Carcinoplax specularis Rathbun, 1914

Ng, Peter K. L. & Castro, Peter, 2020, A revision of Carcinoplax abyssicola (Miers, 1885) and seven related species of Carcinoplax H. Milne Edwards, 1852, with the description of two new species and an updated key to the genus (Crustacea, Decapoda, Brachyura, Goneplacidae), Zoosystema 42 (17), pp. 239-284 : 256-260

Carcinoplax specularis Rathbun, 1914

( Figs 10 A-H; 11 A-I; 12 A-I; 25 A-E; 27 D)

Carcinoplax specularis Rathbun, 1914: 143 [ Philippines].

Carcinoplax specularis – Serène 1968: 90 [in list]. — Sakai 1969: 270, fig. 15c [holotype]. — Takeda & Yaganisawa 1985: 61 [in list] [ Japan]. — Guinot 1989: 296, figs 25, 34; pl. 8, figs A-D [holotype] [ Philippines]. — Ho et al. 2004: 659, fig. 6F (colour) [ Taiwan]. — Ng et al. 2008: 80 [in list].

? Carcinoplax specularis – Serène & Vadon 1981: 119, 120, 123, 126 [ Philippines].

Carcinoplax specularis [part] – Castro 2007: 640 [ Taiwan, Philippines].

Carcinoplax longipes – Sakai 1976: 524 [in key], 527, fig. 281 [ Japan] (not C. longipes (Wood-Mason, 1891)) .

? Carcinoplax longipes – Miyake 1991: 220 [in list] [ Japan]. — Takeda et al. 2006: 204 [in list] [ Japan]. — Takeda & Yaganisawa 1985: 61 [in list] [ Japan] (not C. longipes (Wood-Mason, 1891) , either C. specularis s. str. or C. verdensis Rathbun, 1914 ).

Not Carcinoplax specularis [part] – Castro 2007: 640 (= C. polita Guinot, 1989 ).

Not Carcinoplax specularis [part] – Castro 2007: 640 . (= C. tuberosa Castro, 2007 ).

Not Carcinoplax specularis [part] – Castro 2007: 640 (= C. verdensis Rathbun, 1914 ).

Not Carcinoplax specularis [part] – Castro 2007: 641 (? = C. fasciata Ng & Kumar, 2016 )

TYPE MATERIAL. — Holotype. Philippines. ♂, 16.7 × 23.0 mm, Albatross ; stn 5113; 17.I.1908; USNM 46164 .

TYPE LOCALITY. — Philippines, off southern Luzon, Sombrero I., S. 7°W., 9.5 miles, 13°51’30”N, 120°50’30”E, 159 fathoms (= 291 m).

MATERIAL EXAMINED. — Taiwan • 1 ♂, 14.2 × 19.9 mm; TAIWAN 2001; stn CP77, 24°54.2’N, 122°02.5’E; 220-360 m depth; 7.V.2001; MNHN-IU-2016-122 (= MNHN-B29821 ) • 1 ♂, 16.5 × 22.5 mm; same data as MNHN-IU-2016-122; MNHN-IU-2016-123 (= MNHN-B29822 ) ; • 1♂, 18.4 × 25.8 mm, 1 ♀, 13.2 × 17.8 mm; TAIWAN 2001; stn CP85; 24°0.65’N, 122°0.64’E; 255-390 m depth; 9.V.2001; ZRC 2001.0134 • 1 ♀, ovigerous 1 ♂; TAIWAN 2001; stn CP96; 24°04.2’N, 122°04.2’E; 472-586 m depth; 18.V.2001; MNHN-IU-2016-124 (= MNHN-B29823 ) • 1 ♀, 12.4 × 16.7 mm; TAIWAN 2001; stn CP104; 24°48.9’N, 122°05.3’E; 365-447 m depth; 10.V.2001; MNHN-IU-2016-125 (= MNHN-B29824 ) .

Philippines • 1 ♂, 12.5 × 17.9 mm; PANGLAO 2005; stn CP2359, Bohol Sea ; 08°49.9’N, 123°34.9’E; 437-476 m depth; 26.V.2005; ZRC 2018.1435 • 2 ♀; PANGLAO 2005; stn CP2372, Dipolog Bay, Bohol Sea ; 8°38.7’N, 123°16.0’E; 27.V.2005; ZRC 2018.1436 • 1 ♀, 13.9 × 18.0 mm; PANGLAO 2005; stn CP2407, Maribohoc Bay ; 09°41.3’N, 123°48.5’E, 256-268 m depth; ZRC 2006.0207 • 2 ♂; AURORA; stn CP2731, Luzon Sea ; 15°22.44’N, 121°33.58’E - 15°24.48’N, 121°33.51’E; 376-391m; 31.V.2007; ZRC 2018.1437 • 4 ♀, largest 10.5 × 15.7 mm, 2 ♂, larger one 1.0 × 15.0 mm; AURORA; stn CP2734, Luzon Sea ; 15°56.41’N, 121°48.71’E - 15°56.98’N, 121°49.21’E; 453-460 m depth; 1.VI.2007; ZRC 2018.1438 .

DIAGNOSIS. — Carapace ( Figs 10A, B ; 11A, B ; 12A, B ) quadrate, slightly wider than long (1.4 × wider than long in holotype); slightly convex, marked by slight transverse elevations. Front ( Figs 10C, D ; 11C, D ; 12C, D ) straight, notch between front, inner edge of supraorbital border absent. Triangular or rounded tooth on outer orbital angle; two slender, acute or obtuse anterolateral teeth on each side of carapace. Small, short granules on subhepatic, pterygostomial regions ( Figs 10D ; 11D ; 12D ), becoming slightly more pronounced in pterygostomial crest, ridge. Posterior margin of epistome ( Figs 10D ; 11D ; 12D ) straight, slightly pointed medially, slight gap or notch on each lateral margin. Distal half of fingers dark brown in females ( Fig. 12A, F, I ), two-thirds in males ( Fig. 11A, I ). Smooth, oblong “window” on inner, dorsal surface of cheliped propodi of some males, including holotype ( Figs 10F ; 11G ). Inner (ventral), distal margin of cheliped carpus ( Figs 10F ; 11F, G ; 12F ) with short, blunt or acutetipped tooth. P2-P5 ( Figs 10A ; 11A ; 12A ; 27D ) moderately stout in appearance. Male pleon ( Figs 10G ; 11F ) proportionally narrow. G1 ( Fig. 25 A-D; Guinot 1989: fig. 34A) slender; truncated tip with scattered spinules that do not reach distal margin; G2 ( Fig. 25E ; Guinot 1989: fig. 34B) slender, nearly equal or slightly longer than G1, slightly curved flagellum, tip with two lateral spinules.

COLOUR IN LIFE. — Light orange with a semi-circular row of small white spots on each side of the carapace ( Fig. 27D ; Ho et al. 2004: fig. 6F).

GEOGRAPHICAL DISTRIBUTION. — Japan, Taiwan, and Philippines.

DEPTH. — Present in samples collected at depths of 220- 586 m.

REMARKS

Larger males show a “window”, an oblong, slightly darker spot on the inner, dorsal surface of the cheliped propodi ( Figs 10F ; 11G ), that was previously noted in the holotype by Rathbun (1914) and Guinot (1989). It has not been observed in females. Such a “window” was also observed by us in C. abyssicola and C. adelphia n. sp. For differences with C. adelphia n. sp., see the remarks for the latter species.

Carcinoplax specularis was found together with C. verdensis and C. jugum n. sp. from one station in the Philippines (CP2359).

Three specimens of C. tuberosa Castro, 2007 from Kai Is, Indonesia (MNHN-IU- 2016-98 (= MNHN-B29385), MNHN-IU-2016-101 (= MNHN-B29390), and MNHN- IU-2016-102 (= MNHN-B29392)) were erroneously identified as C. specularis by Castro (2007).

Two ovigerous females from the Maldives (John Murray Expedition, stn 143, 05°15.8’N, 73°22.8’E - 05°13.7’N, 73°23.6’E, 797 m depth; 30.III.1934, MNH 2007.64-65) identified as C. specularis by Castro (2007: 641) most probably belong to a different species of Carcinoplax , with Ng & Kumar (2016) suggesting it was likely to be C. fasciata Ng & Kumar, 2016 instead. The specimens in the NHM could not be located for re-examination (see Ng & Kumar 2016: 199).

Figures

FIG. 10. — Carcinoplax specularis Rathbun, 1914, holotype ♂ (16.7 × 23.0 mm) (USNM 46164), Philippines:A, overall habitus; B, dorsal view of carapace; C, frontal view of cephalothorax; D, posterior margin of epistome; E, left third maxilliped; F, right cheliped; G, thoracic sternum and pleon; H, outer view of chelae.

FIG. 11. — Carcinoplax specularis Rathbun, 1914, ♂ (18.4 × 25.8 mm) (ZRC 2001.0134), Taiwan: A, overall habitus; B, dorsal view of carapace; C, frontal view of cephalothorax; D, posterior margin of epistome; E, left third maxilliped; F, dorsal view of carpus of right cheliped; G, dorsal view of right chela; H, thoracic sternum and pleon; I, outer view of chelae.

FIG. 12. — Carcinoplax specularis Rathbun, 1914, ♀ (12.4 × 16.7 mm) (MNHN-IU-2016-125), Taiwan: A, overall habitus;B, dorsal view of carapace;C, frontal view of cephalothorax; D, posterior margin of epistome; E, right third maxilliped; F, dorsal view of carpus of right cheliped; G, thoracic sternum and pleon; H, sternopleonal cavity and vulvae; I, outer view of chelae.

FIG. 25. — Gonopods: A-E, Carcinoplax specularis Rathbun, 1914, holotype ♂ (16.7 × 23.0 mm) (USNM 46164), Philippines; F-I, C. adelphia n. sp., holotype ♂ (19.4 × 25.4 mm) (MNHN-IU-2016-8002), Vanuatu; J-P, C. fasciata Ng & Kumar, 2016, holotype ♂ (25.8 × 19.3 mm) (DABFUK), India; Q-T, C. jugum n. sp., holotype ♂ (33.6 × 45.5 mm) (ZRC 2004.0777), Philippines. A, right G1 (dorsal view), B, right g1 (ventral view); C, distal part of right G1 (ventral view); D, distal part of right G1 (dorsal view); E, right G2; F, J, Q, left G1 (ventral view); G, K, R, distal part of left G1 (ventral view); H, L, S, distal part of left G1 (dorsal view); I, M, D, Q, left G2; N, right G2; O, P, distal part of right G2. A, after Guinot (1989: fig. 34A). Scale bars: A, B, E, F, I, J, M, N, Q, T, 1.0 mm; C, D, G, H, K, L, R, S, 0.5 mm; O, P, 0.25 mm.

FIG. 27. — Colour in life: A, Carcinoplax longipes (Wood-Mason, 1891), ♂ (9.0 × 12.4 mm) (ZRC 2018.1422), Java; B, C. longipes, ♂ (10.8 × 14.4 mm) (ZRC 2018.1427), Java; C, C. longipes, ovigerous ♀ (10.8 × 14.3 mm) (ZRC 2018.1420), Java; D, C. specularis Rathbun, 1914, ♂ (18.4 × 25.8 mm) (ZRC 2001.0134), Taiwan; E, C. adelphia n. sp., paratype ♂ (15.7 × 21.2 mm) (ZRC 2009.0922), Vanuatu; F, C. adelphia n. sp., paratype ♀ (16.9 × 22.4 mm) (ZRC 2009.0922(, Vanuatu; G, C. polita Guinot, 1989, ♀ (12.8 × 17.8 mm) (ZRC 2006.0176), Philippines; H, C. polita, ♂ (6.5 × 7.9 mm) (ZRC 2018.1417), Java. Photographs: A-C, SJADES; D, P.-H. Ho; E-H, T.-Y. Chan.