Carcinoplax polita Guinot, 1989: 298 Ng et al. 2008: 80 Carcinoplax specularis Castro 2007: 640 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) Ng, Peter K. L. Castro, Peter Zoosystema 2020 2020-06-09 42 17 239 284  Castro 2007: 640  7TCVM Guinot, 1989 Guinot 1989 [274,633,216,243] Malacostraca Goneplacidae Carcinoplax Animalia Decapoda 28 265 Arthropoda species polita  ( Figs 16A-H; 17A-I; 24I-O; 27G, H)      Carcinoplax polita Guinot, 1989: 298, figs 24, 37, pl. 8, figs E-H [ typelocality: southern Luzon, Philippines]. —  Ng et al.2008: 80[in list].    Carcinoplax specularis[part] –  Castro 2007: 640[ Taiwan, Philippines].   TYPE MATERIAL. —  Holotype.  South China Sea• ♂, 14.5 × 20.4 mm; MUSORSTOM 1, stn CP31; MNHN-IU-2008-10565 (= MNHN-B10140); allotype ♀, 12.5 × 16.9 mm; MNHN-IU-2008-10584 (= MNHN-B10543); paratype ♂, 9.2 × 12.2 mm; MNHN-IU-2008-10571 (= MNHN-B10268).   TYPELOCALITY. — South ChinaSea, Philippines, southern Luzon, 187- 195 m.  MATERIAL EXAMINED. — South ChinaSea•  1 ♀, 8.8 × 12.7 mm; NANHAI 2014, stn CP4116; 20°02.3211’N, 114°10.2157’E;  262-298 mdepth;  11.I.2014; ZRC 2018.1428•  1 ♀, 9.8 × 13.9 mm; DONGSHA 2014, stn CP4128, Dongsha Is, 20°44.857’N, 116°08.01’E;  420-444 mdepth;  1.V.2014; ZRC 2018.1429.    Philippines• 1 ♀, 8.7 × 12.4 mm; Bohol, Balicasag I., off Panglao I.; tangle nets of local fishermen; 9°31’00.2”N, 123°40’50.5”E;  2-700 mdepth;.  XII.2000; ZRC 2019.0565•  2 ♂, 13.6 × 18.9 mm, 15.0 × 19.4 mm; same location as ZRC 2019.0565;  200-300 mdepth;.  I.2004; ZRC 2004.0805•  1 ♂, 25-30; same location as ZRC 2019.0565;.  VII.2006; ZRC 2019.0567ex ZRC 2004.0730(part)•  4 ♀, 11.6 ×15.6 to 16.0 × 22.4 mm, 5 ♂, 14.1 × 20.0 mm to 15.0 × 20.9 mm; same location as ZRC 2019.0565;  50-500 mdepth;  2.III.2004; ZRC 2004.0727• 1 ovigerous ♀, 15.4 × 21.4 mm, 1 ♀, 5 ♂, largest 17.8 × 24.5 mm; same location as ZRC 2019.0565;  50-500 mdepth;  28.XI.2001; ZRC 2001.0540•  1 ♀, 2 ♂; same location as ZRC 2019.0565;  50-500 mdepth; 25-30 July.2006; ZRC 2019.0566, ex ZRC 2001.0845(part)•  2 ♀, 2 ♂; same location as ZRC 2019.0565; coll. M. Takeda& H. Komatsu,  II.2003; NSMT-Cr 15365•  1 ♀, 12.8 × 17.8 mm; PANGLAO 2004, stn P1, tangle nets of local fishermen; 09°36’S, 123°45’E,  90-200 mdepth; ZRC 2006.017•  1 ♂, 14.5 × 20.0 mm; PANGLAO 2004, stn P4, 09°31’00.2”N, 123°40’50.5”E, tangle nets of local fishermen;  8.VI.2004; ZRC 2006.0173•  1 ♂, 25.9 × 30.1 mm; AURORA2007, stn CP2709, Luzon Sea; 15°11.07’N, 121°34.72’E- 15°12.36’N, 121°34.02’E;  244-296 mdepth;  28.V.2007; ZRC 2019.0545.    Indonesia. 1 ♂, 6.5 × 7.9 mm; SJADES, stn CP34, E. Indian Ocean; 07°44.464’S, 107°39.018’E;  234-243 mdepth;  29.III.2018; ZRC2018.1417.  DIAGNOSIS. — Carapace ( Figs 16A, B; 17A, B, E; 27G, H) quadrate, slightly wider than long (1.4 × wider than long in holotype); slightly convex, marked by two distinct transverse elevations across cardiac, gastric regions. Front ( Figs 16H; 17B, C, F) straight, no notch between front, inner edge of supraorbital border (slight notch in some specimens). Rounded, short tooth on outer orbital angle; margin between outer orbital tooth, anterolateral teeth distinctly granular; two slender, acute-tipped anterolateral teeth on each side of carapace, second tooth curved. Large, high granules on subhepatic, pterygostomial regions ( Figs 16C; 17B, C, F), particularly pronounced in pterygostomial crest, ridge; short granules on anterior (sometimes throughout) dorsal surface of carapace. Posterior margin of epistome ( Fig. 17B, C, F) straight, notch on each lateral margin absent or slight. Distal fourth of fingers dark brown in females ( Fig. 17D, I), males ( Fig. 16A, H). “Window” not observed on cheliped propodi. Inner (ventral), distal margin of cheliped carpus ( Fig. 16E, F) with acute, curved, triangular tooth typically accompanied by tooth-like tubercles along margin of carpus; outer, proximal margin with short tooth. P2-P5 ( Figs 16A; 17D; 27G, H) moderately stout in appearance, P5 barely reaching tip of second anterolateral tooth. Malepleon proportionally narrow ( Fig. 16G). G1 ( Fig. 24I, K, L-N; Guinot 1989: fig. 37A) slender, subconical, with tapering tip, sometimes elongated; scattered spinules; G2 ( Fig. 24J, O; Guinot 1989: fig. 37B) slender, nearly equal or slightly longer than G1, straight flagellum, tip with two lateral spinules. COLOUR IN LIFE. — Colours of the two photographed individuals ( Fig. 27G, H) varies from orange to bright red-orange. Legs (P2-P5) are orange to red-orange with white proximal and distal portions.  GEOGRAPHICAL DISTRIBUTION. — Taiwan, South ChinaSea, Philippines, and Indonesia(southern Java). DEPTH. — Present in samples collected at depths of 200- 700 m.  REMARKS The carapaces of two species (  C. politaand  C. jugum n. sp.) are distinctive in that the gastric and cardiac regions are distinctively more swollen laterally, so much so that the dorsal surface appears gently corrugated, with a shallow but distinct transverse furrow between the regions ( Figs 16A, B; 17A, B, E; 27G, H). This is particularly obvious when the surface is dried. While there is also a shallow groove between the gastric and cardiac regions in the other species, the conditions in  C. politaand  C. jugum n. sp.are unusual in that the groove is distinctly wider and more prominent. The chelipeds of these two species are also distinctive in that only the distal third or half of the fingers are pigmented, even in juveniles.  Carcinoplax politais a very distinctive taxon in that it is the only member of this group of species that has an additional spine on the outer surface of the carpus of the cheliped ( Fig. 16E). All other species, including  C. jugum n. sp., has a smooth and unarmed outer margin. The spine is always present, even if eroded, and occurs even in small specimens and females. In addition to the structure of the cheliped carpal spines,  C. politais easily separated from  C. jugum n. sp.in that the margins between the outer orbital tooth and the anterolateral teeth are distinctly granular ( Fig. 17F) (margins appear smooth in  C. jugum n. sp.; Fig. 21C); the dorsal surface of the carapace is gently convex in frontal view ( Figs 16C; 17B, F) (more prominently inflated in  C. jugum n. sp.; Figs 21C; 22C); the posterior margin of the epistome with a prominent triangular median lobe and strongly concave lateral margins ( Fig. 17B, C, F) (median lobe more obtuse, lower and the lateral margins distinctively v-shaped in  C. jugum n. sp.; Figs 21D; 22D); possessing a proportionally wider male pleon ( Fig. 16G) than in  C. jugum n. sp.( Fig. 21H), and most significantly, the G1 has the distal part subconical in form with the tip tapering, sometimes elongated, and directed obliquely laterally ( Fig. 24I, K, L-N) (the distal part is more dilated, resembling a bird’s head with the tip never elongated and directed upwards in  C. jugum n. sp.; Fig. 25Q-S).  FIG. 16. —  Carcinoplax polita Guinot, 1989, ♂ (15.7 × 22.4 mm) (ZRC 2004.0727), Philippines: A, overall habitus; B, dorsal view of carapace; C, frontal view of cephalothorax; D, left third maxilliped; E, thoracic sternum and pleon; F, dorsal view of carpus of left cheliped; G, dorsal view of carpus of right cheliped; H, outer view of chelae.  FIG. 17. —  Carcinoplax polita Guinot,1989: A -C, ♂ (15.2 × 20.5 mm) (ZRC 2004.0727),Philippines; D -I, ♀ (15.3 × 21.1 mm) (ZRC 2004.0727),Philippines; A, E, dorsal view of carapace; B, F, frontal view of cephalothorax; C, posterior margin of epistome; D, overall habitus; G, thoracic sternum and pleon; H, sternopleonal cavity and vulvae; I, outer view of chelae. Small but adult specimens of  C. polita( 15-18 mmCL), including the holotype, have a G1 which is gently sinuous, with the distal part subconical in form and the tip tapering but short ( Fig. 24I, K). In a very large specimen of  C. polita(25.9 × 30.1 mm, ZRC 2019.0545), the overall G1 is proportionately more slender than in smaller specimens, with the tip of the distal part prominently more elongated ( Fig. 24L- N). This specimen, however, agrees in all other aspects with typical  C. polita, although that it has relatively larger granules on the carapace surface. These differences are likely to be associated with its large size. 2636192376 MNHN- China South Sea 28 265 MNHN-B10543, MNHN-B10268 3 1 2 holotype 2636192443 2014-01-11 ZRC 280 20.038685 1 114.170265 28 265 ZRC 2018.1428 1 1 2636192358 2014-05-01 ZRC 432 20.747616 8 116.1335 28 265 ZRC 2018.1429 1 1 2636192419 2000-12 ZRC Balicasag I. & Panglao I. Philippines 351 9.516722 Bohol 1 123.680695 28 265 ZRC 2019.0565 1 1 Bohol 2636192315 2004-01 ZRC Balicasag I. & Panglao I. Philippines 250 9.516722 Bohol 1 123.680695 28 265 ZRC 2004.0805 2 2 Bohol 2636192400 2006-07 ZRC Balicasag I. & Panglao I. Philippines 250 9.516722 Bohol 1 123.680695 28 265 ZRC 2019.0567, ZRC 2004.0730 1 1 Bohol 2636192303 2004-03-02 ZRC Balicasag I. & Panglao I. Philippines 275 9.516722 Bohol 1 123.680695 28 265 ZRC 2004.0727 9 4 5 Bohol 2636192439 2001-11-28 ZRC Balicasag I. & Panglao I. Philippines 275 9.516722 Bohol 1 123.680695 28 265 ZRC 2001.0540 7 2 5 Bohol 2636192445 2001-11-28 ZRC July. Philippines 275 9.516722 Bohol 1 123.680695 28 265 ZRC 2019.0566, ZRC 2001.0845 3 1 2 Bohol 2636192318 2003-02 ZRC M. Takeda & H. Komatsu Philippines 275 9.516722 Bohol 1 123.680695 28 265 4 2 2 Bohol 2636192377 ZRC Philippines 145 -9.6 1299 123.75 28 265 ZRC 2006.017 1 1 2636192453 2004-06-08 ZRC Philippines 9.516722 1 123.680695 28 265 ZRC 2006.0173 1 1 2636192370 2007-05-28 ZRC Philippines 270 15.206 Luzon Sea 13 121.567 28 265 ZRC 2019.0545 1 1 Aurora 2636192346 2018-03-29 ZRC E. Indian Ocean Indonesia 238 -7.741067 Indonesia 1 107.6503 28 265 1 1