Geosesarma rouxi ( Serène, 1968a )

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 : 240-243

Geosesarma rouxi ( Serène, 1968a)

( Figs. 22 , 23 )

Sesarma (Sesarma) sylvicola – Roux, 1933: 11. (not Sesarma sylvicola De Man, 1892 )

Sesarma (Geosesarma) rouxi Serène, 1968a: 1092 , text fig. 15, 16, pl. 2 fig. 4; Serène, 1968b: 107.

Geosesarma rouxi – Ng et al., 2008: 221.

Material examined. East Java Province, Malang Regency: paratypes: 2 males (10.0 × 9.5 mm, 12.6 × 12.3 mm) ( ZRC 2014.0358 ), Poedjon (= present day Pujon), cascades, ca. 7°50′37″S 112°28′08″E, Pujon District , East Java, Indonesia, coll. J. Roux, 16 January 1929 .

Diagnosis of male. Carapace quadrate, slightly wider than long, lateral margins gently convex, subparallel ( Figs. 22A, B ); dorsal surface with regions, anterior regions with small flattened granules ( Figs. 22B ); front deflexed, frontal lobes broad with convex margins, separated by median concavity; postfrontal cristae relatively sharp ( Figs. 22B, C ); external orbital tooth triangular, directed obliquely anteriorly, tip not extending beyond anterior part of lateral carapace margin, first epibranchial tooth low but distinct, separated from margin by distinct cleft ( Figs. 22B ). Ischium of third maxilliped short, ovate, wide; exopod relatively slender, with long flagellum that extends across width of merus ( Fig. 23A ). Outer surface of palm of adult male chelae with spaced out granules; inner surface granulated but without transverse comb-like ridge; dorsal margin of dactylus with 6 or 7 large tubercles, each with chitinous tip along most of length except distal part ( Figs. 22 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 broadly triangular; telson triangular with rounded tip, as long as broad; somite 6 wide with convex lateral margins ( Figs. 22D, E ). G1 short, stout, subdistal part of outer margin before chitinous distal part angular; chitinous distal genty bent, short, round, subtruncate in lateral view, spatulate in mesial and dorsal views ( Fig. 23 B–F).

Females. Not known.

Remarks. Roux (1933: 11) had reported this taxon as Sesarma sylvicola De Man, 1892 , listing 22 males and 11 females among his collection. Serène (1968a: 1092) argued it was not De Man’s species and described it as new from seven males he had on hand: the holotype (11.0 × 11.5 mm), four males which he labelled A–D (10.0 × 10.5 mm, 11.5 × 12.0 m, 9.0 × 9.5 mm, 12.0 × 12.5 mm, respectively) and two juveniles. The present two specimens in the ZRC have a small label C and D each, respectively, and are clearly the two paratypes listed by him. The type locality was stated to be “Poedjon (Cascade), (Centre Java, Indonesie)” ( Serène, 1968a: 1093), but this is not correct as this location is actually in East Java, in the highlands northwest of Malang. The altitude of Pujon is around 1,100 m asl.

See General Discussion for comparisons with allied Javan species.

Notes on habitat. Not known.

Life colouration. Not known.

Distribution. Known only from the type locality.

Figures

Fig. 22. Geosesarma rouxi (Serène, 1968a), male (12.6 × 12.3 mm) (ZRC 2014.358). A, overall dorsal view; B, dorsal view of carapace; C, frontal view of cephalothorax; D, anterior thoracic sternum, telson and pleonal somites 4–6; E, posterior thoracic sternum and pleonal somites 1–6; F, outer view of right chela; G, H, dorsal view of dactylus of right chela (different angles).

Fig. 23. Geosesarma rouxi (Serène, 1968a), male (12.6 × 12.3 mm) (ZRC 2014.358). A, left third maxilliped; B, left G1 (dorsal view); C, left G1 (ventral view); D, E, left G1 (ventro-mesial views); F, left G1 (dorso-mesial view); G, left G2. All structures denuded. Scales: A = 1.0 mm; B–G = 0.5 mm.