Bitia hydroides Gray, 1842

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 : 205

Bitia hydroides Gray, 1842 — Native; Indeterminate.

Bitia hydroides Gray, 1842: 64 . Holotype: BMNH 1946.1 .2.38 (formerly BM III.15.1.a), by original designation. Type locality: None stated/traced.

Gray’s Water Snake

( Figure 23F )

Singapore records.

Hipistes hydrinus — Dennys, 1880a: 3.— Blanford, 1881: 215.— Flower, 1896: 888.— Flower, 1899: 679.— Ridley, 1899: 208.— Boulenger, 1912: 166.— de Rooij, 1917: 194.—Sworder, 1923: 66.

Bitia hydroides — de Haas, 1950: 579.— Gyi, 1970: 187 (Nee Soon Jungle [NSSF]).—K.K.P. Lim & L.M. Chou, 1990: 54.—K.K.P. Lim & F.L.K. Lim, 1992: 147.—L.M. Chou, 1995: 105.— Iskandar & Colijn, 2001: 86.—K.P. Lim & F.L.K. Lim, 2002: 147.—J.C. Murphy, 2007: 52.—N. Baker & K.P. Lim, 2008: 169.— Das, 2010: 324.—N. Baker & K.P. Lim, 2012: 169.—J.C. Murphy & Voris, 2014: 10.—Wallach et al., 2014: 90.—Chan-ard et al., 2015: 247.—O’Shea, 2018: 536.— Charlton, 2020: 74.

Remarks. The occurrence of B. hydroides in Singapore is known from only four specimens.The first was documented by Dennys (1880a) and Blanford (1881) from a specimen at the Raffles Museum, but they did not provide an account of the species. Smedley (1931) described a specimen at the Raffles Museum of “unknown origin” that may likely be the specimen examined by Blanford (1881). The next report came 89 years later ( Table 2 ) when Gyi (1970) examined MCZ R-8984 and MCZ R-18392. Gyi (1970) provided the locality “Nee Soon Jungle”, but inspection of the MCZ catalogue reveals that the locality for both specimens is unknown. Being that B. hydroides inhabits river mouths and coastal areas (Murphy 2007), Nee Soon as a locale is credible given that Sungei Seletar once reached the present location of Upper Seletar Reservoir, and the area around Springleaf Forest and edges of NSSF appeared to be mangrove forest (Yee et al. 2011). The final specimen is ZMO K2373 which was collected in 1898. If B. hydroides still occurs in Singapore, we presume SBWR and MMMNP may provide the most suitable locations with their extensive mudflats.

Occurrence. Known only from four specimens predating 1898. Rare.

Singapore conservation status. Not Evaluated.

Conservation priority. Highest.

IUCN conservation status. Least Concern [2010].

LKCNHM & NHMUK Museum specimens. No specimens.

Additional Singapore museum specimens. Singapore (no locality): ZMO.

Singapore localities. Nee Soon Swamp Forest.

Genus Cantoria Girard, 1858a (1 species)

Figures

FIGURE 23. A) Hydrophis stokesii, B) Hydrophis stokesii, C) Laticauda colubrina, D) Naja sumatrana, E) Ophiophagus hannah, F) Bitia hydroides, G) Cantoria violacea, and H) Cerberus schneiderii. Photographs by: Kelvin K.P. Lim [A], Christopher J. Jolly [B], Philip Vogrinc [C], Alex Figueroa [D, G–H], Francis L.K. Lim [E], and Evan S.H. Quah [F].