Geosesarma, De Man, 1892

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 : 245

Key to Species of Javan Geosesarma

1. Dorsal margin of dactylus of male chela with 3 or 4 tubercles; G1 relatively stout...................................................................2

– Dorsal margin of dactylus of male chela with more than 5 tubercles; G1 relatively slender ..............................................3

2. Male pleon with somite 6 trapezoidal ( Fig. 11D, E ); G1 proportionately very stout, wide, chitinous part very short, bent about 45° along longitudinal axis ( Fig. 12 B–F) [Bogor Regency, West Java]....................... G. robustum , new species

– Male pleon with somite 6 subrectangular ( Fig. 8D, E ); G1 proportionately less stout, more narrow, chitinous distal part relatively elongate, bent about 80° along longitudinal axis ( Fig. 10 B–D) [Sukabumi Regency, West Java] ................................ ........................................................ G. sukabumi , new species

3. Dorsal margin of dactylus of male chela with 6 or 7 large tubercles ( Fig. 22 F–H); G1 very short, stout with short, rounded chitinous distal part ( Fig. 23 B–F) [Malang Regency, East Java] ................................................. G. rouxi ( Serène, 1968a)

– Dorsal margin of dactylus of male chela with 7–19 small tubercles along almost entire length; G1 slender, chitinous distal part long, slender to spatulate.......................................4

4. Dorsal margin of dactylus of male chela with 7–13 small tubercles (including small one near tip) along almost entire length; species living from lowlands to about 700 m asl......5

– Dorsal margin of dactylus of male chela with 15–19 small tubercles (including small one near tip) along almost entire length; montane species, from 900 m asl and above.............9

5. Carapace in life distinctly with anterior and posterior halves differently coloured .................................................................6

– In life, carapace evenly coloured grey, brown, orange or purple, the anterior and posterior halves not distinctly separated......7

6. Anterior half of carapace purple to purplish-brown, posterior half cream to yellowish-white ( Ng et al., 2015: fig. 6A–C); dorsal margin of dactylus of male chela with 7–9 small tubercles ( Ng et al., 2015: fig. 5D) [Cilacap Regency, Central Java]............ ........................... G. dennerle Ng, Schubart & Lukhaup, 2015

– Anterior half of carapace bright purple on anterior half, posterior half bluish-grey ( Ng & Davie, 1995: 32); dorsal margin of dactylus of male chela with 10 or 11 small tubercles ( Ng & Davie, 1995: fig. 2D, E; Ng et al., 2015: fig. 5C) [Ujung Kulon, Lebak Regency, Banten] ......... G. bicolor Ng & Davie, 1995

7. Carapace evenly orange throughout in life ( Ng et al., 2015: fig. 6D–F); dorsal margin of dactylus of male chela with with 7–9 small tubercles ( Ng et al., 2015: figs. 5E) [Cilacap Regency, Central Java].......... G. hagen Ng, Schubart & Lukhaup, 2015

– Carapace otherwise coloured in life; dorsal margin of dactylus of male chela with 11–13 or small tubercles (last one often very small) ..............................................................................8

8. Male pleon proportionately broader ( Fig. 1D ); G1 more slender with subdistal part of outer margin more rounded, curved, dorsal section proportionately more slender; chitinous distal part bent 40° along longitudinal axis ( Figs. 4D, E, H, I , 6 D–F) [Bogor and Lebak Regencies; West Java and Banten] ........................ .............................................. G. noduliferum ( De Man, 1892)

– Male pleon proportionately more slender ( Fig. 5D ); G1 relatively stouter, subdistal part of outer margin more angular, dorsal distal section more strongly developed, chitinous distal part bent 45° along longitudinal axis ( Figs. 6G, H , 7B, C ) [Lebak Regency; Banten].................................. G. lebak , new species

9. Ambulatory meri proportionately longer and more slender ( Fig. 16A ); G1 with chitinous part relatively longer, gently bent 30° along longitudinal axis ( Fig. 18B, C, H, I ) [Bogor and Sukabumi Regencies; West Java]...................................... ............................................................... G. sekop , new species

– Ambulatory meri proportionately shorter and stouter; G1 with chitinous part relatively shorter, bent 40° along longitudinal axis.........................................................................................10

10. Margin of frontal lobe distinctly convex ( Fig. 13B ); G1 proportionately stouter, chitinous distal part wider in mesial view ( Fig. 15B, C ) [Cibodas, Cianjur Regency, West Java]... ................................................. G. confertum ( Ortmann, 1894)

– Margin of frontal lobe gently convex to almost truncate ( Figs. 19B , 20A ); G1 relatively more slender, chitinous distal part more slender in mesial view ( Fig. 21B, C ) [ Mount Halimun , Bogor Regency, West Java].............. G. cikaniki , new species

Figures

Fig. 11. Geosesarma robustum, new species, holotype male (9.6 × 9.2 mm) (MZB Cru 4452). 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. 12. Geosesarma robustum, new species, holotype male (9.6 × 9.2 mm) (MZB Cru 4452). A, left third maxilliped; B, left G1 (dorsal view); C, left G1 (ventral view); D, E, left G1 (ventro-mesial view); F, left G1(dorso-mesial view); G, left G2. All structures denuded. Scales: A = 1.0 mm; B–G = 0.5 mm.

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. 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. 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.

Fig. 1. Geosesarma noduliferum (De Man, 1892), male (10.9 × 10.4 mm) (ZRC 2018.0282). 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, outer view of left chela; F, dorsal view of dactylus of left chela.

Fig. 4. Geosesarma noduliferum (De Man, 1892). A, D–G, male (10.9 × 10.4 mm) (ZRC 2018.0282); B, male (12.1 × 11.4 mm) (ZRC 2018.0283); C, H–J, male (12.7 × 11.7 mm) (ZRC 2018.0283). A, left third maxilliped; B, C, male pleonal somite 6 and telson; D, H, left G1 (dorsal view); E, I, left G1 (ventral view); F, J, left G1 (dorso-mesial view); G, left G2. All structures denuded. Scales: A–C = 1.0 mm; D–J = 0.5 mm.

Fig. 6. A–C, Geosesarma lebak, new species, paratype female (12.2 × 10.6 mm) (ZRC 2018.0286); D, G. noduliferum (De Man, 1892), male (11.3 × 10.6 mm) (MZB Cru 4796); E, F, G. noduliferum (De Man, 1892), male (10.9 × 10.2 mm) (MZB Cru 4796); G, H, G. lebak, new species, paratype male (11.2 × 10.8 mm) (ZRC 2018.0285). A, overall dorsal view; B, anterior thoracic sternum, telson and pleonal somites 4–6; C, sternopleonal cavity showing vulvae; D, E, G, left G1 (dorsal view); F, H, distal part of left G1 (dorsal view).

Fig. 5. Geosesarma lebak, new species, holotype male (11.7 × 11.3 mm) (MZB Cru 4563). 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, 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. 7. Geosesarma lebak, new species, holotype male (11.7 × 11.3 mm) (MZB Cru 4563). 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. 16. Geosesarma sekop, new species, holotype male (10.5 × 9.4 mm) (MZB Cru 4455). 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, 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. 18. Geosesarma sekop, new species. A–G, holotype male (10.5 × 9.4 mm) (MZB Cru 4455); H, I, male (12.1 × 10.8 mm) (MZB Cru 4466). A, right third maxilliped; B, H, left G1 (dorsal view); C, I, left G1 (ventral view); D, E, left G1 (ventro-mesial view); F, left G1(dorso-mesial views); G, right G2. All structures denuded. Scales: A, H, I = 1.0 mm; B–G = 0.5 mm.

Fig. 13. Geosesarma confertum (Ortmann, 1894), male (9.3 × 8.6 mm) (MZB Cru 4797). A, overall dorsal view; B, dorsal view of carapace; C, frontal view of cephalothorax; D, propodus and dactylus of left first ambulatory leg; E, outer view of right chela; F, dorsal view of dactylus right chela; G, anterior thoracic sternum, telson and pleonal somites 4–6; H, posterior thoracic sternum and pleonal somites 2–6.

Fig. 15. Geosesarma confertum (Ortmann, 1894), male (9.3 × 8.6 mm) (MZB Cru 4797). A, left third maxilliped (distal part of flagellum broken off); B, left G1 (dorsal view); C, left G1 (ventral view); D, left G1 (dorso-mesial view); E, left G1(ventro-mesial view); F, left G2. All structures denuded. Scales = 0.5 mm.

Fig. 19. Geosesarma cikaniki, new species, holotype male (8.9 × 8.7 mm) (MZB Cru 4649). 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, outer view of left chela; F, dorsal view of dactylus of left chela.

Fig. 20. Geosesarma cikaniki, new species. A–C, paratype male (11.9 × 11.0 mm) (MZB Cru 4650); D–F, paratype female (9.9 × 8.9 mm) (MZB Cru 4619). A, D, overall dorsal view; B, E, anterior thoracic sternum, telson and pleonal somites 4–6; C, dorsal margin of dactylus of right chela; F, sternopleonal cavity showing vulvae

Fig. 21. Geosesarma cikaniki, new species, holotype male (8.9 × 8.7 mm) (MZB Cru 4649). A, left third maxilliped; B, left G1 (dorsal view); C, left G1 (ventral view); D, left G1(dorso-mesial views); E, left G2. All structures denuded. Scales = 0.5 mm.