Xenelaphis hexagonotus (Cantor, 1847)

Figueroa, Alex, Low, Martyn E. Y. & Lim, Kelvin K. P., 2023, Singapore’s herpetofauna: updated and annotated checklist, history, conservation, and distribution, Zootaxa 5287 (1), pp. 1-378 : 176-177

Xenelaphis hexagonotus (Cantor, 1847) — Native.

Coluber hexahonotus Cantor, 1847: 921 , 922. Holotype: BMNH 1946.1 .14.86, by original designation. Type locality: “Great Hill of Pinang ” (= Penang Island ), Peninsular Malaysia.

Malayan Brown Snake

( Figure 20C )

Singapore records.

Coryphodon hexahonotus [sic]— Ģnther, 1858b: 110.

Coluber hexahonotus [sic]—Peters, 1859: 269.

Xenelaphis hexahonotus [sic]— Ģnther, 1864: xx, 251.—Theobald, 1868a: 46.—F. M̧ller, 1887: 263.— Hoffmann, 1890b: 1692.

Xenelaphis hexagonotus — Boulenger, 1894: 8.— Flower, 1896: 882.— Flower, 1899: 667.—Ridley, 1899: 208.— Boulenger, 1912: 139.— Hanitsch, 1912b: 16.— de Rooij, 1917: 93.—Sworder, 1923: 63.— de Haas, 1950: 546.—F.L.K. Lim & M.T.-M. Lee, 1989: 116.—K. Lim, 1990a: 7 (Seletar Reservoir; Seletar Reservoir Park [USRP]).—K.K.P. Lim & L.M. Chou, 1990: 54.—K.K.P. Lim & F.L.K. Lim, 1992: 66, 146.—L.M. Chou et al., 1994: 105.—K. Lim, 1995: 15 (Dairy Farm Path [BTNR).— David & Vogel, 1996: 111.— Manthey & Grossmann, 1997: 396.—R.C.H. Teo & Rajathurai, 1997: 383.—Chan-ard et al., 1999: 36.— Iskandar & Colijn, 2001: 85.—K.P. Lim & F.L.K. Lim, 2002: 147.—N. Baker & K.P. Lim, 2008: 108, 161.— Das, 2010: 302.—D.C.J. Yeo et al., 2010: 154.—P.K.L. Ng et al., 2011: 272.—N. Baker & K.P. Lim, 2012: 108, 161.— Das, 2012a: 69.— Gumprecht & Schulz, 2013: 410.—Schulz, 2013: 197.—N. Baker, 2014b: 16–18 (Upper Seletar Reservoir Park).—Wallach et al., 2014: 795.—Chan-ard et al., 2015: 172.— de Lang, 2017: 193.— Das, 2018: 80.—R.C.H. Teo & Thomas, 2019: 164, 181 (Bukit Timah Nature Reserve, after R.C.H. Teo & Rajathurai, 1997).— Charlton, 2020: 199.

Xenelaphis hexagonatus [sic]— Hanitsch, 1898: 20.— Buddle, 1929: 19 (Sembawang Naval Base [= SML]).—K.K.P. Lim et al., 2008: 265.

Remarks. Xenelaphis hexagonotus is a rare snake in Singapore ( Baker & Lim 2012), and has only been reported a few times. Ģnther (1858b) first reported it from Singapore from two specimens belonging to Hardwicke’s collection and one collected by Blanford ( Boulenger 1894). Peters (1859) listed a specimen at ZMB collected by Jagor, and Hanitsch (1898) and Ridley (1899) mentioned specimens at the Raffles Museum, but did not provide any details. Flower (1896) commented that he collected two specimens in Singapore, but did not provide detailed locality data. Subsequently, Buddle (1929) collected two at SNB, then X. hexagonotus was not documented again in Singapore until 61 years later ( Table 2 ) on 4 May 1990 when one was observed swallowing a Monopterus albus at USRP, and two others were seen on 23 May 1990, also at USRP ( Lim 1990a). Five years later, a snake resembling X. hexagonotus was seen at BTNR, but was not confirmed (Lim 1995). Teo & Thomas (2019) informed that one of the records reported by Teo & Rajathurai (1997) was from BTNR, likely referring to Lim (1995). The last, and only other published account of X. hexagonotus , is of three individuals seen in streams at USRP, two on 18 and 20 September 2005 and one on 2 October 2010 ( Fig. 20C ) ( Baker 2014b). Three unpublished records include one observed eating a fish at LPF on September 2015 (Jayasri pers. comm.), two captured during aquatic biodiversity surveys in May 2016 (T. Li pers. comm.), and a juvenile seen at MacRitchie on 27 September 2018 (D. Ng pers. comm.). In addition, the LKCNHM has two specimens from 1917 and one from 1966.

Occurrence. Restricted to CNR and surrounding Nature Parks. Rare.

Singapore conservation status. Critically Endangered.

Conservation priority. Highest.

IUCN conservation status. Least Concern [2012].

LKCNHM & NHMUK Museum specimens. Singapore (no locality) : BMNH 1888.7 .10.4 (no date) , BMNH 1930.12 .2.2 (no date) , BMNH 1969.2703 – 2704 (no date); Botanic Gardens : ZRC.2.4364 (Apr-1897) , ZRC.2.4363 (05-Sep-1917) , ZRC.2.4362 (03-Oct-1917) ; MacRitchie Forest [ MNF] : ZRC.2.7335 (27- Jul-2018) ; Mandai : ZRC.2.2588 (03-Jul-1966) ; Nee Soon Swamp Forest : ZRC.2.2606 (23-May-1990) , ZRC.2.5531 (14-Oct-2002) ; Rifle Range Road : ZRC.2.6063 (06-May-2004) ; Seletar Reservoir South : ZRC.2.2599 (04-May-1990) .

Additional Singapore museum specimens. Singapore (no locality): CAS, ZMB; Mandai Road: CAS.

Singapore localities. Bukit Timah Nature Reserve—Lower Peirce Forest—MacRitchie (not specified)—MacRitchie North Forest—Mandai Road—Nee Soon Swamp Forest—Rifle Range Road—Sembawang Naval Base*— Singapore Botanic Gardens*—Upper Seletar Reservoir Park.

Subfamily Natricinae Bonaparte, 1838 (5 species)

Natricinae Bonaparte, 1838: 392 (type genus Natrix Laurenti, 1768 ).

Genus Hebius Thompson, 1913 (1 species)

Hebius Thompson, 1913: 424 (type species: Tropidonotus vibakari H. Boie in F. Boie, 1826, by monotypy; gender masculine).

Figures

FIGURE 20. A) Ptyas fusca, B) Ptyas korros, C) Xenelaphis hexagonotus, D) Hebius petersii E) Rhabdophis rhodomelas, F) Xenochrophis maculatus, G) Xenochrophis trianguligerus, and H) Xenochrophis trianguligerus. Photographs by:Alex Figueroa [A, E–F], Emmanuel Goh [B], Nick Baker [C], Kelvin K.P. Lim [D, G], and Evan S.H. Quah [H].