Gordonopsis mazupo, Ng & Liu, 2024

Ng, Peter K. L. & Liu, Xinming, 2024, A new species of the deep-sea porter crab genus Gordonopsis Guinot & Richer de Forges, 1995 (Crustacea, Decapoda, Brachyura, Homolidae) from the South China Sea, Raffles Bulletin of Zoology 72, pp. 127-134 : 127-134

publication ID	https://doi.org/ 10.26107/RBZ-2024-0011
publication LSID	lsid:zoobank.org:pub:98CD97F3-3051-4FDB-9AEB-E7403B4FD6D6
DOI	https://doi.org/10.5281/zenodo.12173743
persistent identifier	https://treatment.plazi.org/id/1F104FDE-B904-4261-A4A5-221D4CE728EF
taxon LSID	lsid:zoobank.org:act:1F104FDE-B904-4261-A4A5-221D4CE728EF
treatment provided by	Felipe
scientific name	Gordonopsis mazupo
status	sp. nov.

Treatment

Gordonopsis mazupo , new species

( Figs. 1–5 View Fig View Fig View Fig View Fig View Fig )

Material examined. Holotype: male (33.4 × 24.3 mm) (SY353B6), Zhongnan Seamount , South China Sea, 13.93°N 115.41°E, 897 m, R / V Tansuo 2 cruise TS2-5, collected together with a bamboo coral by the HOV Shenhaiyongshi, dive SY353, coll. Yadong Zhou, 20 March 2021. GoogleMaps

Diagnosis. Carapace longitudinally ovate, width to length ratio 0.73, distinctly wider posteriorly than anteriorly; dorsal carapace surface inflated, prominently convex in lateral view; dorsal parts with numerous soft setae, just obscuring surface; lateral parts with denser setae, partially obscuring surface ( Figs. 2A–C View Fig , 3A, C View Fig , 4A, B View Fig ). Rostrum relatively short, triangular, with 2 longer, obliquely directed pseudorostral spines, distinctly longer than rostrum; proepistome triangular with gently convex lateral margins, rounded tip and a low median longitudinal ridge ( Figs. 2A–C View Fig , 3A, C, D View Fig , 4A View Fig ); pseudorostral spines directed anterolaterally at angle of about 30° to median axis ( Figs. 2A, B View Fig , 4A View Fig ). Hepatic region gently inflated, with short but distinct obliquely directed spine ( Figs. 2B, C View Fig , 3A, C, D View Fig , 4A View Fig ); gastric region without spines, each mesogastric region with patch of small granules ( Figs. 2B, C View Fig , 4A View Fig ); latero-posterior tubercle on carapace small, just visible ( Figs. 1B View Fig , 2B View Fig ). Third maxilliped merus elongate with angular external angle, unarmed ( Fig. 3B View Fig ). Chelipeds very long ( Figs. 1A View Fig , 2A View Fig , 3E View Fig ); basis-ischium subquadrate, outer margin with 2 spines, inner margin with 3 spines, dorsal margin with 1 large and 1 small spine ( Fig. 3E View Fig ); merus triangular in cross-section, long, dorsal margin with 6 spines and spinules, and 2 distal spines which bracket chela, outer ventral margin with 8 or 9 spines or spinules, inner ventral margin with 6 or 7 spines or spinules ( Figs. 2A View Fig , 3E View Fig ); carpus longitudinally ovate, distal edge with 1 large spine, outer margin with 4 spines and spinules, inner margin with 1 spine, dorsal surface with shallow longitudinal depression, with 2 spinules ( Fig. 3F, G View Fig ). Ambulatory legs very long; basis-ischium subquadrate, with 4 or 5 sharp spines, one on each corner; P2 merus with 6 spines or spinules on proximal half of dorsal margin (excluding 1 distal spine), ventral margin with 1 spinule on proximal quarter ( Fig. 4C, I View Fig ); P3 merus with 2 spines or spinules on proximal quarter of dorsal margin (excluding 1 distal spine), ventral margin with 1 spinule on proximal quarter ( Fig. 4D, J View Fig ); P4 merus with 1 spine on proximal part of dorsal margin (excluding 1 distal spine), ventral margin with 1 small sharp granule on proximal part, outer surface with 1 strong spine on proximal part ( Fig. 4E, K, L View Fig ); P5 merus slender, unarmed on all margins, reaching distinctly beyond gastric groove when folded anteriorly; carpus long, propodus short, enlarged, forming prominent pseudochela with stout, gently curved dactylus; occlusal margin of fixed finger with 7 spines, that of dactylus with 7 or 8 spines and spinules ( Fig. 4F, G, H View Fig ); outer margins of P2 and P3 coxae with 1 or 2 short sharp spines; that of P4 coxa with 1 short proximal spine ( Fig. 5A, B View Fig ). Telson subtriangular, with proximal part distinctly wider, distal part prominently narrowing to acute tip ( Fig. 4B View Fig ). G1 relatively short, stout, distal part subtruncate with gently convex tip ( Fig. 5C, D, E, G, H View Fig ). G2 stout, tubular, subequal to G1 length, distal portion cup-shaped ( Fig. 5F, I View Fig )

Description of male holotype. Carapace longitudinally ovate, width to length ratio 0.73, distinctly wider posteriorly than anteriorly; dorsal carapace surface prominently convex in lateral view, inflated; regions well-defined, separated by distinct grooves; lateral margins distinctly convex; dorsal parts with numerous soft setae, just obscuring surface; lateral parts with denser setae, partially obscuring surface, relatively denser on hepatic, pterygostomial and suborbital regions ( Figs. 2A–C View Fig , 3A, C View Fig , 4A, B View Fig ). Rostrum relatively short, triangular, sharp, margin cristate, with 2 longer, obliquely directed pseudorostral spines (right one damaged), distinctly longer than rostrum; proepistome triangular with gently convex lateral margins and rounded tip, with a low but distinct median longitudinal ridge ( Figs. 2A–C View Fig , 3C, D View Fig , 4A View Fig ). Supraorbital margin relatively narrow, C-shaped; pseudorostral spines directed anterolaterally at angle of about 30° to median axis ( Figs. 2A, B View Fig , 4A View Fig ). Eyes with short ocular peduncle, cornea prominent; no discernible orbit ( Figs. 2A–C View Fig , 3A, C View Fig , 4A View Fig ). Hepatic region gently inflated, with short but distinct obliquely directed spine ( Figs. 2B, C View Fig , 3A, C, D View Fig , 4A View Fig ). Gastric region without spines, each mesogastric region with patch of small granules ( Figs. 2B, C View Fig , 4A View Fig ). Gastric groove well marked, with distinct ovate gastric fossae just above ( Figs. 2A–C View Fig , 3A, C View Fig , 4A View Fig ). Cardiac region swollen; branchial region inflated, with distinct branchio-cardiac grooves ( Figs. 2A–C View Fig , 3A, C View Fig , 4A View Fig ). Latero-posterior tubercle on carapace small, just visible ( Figs. 1B View Fig , 2B View Fig ). Base of antenna, with strong anteriorly directed spine adjacent to it on pterygostomial region ( Figs. 3A, D View Fig ). Antennal flagellum short, second and third articles thick, setose ( Fig. 3D View Fig ). Epistome subrectangular, posterior margin with median part subtriangular, medially divided by fissure ( Fig. 3D View Fig ).

Third maxilliped pediform, covered with setae but unarmed; ischium rectangular, shorter than merus, with shallow longitudinal shallow groove; merus elongate, subovate, with angular external angle but unarmed, margin uneven and without spines or teeth; palp (carpus, propodus and dactylus) elongate, reaching to proximal margin of ischium ( Fig. 3B View Fig ).

Chelipeds very long ( Figs. 2A View Fig , 3E View Fig ). Basis-ischium subquadrate, outer margin with 2 spines, inner margin with 3 spines, dorsal margin with 1 large and 1 small spine ( Fig. 3E View Fig ); merus triangular in cross-section, long, dorsal margin with 6 spines and spinules, and 2 distal spines which bracket chela, outer ventral margin with 8 or 9 spines or spinules, inner ventral margin with 6 or 7 spines or spinules ( Figs. 2A View Fig , 3E View Fig ); carpus longitudinally ovate, distal edge with 1 large spine, outer margin with 4 spines and spinules, inner margin with 1 spine, dorsal surface with shallow longitudinal depression, with 2 spinules ( Fig. 3F, G View Fig ). Chela relatively stout; outer and inner surfaces of palm gently rugose; fingers long, straight, slender, about half length of palm; cutting edge of dactylus with tooth on proximal third, rest of edge blade-like; cutting edge of fixed finger with 2 basal teeth, rest of edge unarmed ( Fig. 3H, I View Fig ). Coxa with strong basal spine, distal edge with rounded projection, otherwise unarmed ( Fig. 4B View Fig ).

Ambulatory legs very long; carpus laterally compressed, long, unarmed; propodus very long, subequal or just shorter than merus, distal part of ventral margin with sharp stiff setae; dactylus almost straight except for gently curved distal part, ventral margin lined with stiff setae and spinules; basis-ischium subquadrate, with 4 sharp spines, one on each corner (right P4 has 5 spines); P2 merus with 6 spines or spinules on proximal half of dorsal margin (excluding 1 distal spine), ventral margin with 1 spinule on proximal quarter ( Fig. 4C, I View Fig ); P3 merus with 2 spines or spinules on proximal quarter of dorsal margin (excluding 1 distal spine), ventral margin with 1 spinule on proximal quarter ( Fig. 4D, J View Fig ); P4 merus with 1 spine on proximal part of dorsal margin (excluding 1 distal spine), ventral margin with 1 small sharp granule on proximal part, outer surface with 1 strong spine on proximal part ( Fig. 4E, K, L View Fig ); P5 merus slender, unarmed on all margins, reaching distinctly beyond gastric groove when folded anteriorly; carpus long, propodus short, enlarged, forming prominent pseudochela with stout, gently curved dactylus; occlusal margin of fixed finger with 7 spines, that of dactylus with 7 or 8 spines and spinules ( Fig. 4F, G, H View Fig ). Outer margins of P2 and P3 coxae with 1 or 2 short sharp spines; those of P4 coxa with 1 short proximal spine ( Fig. 5A, B View Fig ).

Sternopleonal cavity wide, surface relatively flat ( Fig. 5C View Fig ). Pleon subovate; all somites free, somite 4 widest; telson subtriangular, with proximal part distinctly wider, distal part prominently narrowing to acute tip ( Fig. 4B View Fig ). G1 relatively short, stout, distal part subtruncate with gently convex tip ( Fig. 5C, D, E, G, H View Fig ). G2 stout, tubular, subequal to G1 length, distal portion cup-shaped ( Fig. 5F, I View Fig ).

Colour. Carapace yellowish; ventral surface, chelipeds and ambulatory legs orange ( Fig. 1 View Fig ).

Etymology. The species is named after the Chinese Goddess or Grandmother of the Sea, Mazu. The name is used as a noun in apposition.

Remarks. Gordonopsis mazupo , new species, most closely resembles G. pacifica in the carapace shape and swollen dorsal carapace features ( Fig. 3A, C View Fig ), and both possess a prominent spine on proximal outer surface of P4 ( Fig. 4E, K, L View Fig ). The ambulatory legs (P2–P5) of G. mazupo , however, are much longer than those of G. pacifica (cf. Figs. 2A View Fig , 4C–F View Fig ), with the P5 reaching well beyond the gastric groove of the carapace when folded anteriorly ( Fig. 4A View Fig ). In G. pacifica , the P5 reaches just slightly beyond the gastric groove ( Ng & Richer de Forges, 2020: fig. 16A). In addition, the pseudorostral spines of G. mazupo are much longer than the rostrum ( Fig. 2A, B View Fig ) (versus pseudorostral distinctly shorter in G. pacifica ; cf. Ng & Richer de Forges, 2020: fig. 14A, B); and the distal part of the G1 is slightly longer and more subtruncate in shape ( Fig. 5C–E, G, H View Fig ) (versus distal shorter and sharper in G. pacifica ; Ng & Richer de Forges, 2020; fig. 16B, C, M, N).

The long P2–P5 of G. mazupo is actually closest to the condition in G. hera ; but in this species, the carapace is distinctly less inflated, with the dorsal surface flatter, the pseudorostral spines are set further apart from the rostrum; and the P5 dactylus of the pseudochela is relatively stouter (cf. Ng & Richer de Forges, 2020: figs. 17A, B, 18A, 19H).