Geosesarma bicolor Ng & Davie, 1995

Ng, Peter K. L., Schubart, Christoph D. & Lukhaup, Christian, 2015, New species of “ vampire crabs ” (Geosesarma De Man, 1892) from central Java, Indonesia, and the identity of Sesarma (Geosesarma) nodulifera De Man, 1892 (Crustacea, Brachyura, Thoracotremata, Sesarmidae), Raffles Bulletin of Zoology 63, pp. 3-13 : 6

Geosesarma bicolor Ng & Davie, 1995

( Figs. 1C, D , 2 F–J, 5C)

Geosesarma bicolor Ng & Davie, 1995: 31 , figs. 1, 2; Ng et al., 2008: 220.

Material examined. Holotype: male (11.0 × 10.5 mm) ( ZRC 1995.279 ), Citerjun, in creeks, under stones, Ujung Kulon, West Java, coll. C. Stewart, July 1993 . Paratypes: 1 male (10.5 × 9.9 mm), 2 nonovigerous females (10.0 × 9.7 mm, 13.9 × 12.7 mm) (both mature) ( ZRC 1995.280 ), same data as holotype .

Diagnosis. Carapace squarish, slightly wider than long, lateral margins subparallel ( Fig. 1C, D ); dorsal surface with well-defined regions, anterior regions covered with numerous small rounded granules ( Fig. 1C, D ); front deflexed, frontal lobes very broad with convex margins; postfrontal cristae prominent ( Fig. 1C, D ); external orbital tooth triangular, directed obliquely outwards, tip level with lateral carapace margin ( Fig. 1C ). Exopod of third maxilliped relatively slender, with long flagellum that extends beyond merus width. Outer surface of palm of adult male chelae granulated; dorsal margin of dactylus with 10 or 11 tubercles, each with pectinated tip ( Fig. 5C ). Ambulatory legs with relatively broad meri, with sharp subdistal spine on dorsal margin, surfaces rugose ( Fig. 1C ). Male abdomen relatively broad; telson triangular with rounded tip, longer than broad; somite 6 with convex lateral margins ( Fig. 2J ). G1 slender, proximal part gently curved, distal part pectinated, bent, elongate, subspatuliform; tip entire, subtruncate when viewed dorsally ( Fig. 2 F–I).

Colour. In life, the species is bright purple on the anterior third of the carapace and ambulatory legs; with the posterior parts of the carapace bluish-grey; the chelae red and eyes bright yellow [cf. Ng & Davie, 1995: 32].

Remarks. The species is re-diagnosed here and the important G1 and male abdominal structures refigured to allow for more accurate comparisons with the two new species (see general discussion).

Figures

Fig. 1. A, B, Geosesarma noduliferum (De Man, 1892), lectotype male (11.4 × 10.9 mm) (RMNH 1246a), Bogor, Java; C, D, G. bicolor Ng & Davie, 1995, holotype male (11.0 × 10.5 mm) (ZRC 1995.279), Ujung Kulon, Java; E, F, G. confertum (Ortmann, 1894), male (10.7 × 9.7 mm) (ZRC 1970.3.7.11), Tjibodas, Java. A, C, E, overall view; B, D, F, dorsal view of carapace.

Fig. 2. A–E, Geosesarma noduliferum (De Man, 1892), lectotype male (11.4 × 10.9 mm) (RMNH 1246a), Bogor, Java; F–J, G. bicolor Ng & Davie, 1995, holotype male (11.0 × 10.5 mm) (ZRC 1995.279), Ujung Kulon, Java. A–C, F–I, left G1 (drawn from different angles); D, left G2; E, male abdominal somites 2–6 and telson; J, male abdominal somites 3–6 and telson. All structures denuded. Scale bars = 1.0 mm.

Fig. 5. A, B, Geosesarma noduliferum (De Man, 1892), lectotype male (11.4 × 10.9 mm) (RMNH 1246a), Bogor, Java; C, G. bicolor Ng & Davie, 1995, holotype male (11.0 × 10.5 mm) (ZRC 1995.279), Ujung Kulon, Java; D, F, G. dennerle, new species, holotype male (14.4 × 14.0 mm) (MZB 4061), Cilacap, Java; E, G, G. hagen, new species, holotype male (13.9 × 13.3 mm) (MZB 4062), Cilacap, Java; H, I, G. confertum (Ortmann, 1894), male (10.7 × 9.7 mm) (ZRC 1970.3.7.11), Tjibodas, Java. A, H, anterior male thoracic sternum and abdomen; B–E, I, outer surface of right chela; F, G, left last ambulatory leg