Ceratoplax fulgida Rathbun, 1914

Ng, Peter K. L. & Clark, Paul F., 2015, Ceratoplax margarita n. sp., a new rhizopine crab (Crustacea: Brachyura: Pilumnidae) from Papua New Guinea, with rediagnoses of C. truncatifrons Rathbun, 1914, and C. fulgida Rathbun, 1914, Zoosystema 37 (2), pp. 323-331 : 325-327

Ceratoplax fulgida Rathbun, 1914

( Figs 3 ; 4 D-I) Ceratoplax fulgida Rathbun, 1914: 146 . — Tesch 1918: 55 (key); Serène 1968: 91 (list). — Ng 1987: 78, 88 (discussion). — Ng et al. 2008: 143 (list).

TYPE MATERIAL. — Holotype: Near Marinduque Island, ♂, 7.1 × 4.3 mm, ( USNM 46401). Paratype: 1 ♀, 6.3 × 4.1 mm, ( USNM 46401), stn 5371, near Marinduque Island: Tayabas Light (outer), north 43° west, 6 miles, 13°49’40”N, 121°40’15”E, 83 fms, coll. R. V. Albatross, 24.II.1909.

DIAGNOSIS. — Carapace transversely subovate, width 1.54-1.65 × length; dorsal surfaces smooth, glabrous, regions poorly demarcated, H-shaped gastric grooves barely discernible; anterolateral margin strongly convex, entire to weakly dentate with three small clefts, reaching along ⅔ of lateral margin, submarginal parts smooth, not clearly demarcated from posterolateral margin; posterolateral margins gently concave, gradually converging to gently convex posterior carapace margin ( Figs 3A ; 4H, I ). Frontal margin weakly divided into two low subtruncate lobes from dorsal view, gently confluent with supraorbital margin; with low external orbital tooth ( Figs 3A ; 4H, I ). Orbit ovate, small, eyes with small cornea, fused to carapace, immovable ( Fig. 3B ). Posterior margin of epistome gently convex, not clearly divided into lobes ( Fig. 3B ). Anteroexternal angle of merus of third maxilliped with rounded auriculiform structure; exopod stout ( Fig. 4G ). Male thoracic sternum wide, sternites 1 and 2 completely fused to form wide triangular structure; separated from fused sternites 3 and 4 by distinct sinuous suture ( Fig. 3C ). Male abdomen T-shaped; somite 6 rectangular, wider than long; telson triangular, elongate, much longer than somite 6 ( Fig. 3C ). Chelipeds stout, carpus with subdentiform inner angle and tuft of setae, outer angle sharp but not spiniform or dentiform; chela stout, fingers shorter than palm ( Fig. 3A, D, E ). Ambulatory legs, long; articles slender, unarmed; dactylus of last leg upcurved ( Fig. 3A ). G1 distinctly sinuous, subdistal part gently merging with tapering tip that is gently bent, opening slender ( Fig. 4 D-F).

TYPE LOCALITY. — Tayabas Light (outer), near Marinduque Island, north 43° west, 6 miles, 13°49’40”N, 121°40’15”E.

DISTRIBUTION. — Known only from the type locality.

REMARKS

The type series for this species (and the only known specimens) is represented by a male and a female, but it is by no means certain both are conspecific. Although the female paratype specimen looks similar to the male holotype, its anterolateral margin has small clefts marking four low and broad lobes ( Fig. 4I ). In the holotype male, the anterolateral margin is entire ( Figs 3A ; 4H ). Whether this is mere variation can only be ascertained with more material. See discussion for Ceratoplax margarita n. sp.

Figures

FIG. 3. — Ceratoplax fulgida Rathbun, 1914, holotype ♂, 7.1 × 4.3 mm (USNM 46401), Philippines: A, overall dorsal view; B, frontal view of carapace; C, anterior thoracic sternum and abdomen; D, outer view of right chela; E, outer view of left chela. Scale bars: 1.0 mm.

FIG. 4. — A-C, Ceratoplax truncatifrons Rathbun, 1914, holotype ♂, 7.0 × 4.2 mm, (USNM 46399), Philippines; D-H, Ceratoplax fulgida Rathbun, 1914, holotype ♂, 7.1 × 4.3 mm, (USNM 46401), Philippines; I, Ceratoplax fulgida, paratype ♀, 6.3 × 4.2 mm, (USNM 46401), Philippines; A, D, ventral views of left G1s; B, E, dorsal views of left G1s; F, ventral view of tip of left G1; C, G, left third maxillipeds (setae denuded); H, I, right side of carapace. Scale bars: A, B, D, E, 0.1 mm; C, G, 0.2 mm; F, 0.05 mm; H, I, 0.5 mm.