.1360 View Materials ) ; 05.2004: 2 males ( ZRC) .

Panglao I., Maribojoc Bay , 100–300 m, T. J. Arbasto coll., 11.2003 –04.2004: 1 ovigerous female ( ZRC 2008.1361 View Materials ) GoogleMaps ; 28.05.2004: 1 male, 21.9 mm × 27.8 mm ( ZRC 2008.1357 View Materials ) ; 07.2004 –05.2005: 1 ovigerous female, 1 female ( ZRC 2008.1362 View Materials ) GoogleMaps .

PANGLAO 2004: stn. P1, Nato coll., 30.05.2004: 1 male, 22.0 mm × 26.7 mm, 1 female, 20.1 mm × 25.3 mm ( MNHN-B29728 ). Vanuatu. SANTO 2006: no data: 1 male, 7.8 mm × 9.8 mm ( ZRC 2009.0974 View Materials ) .

Tonga. BORDAU 2: stn. DW 1634, 21°45’S, 175°20’W, 321–322 m, 20.06.2000: incomplete specimen ( MNHN-B29808 ) GoogleMaps .

Diagnosis. Reniform eyes ( Fig. 36B View FIGURE 36 ). Orange-red circle on dorsal surface of carapace ( Fig. 39C View FIGURE 39 ).

Remarks. A large but damaged and incomplete specimen from Tonga (MNHN-B29808) clearly shows the characteristic carapace, including the colour spot.

Colour pattern. A distinctive orange-red circle fringed by a yellow-white border located on the cardiac region of the carapace ( Fig. 39C View FIGURE 39 ; Ng et al. 2008: fig. 63). The rest of the carapace and the ambulatory legs are orange-red.

Distribution. Western Pacific from Japan to the Philippines, Vanuatu, and Tonga. Depth: 50– 322 m.

Genus Systroplax n. gen.

Carcinoplax View in CoL — Tesch 1918: 154 (part). — Rathbun, 1914b: 142. — Serène 1968: 89 [in list] (part). — Sakai 1969: 269 (part). — Serène & Lohavanijaya 1973: 62, 63 [key to species] (part). — Guinot 1989: 273 (part). — Chen 1998: 266 [key to species] (part). [not Carcinoplax H. Milne Edwards, 1852 View in CoL ]

Diagnosis. Carapace ( Fig. 37A View FIGURE 37 ) suboctagonal, nearly round; front long, nearly straight (outer edges slightly arched in large individuals), marked by small median notch; transverse sulcus along margin; notch between front, supraorbital border. Orbits short, spherical ( Fig. 37B View FIGURE 37 ); supraorbital borders short, arched, with 2 notches; suborbital borders arched, 2 very small notches in larger individuals; large, granular, ventrally oriented inner suborbital tooth ( Fig. 37B, C View FIGURE 37 ); eye peduncles short, granular; large, spherical corneas. Anterolateral borders arched, 2 short, obtuse anterolateral teeth; posterolateral borders long, arched. Dorsal, ventral surface of carapace with short, spherical granules ( Fig. 37B, C View FIGURE 37 ), strongly convex, without clear indication of regions. Outer orbital angle with very short, triangular tooth; 2 obtuse, small anterolateral teeth on each side of carapace, first larger (much reduced or absent in large individuals, particularly second tooth; Fig. 38I, J View FIGURE 38 ). Basal antennal article immobile, with distolateral process so that orbital hiatus is closed excluding antennal flagellum from orbit ( Fig. 37B, C View FIGURE 37 ). Outer (ventral) surface of third maxilliped carpus, merus granular, anteroexternal margin of merus auriculiform ( Fig. 37C View FIGURE 37 ). Subhepatic, pterygostomian regions, pterygostomian crest granular. Thoracic sternum ( Fig. 37E, G View FIGURE 37 ) wide, granular outer margins; thoracic suture 2/3 complete, straight ( Fig. 37E, G View FIGURE 37 ); 3/4 deep, short, interrupted; 4/5, 5/6, 6/7, 7/8 interrupted ( Fig. 37G View FIGURE 37 ); median groove on thoracic sternites 7, 8 ( Fig. 37G View FIGURE 37 ). Sterno-abdominal cavity of male deep, reaching median portion of sternite 4 ( Fig. 37E View FIGURE 37 ). Press-button of male abdominal-locking mechanism as tubercle near thoracic suture 4/5 (presence in pre-adult females unknown). Anteroexternal margin of third maxilliped merus auriculiform. Cheliped (P1) propodus, carpus, merus granular (inner surface of propodus relatively smooth); fingers moderately stout, slightly shorter than swollen propodus, tips darker in colour ( Fig. 37D View FIGURE 37 ). Carpus with long, blunt tooth on distal, inner margin; merus with large, blunt tooth on inner surface near anterior margin. Dorsal margins of ambulatory legs (P2–P5) meri, carpi, propodi unarmed, dactyli slender, smooth, setose; P5 dactyli, propodi proportionally short, flattened, fringed with scattered, long setae, spines. Male abdomen narrow, slender (Tshaped), lateral margins of somites 4–6 abruptly narrowing from somite 3 to transversely narrow, pointed telson ( Fig. 37E View FIGURE 37 ); somite 3 reaching inner margins of P5 coxae, outer end fitting under episternite 7; somite 2 transversely shorter than somite 3 but no portions of thoracic sternite 8 exposed by closed abdomen ( Fig. 37F View FIGURE 37 ). G1 long, slender, slightly sinuous, acuminate apex, with small denticles ( Fig. 38G View FIGURE 38 ). G2 less than onethird of G1, straight, with 2 processes: one long, tip acute; second much shorter, small, lobe-like ( Fig. 38H View FIGURE 38 ). Male genital opening (gonopore) coxal; coxo-sternal disposition of long penis with very broad, soft proximal expansion, protected by concave posterior portion of thoracic sternite 7. Female abdomen relatively narrow, not covering outer portions of thoracic sternum, with six freely-mobile somites. Telson broadly triangular, wider than long. Somites 1, 2 cover space between P5 coxae, only small portion of each P5 condyle of sternite 8 left exposed by closed abdomen ( Fig. 37F View FIGURE 37 ). Vulva of mature females ovoid, extending across median portion of thoracic sternite 6 close to median axis of thorax ( Fig. 37G View FIGURE 37 ); covered by soft membrane, sternal vulvar cover absent.

Type species. Carcinoplax angusta Rathbun, 1914 (by present designation, gender feminine).

Etymology. From systremma, Greek for anything aggregated, generally a ball or round object, in reference to the diagnostic round shape of the carapace of the type species, and plax, Greek for “plate” or “tablet”, which is derived from the generic name Carcinoplax (from karkinos, Greek for crab), to denote that the species included in the new genus was formerly included in the latter.

Remarks. Although the carapace shape is superficially similar to two species assigned to the family Goneplacidae sensu stricto (i.e. Carcinoplax tenuidentata Castro, 2007 , and Pycnoplax bispinosa (Rathbun, 1914) ; Castro 2007: figs. 5, 13B), Systroplax n. gen. clearly belongs to the Euryplacidae ( Castro 2007: 623) . The male abdomen is slender, with a narrow and pointed telson ( Fig. 37E View FIGURE 37 ), and the G1, also slender, is much longer than the G2. Although the shape of the abdomen of goneplacids varies, it is typically broad and triangular and a similarly shaped telson (i.e. Castro 2007: figs. 4B, 16B), never narrow as in the Euryplacidae . The G 1 in Carcinoplax H. Milne Edwards, 1852 , is never as slender as in euryplacids and the apex is much wider, never acuminate (e.g. Castro 2007: fig. 2), or thick and stout as in Pycnoplax Castro, 2007 (e.g. Castro 2007: fig. 16C). A G2 much shorter than the G1, however, is present in three goneplacid genera ( Castro 2007). The vulva of Systroplax n. gen. is typical of euryplacids, relatively small with thick margins and no sternal vulvar cover, in contrast to the much expanded vulva of Carcinoplax (e.g. Castro 2007: fig. 1), or the vulva covered by a sternal vulvar cover of Pycnoplax (e.g. Castro 2007: fig. 15).

In contrast to most euryplacids, thoracic suture 5/6 is interrupted, a character nevertheless shared with Nancyplax and Xenocrate ( Table 1).

Species included. Systroplax angusta (Rathbun, 1914) The genus is restricted to the Indo-West Pacific region.

ZRC

Zoological Reference Collection, National University of Singapore

Kingdom

Animalia

Phylum

Arthropoda

Class

Malacostraca

Order

Decapoda

Family

Euryplacidae

Genus

Psopheticoides

Loc

Psopheticoides sanguineus Sakai, 1969

CASTRO, PETER & NG, PETER K. L. 2010
2010
Loc

Psopheticoides sanguineus

Ng, P. K. L. & Guinot, D. & Davie, P. 2008: 78
Castro, P. 2007: 620
Miyake, S. 1991: 220
Takeda, M. 1982: 19
Serene, R. & Vadon, C. 1981: 120
Sakai, T. 1969: 274
1969
Loc

Carcinoplax

Chen, H. 1998: 266
Guinot, D. 1989: 273
Serene, R. & Lohavanijaya, P. 1973: 62
Sakai, T. 1969: 269
Serene, R. 1968: 89
Tesch, J. J. 1918: 154
Rathbun, M. J. 1914: 142
1918
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