Geosesarma noduliferum ( De Man, 1892 )

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 : 3-6

Geosesarma noduliferum ( De Man, 1892)

( Figs. 1A, B , 2 A–E, 5A, B)

Sesarma (Geosesarma) nodulifera De Man, 1892: 342 , pl. 20, fig.

16; Nobili, 1900: 512 (part). Sesarma nodulifera – Ortmann, 1894: 56. Sesarma (Geosesarma) noduliferum – Rathbun, 1910: 309; Serène,

1968a: 106.

Sesarma (Sesarma) nodulifera – De Man, 1902: 519; Tesch, 1917: 178.

Geosesarma noduliferum – Serène & Soh, 1970: 402, 407; Ng, 1988: 119; Ng et al., 2008: 221.

(not Sesarma (Geosesarma) noduliferum – Serène 1968b: 1094, figs. 19, 20 = Geosesarma confertum (Ortmann, 1892)) .

Material examined. Lectotype (here designated): male (11.4 × 10.9 mm) ( RMNH 1246 a), Tjiparidi River , near Kg. Baruh, near Buitenzorg (= Bogor), coll. M. Weber, July– September 1888 . Paralectotypes: 1 male (10.6 × 9.5 mm), 1 female (11.9 × 10.8 mm) ( RMNH 1246 b), same data as lectotype ; 4 males (11.4 × 10.3 mm, 11.8 × 10.4 mm, 11.2 × 10.3 mm, 11.7 × 10.4 mm), 1 female (10.5 × 10.1 mm) ( RMNH 2611 ), same data as lectotype . Other material: 5 females (largest 11.5 × 10.5 mm) ( ZRC 1989.2076 – 2080 ), rice field behind BIOTROP research station, Bogor, west Java, Indonesia, coll. P.K.L. Ng , 1986; 1 female (11.4 × 10.0 mm) ( ZRC 1990.9166 ), on bank of stream, under rock, Botanical Gardens, Bogor, west Java, coll. P.K.L. Ng, 8 August 1985 .

Diagnosis. Carapace squarish, slightly wider than long, lateral margins subparallel ( Fig. 1A, B ); dorsal surface with well-defined regions, anterior regions covered with numerous small rounded granules ( Fig. 1A, B ); front deflexed, frontal lobes very broad with convex margins; postfrontal cristae prominent ( Fig. 1A, B ); external orbital tooth triangular, directed obliquely outwards, tip level with lateral carapace margin ( Fig. 1B ). Exopod of third maxilliped relatively slender, with long flagellum that extends beyond merus width. Outer surface of palm of adult male chela granulated; dorsal margin of dactylus with 11–13 tubercles, each tubercle with pectinated tip ( Fig. 5B ). Ambulatory legs with relatively broad meri, with sharp subdistal spine on dorsal margin, surfaces rugose ( Fig. 1A ). Male abdomen relatively slender; telson triangular with rounded tip, longer than broad; somite 6 with gently convex lateral margins ( Figs. 2E , 5A ). G1 slender, proximal part gently curved, distal part pectinated, bent, elongate, spatuliform, tip with shallow indentation when viewed dorsally ( Fig. 2 A–C).

Colour. Adult coloration in life not known.

Remarks. The identity of G. noduliferum needs to be clarified. The species was described as Sesarma (Geosesarma) nodulifera from 61 specimens from Tjiparidi River in Kampung Baruh in Bogor, Java. Although De Man (1892: pl. 20 fig. 16) provided very good figures of the carapace, chelipeds and male abdomen, the diagnostic G1 structure was not illustrated. The significance of the G1 for the taxonomy of Geosesarma only became apparent much later, when Serène (1968b) demonstrated that many taxa have characteristic species-diagnostic structures. De Man (1892: 345) commented that he had many specimens from Tjipanas (= present day Cipanas) and Tjibodas (= present day Gunung Gede) in west Java that he could not identify with confidence with G. noduliferum because of their small size and having more tubercles on the movable dactylus of the chela. Ortmann (1894: 56) had several specimens from Tjibodas and also noted that his specimens had more closely packed tubercles on the dactylar finger. As such, he established a new taxon, Sesarma nodulifera var. conferta for them, probably alluding to the greater density of dactylar tubercles. No figures or detailed descriptions were provided. Serène (1968a: 106) synonymised Sesarma nodulifera var. conferta Ortmann, 1894 , with G. noduliferum without comment; and did not use the name again in his later works. Ng et al. (2008: 220) resurrected the name as Geosesarma confertum , but did not elaborate on the reasons why.

Serène (1968b: 1094, figs. 19, 20) provided a figure of the G1 of what he identified as G. noduliferum (as Sesarma ( Geosesarma )) from Tjibodas in West Java. The specimens he examined are in the ZRC [2 males (9.4 × 8.5 mm, 10.7 × 9.7 mm) (ZRC 1970.3.7.11–12), Tjibodas, west Java, don. Bogor Museum, 1960s]. The G1 figured by Serène (1968b: figs. 19, 20) is relatively short and stout with a cylindrical distal part and a rounded tip, and is very different from that of the types of G. noduliferum s. str. in RMNH ( Fig. 2 A–C) from Bogor. As noted by De Man (1892) and Ortmann (1894), the tubercles on the dactylar fingers of the chelae of the Tjibodas males are more numerous (15 or 16) and closely packed on the proximal part ( Fig. 5I ) than those of G. noduliferum s. str. from Bogor (with 11–13 more widely spaced ones, Fig. 5B ). In addition, the carapaces of the Tjibodas’ specimens have a different shape from the Bogor ones, with the lateral margins almost parallel ( Fig. 1E, F ) rather than gently divergent ( Fig. 1A, B ), and the male abdomen (notably somites 5 and 6) being proportionately broader ( Figs. 5H ) (versus narrower, Figs. 2E , 5A ). It is clear that the Tjibodas and Bogor specimens belong to separate species, and G. confertum ( Ortmann, 1894) is a good species and not synonymous with G. noduliferum ( De Man, 1892) s. str., as proposed by Serène (1968a). Tjibodas lies at a much higher altitude than Bogor (2500 m against 300 m above sea level), and species of Geosesarma from highlands and lower altitudes usually belong to separate species (see Ng, 1988; Schubart & Ng, 2014). The identity of De Man’s (1892) material from Tjipanas, which is located in the lowlands east of Tjibodas, will need to be checked; they are probably not G. confertum . Nobili’s (1900) and Rathbun’s (1910) records included material from Bogor and Tjibodas, so both G. noduliferum and G. confertum are represented. The taxonomy of G. confertum , G. rouxi and other highland species from Java is now being studied by the first author and Daisy Wowor (MZB).

In the RMNH are two lots of type specimens of Sesarma (Geosesarma) nodulifera De Man, 1892 , with the same collection data. A male measuring 11.4 × 10.9 mm (RMNH 1246a) is here selected as the lectotype of the species ( Fig. 1A, B ).

For differences between G. noduliferum and the two new species described from central Java, 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