Coelognathus cf. subradiatus (Schlegel, 1837)

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 : 267

Coelognathus cf. subradiatus —Erroneous.

Sunda Rat Snake

( Figure 27C & 27D )

Singapore records.

Coluber hodgsonii — Hanitsch, 1898: 10.— Flower, 1899: 668.— Hanitsch, 1912b: 16.

Coluber Hodgsoni —Ridley, 1899: 208.

Elaphe taeniura —Sworder, 1923: 63.

Remarks. A specimen in the ZRC collections (no catalogue data) identified as “ Coluber hodgsoni ” was first reported by Hanitsch (1898) in an annual report of the museum’s holdings. Flower (1899), Ridley (1899), and Hanitsch (1912b) all refer to the same specimen. Sworder (1923) later amended the identification to Elaphe taeniura after Malcolm Smith examined the specimen and stated, “that this specimen appears to be an intermediate form between the common form and the variety (ridleyi) which inhabits caves.” Sworder (1923) also noted that the identification as “ Coluber hodgsoni ” must be incorrect given that the species “is only known from a limited range, in the Himalayan region”, making “the record of a specimen from Singapore … somewhat startling”.

After examining specimen ZRC.2.4537, we find that it closely identifies with Coelognathus subradiatus ( Fig. 27C, D ). One of the main characters differentiating Coelognathus from species of Elaphe formerly classified under Orthriophis , is that the last supralabial touching the eye also touches the temporals (Smith 1943). ZRC.2.4537 possesses a presubocular, which C. subradiatus is the only species in the genus having this trait (Utiger et al. 2005). Diagnosis of ZRC.2.4537 is as follows: snout-vent-length 125.0 cm; tail length 37.0 cm; 230 ventrals; 111 subcaudals; anal plate divided; dorsals 27:25:19; 1 loreal; 1 preocular; 2 postoculars; 1 presubocular present; 8 supralabials (IV and V touching the eye, and V touching the first two temporals); 9 infralabials (III–V touching the anterior chin shield); 2+3+4 temporals; dorsal dark brown above with irregular light spots; venter yellowish anteriorly with brown mottling transitioning to uniform dark brown posteriorly. Coelognathus subradiatus is native to the Lesser Sunda Islands of Indonesia and Timor-Leste (Wallach et al. 2014).

LKCNHM & NHMUK Museum specimens. Singapore (no locality): ZRC.2.4537 (no date).

Additional Singapore museum specimens. No specimens.

Genus Elaphe Fitzinger in Wagler, 1833 (1 species)

Figures

FIGURE 27. A) Indotyphlops albiceps, B) Indotyphlops porrectus, and C–D) Coelognathus cf. subradiatus. Photographs by: Evan S.H. Quah [A], Dan Rosenberg [B], and Kelvin K.P. Lim [C–D].