Carcinoplax verdensis 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 : 260-264

Carcinoplax verdensis Rathbun, 1914

( Figs 13 A-J; 14 A-H; 15 A-G; 24 A-H; 28 A-F)

Carcinoplax verdensis Rathbun, 1914: 143 [type locality: southern Luzon, Philippines]. — Tesch 1918: 154 [in list]. — Estampador 1937: 533 [in list]; 1959: 89 [in list] [ Philippines]. — Serène 1968: 90 [in list]. — Sakai 1969: 269 [in list], fig. 15d [holotype]. — Serène & Lohavanijaya 1973: 62 [in list], 65 [in key]. — Serène & Vadon 1981: 119, 123, 126 [ Philippines]. — Guinot 1989: 300, fig. 22; pl. 9, figs D-F [holotype] [ Philippines]. — Ng et al. 2008: 80 [in list].

Carcinoplax longipes – Chen 1984: 189 [in key], 195, 197, fig. 6 [East China Sea]. — Ikeda 1998: 15, 42, 135, pl. 55 [ Japan] (not C. longipes (Wood-Mason, 1891)) .

Carcinoplax aff. longipes – Guinot 1989: 305, figs 27, 35, 36; pl. 10, figs D-G [ Philippines].

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

Not Carcinoplax verdensis – Selvaraj & Kathirvel 1980: 159, figs 1, 2 [ India] ( C. indica Doflein, 1904 ).

TYPE MATERIAL. — Holotype. Philippines • Ovigerous ♀, 10.5 × 13.0 mm; Albatross; stn 5119; USNM 46167 .

TYPE LOCALITY. — Philippines, off Sombrero I., Verde I. Passage, 159-394 fathoms (= 291-721 m),

MATERIAL EXAMINED. — Taiwan • 1♂ (badly damaged); stn CP19, southwestern Taiwan ; 22°24.2’N 120°10.2’E - 22°23.8’N 120°09’E; 467-634 m depth; coll. T.-Y. Chan; 29.VII.2000; ZRC 2001.2216 . Philippines. 1 ovigerous ♀, holotype 10.5 × 13.0 mm; Albatross, stn 5119, off Sombrero I., Verde I. Passage; 291-721 m depth; 21.I.1908; USNM 46167 • 1 ♀; MUSORSTOM 3, stn CP116; 12°32’N, 120°47’E; 804-812 m depth; 3.VI.1985; MNHN-IU-2016-8001 • 2 ♀, 9.2 × 12.1 mm, 12.0 × 16.7 mm, 8 ♂ (2 with bopyrids); MUSORSTOM 3, Bohol , Balicasag I., off Panglao I., tangle nets of local fishermen; 09°31’00.2”N, 123°40’50.5”E; 200-300 m depth; XII.2000; ZRC 2001.0395 • 1 ♀; MUSORSTOM 3, tangle nets of local fishermen; 09°31’00.2”N, 123°40’50.5”E; 200- 300 m depth; XII.2000; ZRC 2019.0544 • 1 ♂, 14.9 × 20.2 mm; PANGLAO 2005, stn CP2332, Maribohoc Bay ; 09°38.8’N, 123°45.9’E; 396-418 m depth; 22.V.2005, ZRC 2019.0547 , ex ZRC 2006.0214 (part) • 1 ♀, 5.8 × 8.1 mm; PANGLAO 2005, stn DW2338, off Balicasag Island ; 09°30.7’N, 123°42.4 ‘E; 347-349 m depth; 23.V.2005; ZRC 2019.0548 • 1 ♂, 19.0 × 27.7 mm; PANGLAO 2005, stn CP2339, off Balicasag Island ; 09°31.9’N, 123°43.7’E, 164-176 m depth; 23.V.2005; ZRC 2019.0550 • 1 ♀, 10.9 × 14.4 mm; same data as ZRC 2019.0550; ZRC 2019.0573 • 1 ♂, 3.8 × 4.8 mm; PANGLAO 2005, stn CP2359, Bohol Sea ; 08°49.9’N, 123°34.9’E; 437-476 m depth; 26.V.2005, ZRC 2019.0553 • 1 ♂, 15.7 × 21.4 mm, ZRC 2019.0549 • 1 juvenile ♂; same data as ZRC 2019.0549; ZRC 2009.0990 • 2 ♀, 12.4 × 17.1 mm, 13.0 × 18.3 mm; PANGLAO 2005, stn CP2361, Bohol Sea ; 08°53.1’N, 123°33.5’E; 516-543 m depth; 26.V.2005; ZRC 2019.0554 • 11 ♀ (1 with rhizocephalan), 4 ♂, 1 juvenile; PANGLAO 2005, stn CP2384, off Aligbay Island ; 08°46.2’N, 123°16.1’E; 624-647 m depth; 29.V.2005; ZRC 2019.0546 • 1 ♂, 16.9 × 23.0 mm; PANGLAO 2005, stn CP2385; 08°51.0’N, 123°10.0’E, 982-989 m depth; 29.V.2005; ZRC 2009.1003 • 1 ♂, with sacculinid; PANGLAO 2005, stn CP2386; 08°49.3’N, 123°01.9’E, 2120-2149 m depth (?); 29.V.2005; ZRC 2019.0556 • 1 ♀, 10.9 × 14.6 mm; PANGLAO 2005, stn CP2388, Maribohoc Bay ; 09°26.9’N, 123°34.5’E; 762-786 m depth; 30.V.2005, ZRC 2019.0551 • 2 ♂, 11.6 × 15.4 mm, 11.0 × 14.6 mm; same data as ZRC 2019.0551; ZRC 2019.0571 • 2 ♂, larger one 19.2 × 27.7 mm, 2 ♀; PANGLAO 2005, stn CP2389, Bohol Sea ; 09°27.9’N, 123°38.4’E; 784- 786 m depth; 30.V.2005; ZRC 2019.0555 • 2 ♂, 9.6 × 12.0, 12.8 × 17.1 mm; PANGLAO 2005, stn CP2394, off Balicasag Island ; 09°28.6’N, 123°40.0’E; 470-566 m depth; 30.V.2005: ZRC 2019.0557 • 1 ♂, 10.0 × 13.4 mm; same data as ZRC 2019.0557; ZRC 2019.0574 • 3 ♂, 8.7 × 10.1 mm, 9.8 × 11.8 mm, 17.6 × 13.7 mm; PANGLAO 2005. stn CP2396, west Panglao , on sandy bottom; 09°36.3’N 123°42.0’E; 673- 715 m depth; 31.V.2005; ZRC 2016.0446 • 2 ♂, 1 ♂, 13.2 × 16.1 mm with sacculinid; PANGLAO 2005, stn CP2405, on sandy-muddy bottom; 09°39.0’N 123°46.1’E, 1.VI.2005; ZRC 2006.0199 • 1 ♂, 1♀, (both with bopyrids); PANGLAO 2005, stn CP2358, Bohol Sea ; 08°52.1’N, 123°37.1’E; 569-583 m depth; 26.V.2005; ZRC 2016.0439 • 1 ♂ (with bopyrid); PANGLAO 2005, stn CP2396, Maribojoc Bay , 09°36.3’N, 123°42.0’E; 609- 673 m depth; 31.V.2005; ZRC 2016.0447 • 1 ♂, (with bopyrid); PANGLAO 2005, stn CP2405, Maribojoc Bay ; 09°39.0’N, 123°46.1’E; 387-453 m depth; 1.VI.2005; ZRC 2016.0436 • 1 ♀ (with bopyrid), station unknown; Bohol Sea ; V-VI 2005; ZRC 2016.0441 • 1 ♀, 12.8 × 17.9 mm; AURORA 2007, stn CP2673, Luzon Sea ; 14°59.83’N, 121°43.90’E - 15°01.44’N, 121°44.75’E; 431-493m; 22.V.2007; ZRC 2019.0559 • 1 ♀, 7.9 × 10.9 mm; AURORA 2007, stn DW2692, Luzon Sea ; 14°40.15’N, 123°40.06’E - 14°40.45’N, 123°40.59’E; 261- 272 m depth; 26.V.2007; ZRC 2019.0560 .

South China Sea • 1 ♀, ovigerous 9.4 × 13.0 mm; NANHAI 2014, stn CP4117, LL4; 20°00.8788’N, 114°08.7974’E; 333- 421 m depth; 11.I.2014, ZRC 2019.0561 • 1 ♀, 1 ♂; same data as stn CP4117; ZRC 2019.0210 • 1 ♀; ZHONGSHA 2015, stn CP4155, northeast of Macclesfield Bank ; 16°13.60’N, 115°01.61’E; 510-526 m depth; 28.VII.2015; ZRC 2019.0562 • 1 ♂, 11.1 × 16.0 mm; ZHONGSHA 2015, stn CP4165, south of Taiwan Bank ; 22°09.888’N, 118°42.023’E; 443-618 m depth; 1.VIII.2015; ZRC 2019.0563 • 1 ♀; ZHONGSHA 2015, stn CP4166, south of Taiwan Bank ; 22°07.6245’N, 118°43.3003’E; 587-756 m depth; 1.VIII.2015; ZRC 2019.0564 • 1 ♀, 6.8 × 8.8 mm; ORI3 CRUISE, stn 9, Tungsha Is , 21°40.293’N 117°43.244’E - 21°38.995’N 117°41.649’E; 523- 510 m depth; coll. I.-S. Chen; 9.VII.2011; ZRC 2019.0374 .

DIAGNOSIS. — Carapace ( Figs 13A, B ; 14A, B ; 15A, B ) quadrate, slightly wider than long (1.4 × wider than long in holotype); slightly convex, slight transverse elevations, slight tomentum. Front ( Figs 13C, D ; 14C, D ; 15C ) straight, notch on each lateral margin absent or slight if present. Rounded, short tooth on outer orbital angle; two slender, acute-tipped anterolateral teeth on each side of carapace. Small, short granules on subhepatic, pterygostomial regions ( Figs 13D ; 14D ), becoming more pronounced in pterygostomial crest, ridge; short granules on anterior, dorsal surface of carapace. Posterior margin of epistome ( Figs 13D ; 14D ) straight, slight median emargination in some specimens, shallow notch on each lateral margin. Distal half of fingers dark brown in females ( Figs 13A, I, J ; 15A ), two third in males ( Fig. 14A, H ). “Window” not observed on outer surface of cheliped propodus. Inner (ventral), distal margin of cheliped carpus ( Figs 13F ; 14F ; 15E ) with acute, conspicuous tooth. P2-P5 ( Figs 13A ; 14A ; 15A ; 28 A-F) slender in appearance. Male pleon proportionally wide ( Fig. 14G ). G1 ( Fig. 24 A-C, E, G) slender; pointed tip with scattered spinules, abundant, almost reaching margin of tip in some individuals; G2 ( Fig. 24D, F, H ) slender, nearly equal or slightly longer than G1, slightly curved flagellum, tip with two lateral spinules.

COLOUR IN LIFE. — Orange carapace that intensifies with age, at least in females ( Fig. 27 D-F). The legs (P2-P5) of females show thin, red bands across the middle portion. Males are orange without any banding on the legs ( Fig. 27 A-C).

GEOGRAPHICAL DISTRIBUTION. — Japan, East China Sea, Taiwan, Philippines, and South China Sea.

DEPTH. — Present in samples collected at depths of 164-989 m; 2120-2149 m in one station, possibly an error.

REMARKS

See Remarks for C. abyssicola .

The relatively long, acute, and conspicuous tooth on the inner distal angle of the cheliped carpus ( Figs 13F ; 14F ; 15E ) is a good character to distinguish C. verdensis , with most specimens showing this character. No other species treated here has this character. Some specimens (e.g. 1 ♀, 12.8 × 17.9 mm, ZRC 2019.0559) have lower, more obtuse cheliped carpal spines, not acute and elongated as is typical specimens.

Guinot (1989), who only observed the holotype, separated C. verdensis because of the absence of the “window” of C. specularis , the acute anterolateral teeth, and relatively more slender legs (P2-P5). The ambulatory meri of C. verdensis are indeed one of the longest in the group (see remarks for C. abyssicola ), although in a few specimens, the legs are somewhat shorter (e.g. Fig. 28E, F ).

A very large (54.0 × 69.0 mm) male specimen from southwestern India identified as C. verdensis by Selvaraj & Kathirvel (1980: 159, figs 1, 2) is clearly not this species as presently defined. Carcinoplax verdensis does not grow to such a large size, and the general carapace facies and G1 structure also do not match. The photograph of the overall habitus is too poor to see distinguishing characters and it probably belongs to C. indica Doflein, 1904 instead. This species was described from the Andamans and is known to grow to very large sizes. The size of the Indian specimen also argues against it being C. longipes , C. fasciata Ng & Kumar, 2016 , or C. mistio Ng & Mitra, 2019 .

Figures

FIG. 13. — Carcinoplax verdensis Rathbun, 1914, holotype ovigerous ♀ (10.5 × 13.0 mm) (USNM 46167), Philippines: 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, thoracic sternum and pleon; H, sternopleonal cavity and vulvae; I, outer view of right chela; J, outer view of left chela.

FIG. 14. — Carcinoplax verdensis Rathbun, 1914, ♂ (15.7 × 21.4 mm) (ZRC 2019.0549), Philippines: 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, thoracic sternum and pleon; H, outer view of chelae.

FIG. 15. — Carcinoplax verdensis Rathbun, 1914, ♀ (16.3 × 21.9 mm) (ZRC 2019.0546),Philippines: A, overall habitus; B, dorsal view of carapace; C, frontal view of cephalothorax; D, left third maxilliped; E, dorsal view of carpus of right cheliped; F, thoracic sternum and pleon; G, sternopleonal cavity and vulvae.

FIG. 24. — Gonopods: A-D, Carcinoplax verdensis Rathbun, 1914, ♂ (14.9 × 20.2 mm) (ZRC 2019.0547), Philippines; E, F, C. verdensis, ♂ (18.0 × 24.4 mm) (MNHN-B10377), Philippines; G, H, C. verdensis, ♂ (13.0 × 18.0 mm) (MNHN-B10264), Philippines; I, J, C. polita Guinot, 1989, holotype ♂ (15.0 × 19.0 mm) (MNHN-B10141), Philippines; K, C. polita, ♂ (14.5 × 20.0 mm) (ZRC 2000.0173), Philippines; L-O, C. polita, ♂ (25.9 × 30.1 mm) (ZRC 2019.0545), Philippines. A, K, L, left G1 (ventral view); B, M, distal part of left G1 (ventral view); C, N, distal part of left G1 (dorsal view); E, G, I, right G1 (dorsal view); D, J, O, D, L, H, left G2; F, H, J, right G2. E-H, after Guinot (1989: figs 35A, B; 36A, B) (as C. aff. longipes); I, J, after Guinot (1989: fig. 37A, B). Scale bars: A, D, K, L, O, 1.0 mm; B, C, M, N, 0.5 mm; E, F, G, H, not to scale.

FIG. 28. — Colour in life: A, Carcinoplax verdensis Rathbun, 1914, ♂ (16.9 × 23.0 mm) (ZRC 2009.1003), Philippines; B, C. verdensis, ♂ (15.7 × 21.4 mm) (ZRC 2019.0549), Philippines; C, C. verdensis, ♂ (19.2 × 27.7 mm) (ZRC 2019.0555), Philippines; D, C. verdensis, ♀ (5.8 × 8.1 mm) (ZRC 2019.0548), Philippines; E, C. verdensis, ♀ (12.8 × 17.9 mm) (ZRC 2019.0559), Philippines; F, C. verdensis, ♀ (7.9 × 10.9 mm) (ZRC 2019.0560), Philippines; G, 1 ♀ (6.8 × 8.8 mm) (ZRC 2019.0374), South China Sea; H, C. fasciata Ng & Kumar, 2016, holotype ♂ (25.8 × 19.3 mm) (DABFUK), India. Photographs: D-G, T.-Y. Chan; H, B. Kumar.

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.