Contusarma cheirogonum ( Targioni Tozzetti, 1877 )

Schubart, Christoph D. & Ng, Peter K. L., 2020, Revision of the intertidal and semiterrestrial crab genera Chiromantes Gistel, 1848, and Pseudosesarma Serène & Soh, 1970 (Crustacea: Brachyura: Sesarmidae), using morphology and molecular phylogenetics, with the establishment of nine new genera and two new species, Raffles Bulletin of Zoology 68, pp. 891-994 : 958-960

Contusarma cheirogonum ( Targioni Tozzetti, 1877)

( Figs. 23D, G, H , 25I , 28 D, 31 B, C, 32 C, 39 , 44 H, 57 B–H)

Sesarma cheirogona Targioni Tozzetti, 1877: 141–145 , pl. 9, fig. 2a–g.

Sesarma bocourti – De Man, 1880: 28; Miers, 1880: 313; Zehntner, 1894: 182; Tweedie, 1940: 90.

Sesarma (Sesarma) bocourti – Nobili, 1900: 507; Tesch, 1917: 135, figs. 1, 2a; Balss, 1922: 155; Roux, 1933: 13.

Sesarma (Episesarma) bocourti – De Man, 1895: 169.

Pseudosesarma bocourti – Tan & Ng, 1994: 82; Ng, 1995: 200, fig. 14; Ng et al., 2008a: 222; Rademacher & Mengedoht, 2011: 30; Lim & Chua, 2015: 18; Ribero et al., 2020: 3.

Material examined. Neotype (here designated): male (24.5 × 21.5 mm) ( ZRC 1995.225), peat swamp beginning of Ulu Assam trail, Bako National Park, Sarawak, Malaysia. coll. P.K.L. Ng & M. Lateef, 29 June 1994. SARAWAK – 3 males, 1 female ( ZRC 1964.9.28.126–130), Stambak, Saribas, Sarawak, coll. L.K. Charles, 1950; 6 males, 2 females ( ZRC 1964.9.28.131–139), Stambak, Saribas, coll. L.K. Charles, 1950; 1 male (26.3 × 23.0 mm) ( ZRC 1995.226), peat swamp, beginning of Ulu Assam trail, Bako National Park, coll. P.K.L. Ng, 28 June 1994; 2 females ( ZRC 2010.0063), Bako National Park trail, coll. rangers, May 2002. PENINSULAR MALAYSIA – 1 male ( ZRC 1971.9.22.11), Kota Tinggi, Johor, Malaysia, coll. M.W.F. Tweedie, 1940; 5 males, 3 females ( ZRC 1964.9.28.140–149), Kota Tinggi, Johor, coll. M.W.F. Tweedie, 1950; 16 males, 18 females ( ZRC 1964.9.28.150–183), Kota Tinggi, Johor, coll. M.W.F. Tweedie, 1950; 4 males, 3 females ( ZRC 1996.1724), Pulau Tioman, Sungei Ayer Besar, stream along beginning of Tekok Juara trail (Tekek side), coll. P.K.L. Ng et al., 29 June 1996; 1 male ( ZRC 1999.890), Pulau Tioman, Juara tributary of Sungei Keliling, ca 500 m south after Sungei Keliling, coll. H.H. Tan, 18 June 1999; 3 males ( ZRC 1999.611), Pulau Tioman, coll. P.K.L. Ng, 1996; 1 male ( ZRC 1996.1726), Pulau Tioman, Kampung Genting, Sungei Ayer Raja, 2°45′36.7″N 104°07′21″E, coll. P.K.L. Ng et al., 15 September 1995; 3 females, 2 males ( ZRC 2011.0924), stream from Tekek Bay, Pulau Tioman, coll. P.K.L. Ng, 23 June 1983; 7 males, 7 females ( ZRC 1996.1725), Pulau Tioman, Sungei Keliling, coll. P.K.L. Ng, 27–28 June 1996; 1 male ( ZRC 1998.850), Pulau Tioman, Sungei Keliling, coll. P.K.L. Ng et al., 26 June 1997; 1 male ( ZRC 1998.851), Malaysia, Sungei Paya, Pulau Tioman, coll. P.K.L. Ng et al., 25 June 1997; 2 males, 1 female ( ZRC 2019.1115), Sungei Paya, Tioman, Malaysia, coll. R. Diesel, 1995. SINGAPORE – 1 male ( ZRC 1967.7.10.29), Sungei Seletar, coll. C.L. Soh, 15 January 1967; 1 female ( ZRC 1967.7.10.33), Sungei Seletar, coll. C.L. Soh, 18 April 1968; 1 male ( ZRC 1967.7.10.32), Sungei Seletar, coll. C.L. Soh, 31 December 1966; 1 male ( ZRC 1967.7.10.28), Sungei China, coll. C.L. Soh, 15 January 1967; 1 male ( ZRC 1967.7.10.30), Sungei Seletar, coll. C.L. Soh, 31 December 1966; 1 female ( ZRC 1967.7.10.31), Sungei Seletar, coll. C.L. Soh, 21 March 1966; 1 male ( ZRC 1973.11.2.492), Sungei Seletar, coll. C.L. Soh, 6 May 1966; 1 male ( ZRC 2000.2018), Singapore, Pulau Ubin, caught dead, coll. C.D. Schubart, July 2000; 1 young female ( ZRC), freshwater swamp, Belang, Pulau Tekong, Singapore, coll. K.K.P. Lim, 17 November 2012.

Diagnosis. Anterior dorsal carapace regions with scattered short black setae to almost glabrous; outer surface of adult chela covered with relatively smaller flattened granules, those on margins especially smaller, sharper; margins of ambulatory segments with scattered short setae; male pleon relatively transversely broader; G1 relatively more slender, chitinous distal part almost straight, proportionately more narrow.

Colour. In life, the carapace is dark purplish-black, with the posterior part sometimes lighter grey; lateral margins yellow to orange; outer surface of chela purple with orange to almost red fingers ( Fig. 57B–H ) (see also Rademacher & Mengedoht, 2011: 30).

Remarks. Targioni-Tozzetti (1877: 141) used the name “ Sesarma cheirogona ” for the species without any explanation of the etymology. The name is derived from the Greek Χειρός (cheira) for hand, and γωνία (gonía) for angle or joint; clearly alluding to the distinctive chela of the species. Targioni- Tozzetti (1877) probably did not intend to use the name as a noun as it should then have been spelled “ cheirogonia ”. Like most workers during that time, the gender of the name Sesarma was regarded as a feminine, and as such, he probably used “ cheiragona ” to reflect this.

For differences with C. bocourti , see Remarks for that species.

Biology. Ng (1995: 202) summarises the following observations about its ecology (as Pseudosesarma bocourti ): “In the ZRC is a large series of this species from freshwater swamps in Kota Tinggi, Johor which had been collected by the late Michael Tweedie. I have also obtained specimens from coastal peat swamps in Pekan (Pahang) and Sarawak. The present specimens agree very well with these specimens. They dig burrows in the peat substrate, often among roots and debris, and emerge only late at night to feed on dead leaves and other vegetable matter. The crabs are terrestrial in habits and have been obtained several hundred metres from the nearest water source. The habitat (a coastal peat swamp) where they were collected, the beginning of the Ulu Assam trail, is only about 300 metres from the sea”.

Distribution. Sumatra, Borneo, Peninsular Malaysia, and Singapore.

Figures

Fig. 23. A, E, Contusarma bocourti, lectotype male (24.0 × 27.2 mm) (MNHN D-10965), Bangkok, Thailand; B, F, C. bocourti, male (25.3 × 23.3 mm) (ZRC 2000.0952), Bangkok, Thailand; C, C. bocourti, female (21.1 × 19.0 mm) (ZRC 2019.1114), Bangkok, Thailand; D, H, C. cheirogonum, neotype male (24.5 × 21.5 mm) (ZRC 1995.225), Bako National Park, Sarawak; G, C. cheirogonum, male (23.0 × 20.7 mm) (ZRC 2000.2018), Pulau Ubin, Singapore. A–D, overall habitus; E–H, anterior half of carapace.

Fig. 25. Frontal view of cephalothorax of Pseudosesarma. A, P. edwardsii, lectotype male (17.5 × 16.1 mm) (RMNH-D17a), Mergui Archipelago; B, P. edwardsii, male (13.4 × 11.9 mm) (ZRC 1965.8.2.81), Pulau Pawai, Singapore; C, P. crassimanum, male (15.9 × 14.5 mm) (RMNH-D23313), Singapore; D, P. anteactum, holotype male (16.7 × 14.7 mm) (ZRC 2016.0602), Sri Lanka; E, P. glabrum, holotype male (13.8 × 12.0 mm) (CUSAT 2016-1), Kerala, India; F, P. brehieri, holotype male (17.4 × 15.7 mm) (ZRC 2016.0593), Myanmar; G, P. boulengeri, lectotype male (26.9 × 23.5 mm) (NHM 1919.11.14.1), Basra, Iraq; H, Contusarma bocourti, male (25.3 × 23.3 mm) (ZRC 2000.0952), Bangkok, Thailand; I, Contusarma cheirogonum, neotype male (24.5 × 21.5 mm) (ZRC 1995.225), Bako National Park, Sarawak; J, Miersarma granosimanum, lectotype male (16.9 × 14.8 mm) (NHM 1880.6), Borneo.

Fig. 28. Chela of Contusarma. A, C. bocourti, lectotype male (24.0 × 27.2 mm) (MNHN D-10965), Bangkok, Thailand; B, C, C. bocourti, male (25.3 × 23.3 mm) (ZRC 2000.0952), Bangkok, Thailand; D, C. cheirogonum, neotype male (24.5 × 21.5 mm) (ZRC 1995.225), Bako National Park, Sarawak. A, B, D, outer view; C, ventro-marginal view.

Fig. 31. Male anterior thoracic sternum and pleon. A, Contusarma bocourti, male (25.3 × 23.3 mm) (ZRC 2000.0952), Bangkok, Thailand; B, Contusarma cheirogonum, male (15.3 × 14.0 mm) (ZRC 2011.0924), Pulau Tioman, Malaysia; C, Contusarma cheirogonum, neotype male (24.5 × 21.5 mm) (ZRC 1995.225), Bako National Park, Sarawak; D, Miersarma granosimanum, lectotype male (16.9 × 14.8 mm) (NHM 1880.6), Borneo; E, Miersarma granosimanum, male (22.5 × 19.2 mm) (ZRC 1965.7.29.164), Sedili River, Johor, Malaysia; F, Bresedium laevimanum, lectotype male (20.0 × 17.6 mm) (MNHG), Borneo; G, Bresedium laevimanum, male (26.3 × 23.7 mm) (NHM) (lectotype of Sesarma sediliensis), Johor, Malaysia; H, Bresedium laevimanum, male (21.2 × 18.2 mm) (ZRC 1965.7.29.121), Johor, Malaysia.

Fig. 32. Male sternopleonal cavity. A, Pseudosesarma edwardsii, male (20.8 × 18.6mm (ZRC 2003.0084), Pulau Tekong, Singapore; B, Pseudosesarma crassimanum, male (15.1 × 13.3 mm) (ZRC 2000.1768), Sungei Benut, Johor, Malaysia; C, Contusarma cheirogonum, male (15.3 × 14.0 mm) (ZRC 2011.0924), Pulau Tioman, Malaysia; D, Miersarma granosimanum, male (22.5 × 19.2 mm) (ZRC 1965.7.29.164), Sedili River, Johor, Malaysia. Arrow indicates shallow depression on somite 5 to accept G1 tip when pleon closed (depression absent in Miersarma, D).

Fig. 39. Contusarma cheirogonum. A–C, holotype male of Sesarma cheirogona (after Targioni Tozzetti, 1877: pl. 9 fig. 2); D, E, F–J, K, male (26.3 × 23.0 mm) (ZRC 1995.226), Bako National Park, Sarawak; L–N, neotype male (24.5 × 21.5 mm) (ZRC 1995.225), Bako National Park, Sarawak; O, male (24.5 × 21.3 mm) (ZRC 1964.9.28.140), Johor, Malaysia; P, male (22.3 × 20.5 mm) (ZRC 1964.9.28.127), Saribas, Sarawak; Q, male (28.8 × 25.5 mm) (ZRC 1964.9.28.126), Saribas, Sarawak. A, D, carapace; B, outer view of left chela; C, thoracic sternites and pleon; E, O–Q, pleon; F, L, left G1 (dorsal view, denuded); M, G, H, left distal part of G1 (dorsal view, denuded); N, I, left distal part of G1 (mesial view); J, left distal part of G1 (ventral view, denuded); K, left G2 (denuded). A–C, after Targioni Tozzetti (1877: pl. 9 fig. 2); D, H, J, K, after Ng (1995: fig. 14). Scales: D, E, K, O–Q = 5.0 mm; F, L = 2.0 mm; G–K, M, N = 1.0 mm.

Fig. 44. Vulva. A, Pseudosesarma edwardsii, female (16.5 × 15.3 mm) (ZRC 2016.0608), Malaysia; B, Pseudosesarma crassimanum, female (15.9 × 13.8 mm) (ZRC 2000.1768), Malaysia; C, Pseudosesarma crassimanum, female (18.0 × 15.7 mm) (ZRC 2017.1045), Thailand; D, Pseudosesarma anteactum, paratype female (17.5 × 15.4 mm) (ZRC 2016.0603), Sri Lanka; E, Pseudosesarma brehieri, paratype female (14.9 × 13.4 mm) (ZRC 2016.0594), Myanmar; F, Pseudosesarma boulengeri, female (24.2 × 20.0 mm) (ZRC 2014.0335), Iran; G, Contusarma bocourti, female (21.1 × 19.0 mm) (ZRC 2019.1114), Thailand; H, Contusarma cheirogonum, female (26.6 × 23.0 mm) (ZRC 1964.9.28.127), Sarawak; I, Miersarma granosimanum, female (20.1 × 16.4 mm) (ZRC 1965.7.29.166), Malaysia; J, Manarma moeschii, female (19.3 × 17.3 mm) (ZRC 2017.0170), Thailand.

Fig. 57. Colour in life. A, Contusarma bocourti, male (25.3 × 23.3 mm) (ZRC 2000.0952), Bangkok, Thailand [photograph: Phaibul Naiyanetr]; B–D, C. cheirogonum, male (26.3 × 23.0 mm) (ZRC 1995.0226), Bako, Sarawak [photograph: PKL Ng]; E, G, C. cheirogonum, male, Tioman, Peninsular Malaysia, specimen not collected [photograph: Chua Ee Kiam]; F, C. cheirogonum, Tioman, Peninsular Malaysia, female (specimen not collected); H, C. cheirogonum, specimen not collected, Bako, Sarawak [photograph: Jongkar Grinang].