Geosesarma sukabumi, Ng & Wowor, 2019

Ng, Peter K. L. & Wowor, Daisy, 2019, The vampire crabs of Java, with descriptions of five new species from Mount Halimun Salak National Park, West Java, Indonesia (Crustacea: Brachyura: Sesarmidae: Geosesarma), Raffles Bulletin of Zoology 67, pp. 217-246 : 227-228

Geosesarma sukabumi , new species

( Figs. 8–10 )

Material examined. West Java Province, Sukabumi Regency: holotype: male (11.5 × 10.3 mm) ( MZB Cru 4555), Cikakak District , Ds. Cirendang, Kp. Paniisan, cliff nearby S. Cirendang, 06°53′57.0″S 106°33′11.1″E, 587 m asl, coll. D. Wowor et al., 18 May 2016. Paratypes: 13 males (6.3 × 5.5 mm – 10.5 × 9. 1 mm), 8 females (5.2 × 4.7 mm – 10.4 × 9.9 mm), 2 juveniles ( MZB Cru 4647), 1 male (10.3 × 9.0 mm), 1 female (9.2 × 8.0 mm) ( ZRC 2018.0287 ex-MZB Cru 4647), same data as holotype .

Diagnosis of male. Carapace subquadrate, slightly wider than long, lateral margins sinuous, gently divergent ( Fig. 8A, B ); dorsal surface with clear regions, anterior regions with numerous small rounded granules ( Fig. 8B, C ); front deflexed, frontal lobes broad with convex margins, separated by broad, shallow median concavity; postfrontal cristae sharp ( Fig. 8B, C ); external orbital tooth triangular, directed obliquely outwards, tip extending slightly beyond anterior part of lateral carapace margin, first epibranchial tooth truncate, well defined, separated from margin by small cleft ( Fig. 8B ). Ischium of third maxilliped ovate; exopod relatively slender, with long flagellum that extends just beyond merus width ( Fig. 10A ). Outer surface of palm of adult male chelae with low granules and rugae; inner surface granulated but without transverse comb-like ridge; dorsal margin of dactylus with 3 or 4 distinct large tubercles on proximal third, each with chitinous tip ( Fig. 8 F–H). Ambulatory legs with relatively broad meri, with sharp subdistal spine on dorsal margin, surfaces rugose; ventral margins of propodus and dactylus of adult first ambulatory leg with dense comb-like setae. Male pleon triangular; telson triangular with rounded tip, as long as broad; somite 6 wide, with convex lateral margins ( Fig. 8D, E ). G1 relatively stout, subdistal part of outer margin before chitinous distal part gently curved with inner dorsal section strongly developed; chitinous distal part bent about 80º along longitudinal axis, tapering, relatively slender in lateral view, spatuliform in mesial view; tip rounded when viewed dorsally ( Fig. 10 B–E).

Females. The adult female carapace is more trapezoidal in form ( Fig. 9A ). The vulvae are on the anterior half of sternite 6, slightly raised, directed obliquely inwards towards the median line of the sternum, the margin is indented medially and without a sternal opercular cover ( Fig. 9C ).

Etymology. The species is named after the region where it was found, Sukabumi Regency. The name is used as a noun in apposition.

Remarks. See General Discussion for comparisons with allied Javan species.

Notes on habitat. The species was found under wet leaf litter, with water seeping from the base of a cliff, not far from a stream at the edge of a small hamlet. The ground is a mixture of gravel and coarse sand. The habitat is about 12.6 m above the stream, shadowed by trees grow on the cliff at around 580 m asl ( Fig. 25C ).

Life colouration. The carapace and chelae are dark brown with black eyes.

Distribution. Sukabumi Regency in West Java Province, in Gunung Koneng Resort of Mount Halimun Salak National Park.

Figures

Fig. 8. Geosesarma sukabumi, new species, holotype male (11.5 × 10.3 mm) (MZB Cru 4555). A, overall dorsal view; B, dorsal view of carapace; C, frontal view of cephalothorax; D, anterior thoracic sternum, telson and pleonal somites 5 and 6; E, anterior thoracic sternum, telson and pleonal somites 3–6; F, outer view of right chela; G, dorsal view of right chela; H, dorsal view of dactylus of right chela.

Fig. 9. Geosesarma sukabumi, new species, paratype female (10.3 × 9.2 mm) (MZB Cru 4647). A, overall dorsal view; B, anterior thoracic sternum, telson and pleonal somites 4–6; C, sternopleonal cavity showing vulvae.

Fig. 10. Geosesarma sukabumi, new species, holotype male (11.5 × 10.3 mm) (MZB Cru 4555). A, left third maxilliped; B, left G1 (dorsal view); C, left G1 (ventral view); D, left G1 (ventro-mesial view); E, left G1(dorso-mesial view); F, left G2. All structures denuded. Scales: A = 1.0 mm; B–F = 0.5 mm.

Fig. 25. Habitats. A, Geosesarma noduliferum habitat, stream at Tenjolaya District, Bogor Regency; B, G. lebak, new species, edge of S. Cimaja in Banten Province; C, G. sukabumi, new species, cliff face above S. Cirendang, Sukabumi Regency; D, G. robustum, new species, head water of S. Ciampea, Bogor Regency; E, G. cikaniki, new species, moist forest in Cikaniki Research Station, Bogor Regency.