Carcinoplax jugum Ng & Castro 2020, n. sp.
Creators: name: Ng, Peter K. L.
name: Castro, Peter
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Goneplacidae
Carcinoplax
Carcinoplax jugum

description: Carcinoplax jugum n. sp.
(Figs 21 A-I; 22 A-J; 25 Q-T)
urn:lsid:zoobank.org:act: AF26AE84-ADE8-4F9A-9A41-BA26DEAFE781
TYPE MATERIAL. — Holotype. Philippines • ♂, 45.5 × 33.6 mm; Philippines; ZRC 2004.0777.
Paratypes. Philippines • 1 ♀, 25.7 × 33.8 mm; Bohol, Balicasag I., off Panglao I., tangle nets of local fishermen; 09°31’00.2”N, 123°40’50.5”E; 28.XI.2001; ZRC 2001.0528 • 1 ♂, 24.2 × 32.8 mm; same location as ZRC 2002.0528; 50-500 m depth; ZRC 2001.0973 • 3 ♀, 23.3 × 31.4 mm, 24.9 × 33.4 mm, 27.0 × 35.7 mm, 3 ♂, 13.8 × 19.6 mm, 13.9 × 19.9 mm, 17.2 × 22.2 mm; same location as ZRC 2002.0528; 25-30.VII.2003; ZRC 2004.0750 • 1 ♀, 4 ♂, largest 35.9 × 48.4 mm, smallest 13.6 × 18.9 mm; same location as ZRC 2002.0528; 25-30. VII.2006; ZRC 2001.0845 • 2 ♀, 23.9 × 30.5, 26.8 × 35.3 mm; same location as ZRC 2002.0528; ZRC 2004.0730 • 6 ♀, largest 31.7 × 41.4 mm; same location as ZRC 2002.0528; 200-300 m depth; ZRC 2002.0655 • 1 ♀, 25.1 × 32.5 mm; PANGLAO 2005, stn CP2343, off Pamilican I.; 09°27.4’N, 123°49.4’E; 273-356 m depth; 23.V.2005; ZRC 2006.0217 • 2 ♂, 38.5 × 50.5, 41.4 × 63.0 mm; Maribohoc Bay; coll. J. Arbasto, VII.2004 to. V.2005; ZRC 2018.1432 • 1 ♀, 26.8 × 35.2 mm, 1 juvenile ♀, 11.0 × 14.2 mm; PANGLAO 2005, stn CP2359, Bohol Sea; 08°49.9’N, 123°34.9’E; 437-476 m depth; 26.V.2005; ZRC 2018.1433 • 1 juvenile ♀, 13.8 × 18.0 mm; PANGLAO 2005: stn CP2406, Maribohoc Bay, 9°40.6’N, 123°46.8’E; 334-387 m depth; 1.VI.2005; ZRC 2018.1434 • 1 ♀, 30.0 × 40.2 mm, 1 ♂, 23.7 × 31.4 mm; PANGLAO 2005, stn PN1, tangle nets; 09°31’00.2”N, 123°40’50.5”E; 29.V.2004; ZRC 2004.0777.
TYPE LOCALITY. — Philippines, Bohol, Balicasag I., off Panglao I.; PANGLAO 2004, stn P4, tangle nets of local fishermen.
DIAGNOSIS. — Carapace (Figs 21A, B; 22A, B) quadrate, slightly wider than long (1.3 × wider than long in holotype); slightly convex, marked by two distinct transverse elevations across cardiac, gastric regions. Front (Figs 21C, D; 22C, D) slightly sinuous, slight oblique notch between front, inner edge of supraorbital border. Conspicuous, salient ocular margins, subocular tooth. Triangular, elevated tooth on outer orbital angle; two slender, acute-tipped anterolateral teeth on each side of carapace. Short granules on subhepatic, pterygostomial regions (Figs 21C, D; 22C, D), becoming more pronounced in pterygostomial crest, ridge. Posterior margin of epistome (Figs 21D; 22D) sinuous, with median salient tip, lateral margins wide, concave. Distal third to half of fingers dark brown in females (Fig. 22I, J), males (21A, I, J). Inner (ventral), distal margin of cheliped carpus (Figs 21F, D; 22F) with long, slender, acute-tipped tooth. P2-P5 long, slender in appearance. Male pleon (Fig. 21H) proportionally narrow. G1 (Fig. 25 Q-S) slender; conspicuously pointed tip; G2 (Fig. 25T) slender, nearly equal or slightly longer than G1, slightly curved flagellum, tip with two lateral spinules.
ETYMOLOGY. — From the Latin jugum for ‘yoke’; in reference to the diagnostic yoke-like, wide, and prominently concave lateral margins of the posterior margin of the epistome. Used as a noun in apposition.
COLOUR IN LIFE. — Not known.
GEOGRAPHICAL DISTRIBUTION. — Philippines.
DEPTH. — Present in samples collected at depths of approximately 50-500 m (273-476 m where depths were more accurately measured).
REMARKS
See Remarks for C. polita.
It is noteworthy that most of the specimens of C. jugum n. sp. collected were obtained from tangle nets set on steep deep-sea cliffs, a habitat which is hard to survey (see Ng et al. 2009; Mendoza et al. 2010). This probably explains the paucity of specimens of this species from trawled material in earlier expeditions to Philippines.
description: Published as part of 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), pp. 239-284 in Zoosystema 42 (17) on pages 272-275, DOI: 10.5252/zoosystema2020v42a17, http://zenodo.org/record/3894945