Günther's Vine Snake

description

Description of Referred Material CESS 188. Adult of total length 633 mm; dissected; very slender, partially laterally compressed body with snout to vent length 410 mm; tail length 223 mm; relative tail length 0.35; ventrals 147 notched with keels; subcaudals 113 divided; cloacal scale divided; relatively long and slender tail; dorsal scale rows in 15 - 15 - 13 rows of smooth, obliquely disposed scales; head very distinct from neck with head length 21 mm; transversely oval eyes with horizontal pupil, with a horizontal diameter of 3.2 mm and vertical diameter of 1.6 mm; distance from nostril to eye 5.1 mm; distance from snout to eye 6.5 mm; supralabials 8 (both left and right) with the 6 th supralabial being the largest, 5 th supralabial in contact with the eye; 4 th supralabial divided; infralabials 9 (both left and right); 1 st, 2 nd, 3 rd and 4 th infralabials in contact with anterior genials; 4 th and 5 th infralabials in contact with posterior genials; mental scale wedged in between 1 st pair of infralabials not in contact with genials; nasal scale 1 (both left and right); loreals absent; pre-suboculars 2 (both left and right); pre-ocular 1 (both left and right); postoculars 2;

Disentangling vines: a study of morphological crypsis and genetic divergence in vine snakes (Squamata: Colubridae: Ahaetulla) with the description of five new species from Peninsular India

diagnosis

Diagnosis. 1. Phylogenetically, Ahaetulla dispar (L 11) is closely related to its sister, Ahaetulla travancorica sp. nov. (L 12). The clade comprising Ahaetulla dispar and Ahaetulla travancorica sp. nov. shares ancestry with an-other clade comprising lineage L 3 – L 6 (from the Western Ghats) and Ahaetulla nasuta (L 2 from Sri Lanka) (Fig. 1). 2. There is a moderate level (4.1 % in Cytb & 1.1 % in 16 S) of genetic divergence between A. dispar and Ahaet-ulla travancorica sp. nov. 3. Ahaetulla dispar differs from Ahaetulla travancorica sp. nov. by possessing 0 – 1 loreals on each side of the head as compared to 2 loreals in Ahaetulla travancorica sp. nov., 9 infralabials in A. dispar (vs. 7 – 8 in Ahaetulla travancorica sp. nov.), no keels on the dorsal row of scales (vs. mild keels present) (Fig. 21). 4. Geographically, both A. dispar and A. travancorica sp. nov. are separated from each other by the Shencot-tah Gap located in the Southern Western Ghats. Ahaetulla dispar occupies a range to the north of the Shen-cottah gap, while Ahaetulla travancorica sp. nov. is distributed to the south of the gap. Ahaetulla dispar predominantly occurs in higher (> 1400 m asl) elevations compared t

Disentangling vines: a study of morphological crypsis and genetic divergence in vine snakes (Squamata: Colubridae: Ahaetulla) with the description of five new species from Peninsular India

distribution

Distribution and habitat. It is distributed in the Southern Western Ghats starting from Anaimalai hills and extending towards the region north of the Shencottah Gap. We doubt its purported presence in Nilgiri-Waynad, as has been mentioned in Hutton & David (2009). As a high elevation shola-grassland specialist, this species is found above 1400 msl. The snake is found predominantly in grasslands, exhibiting a terrestrial lifestyle similar to A. travancorica sp. nov. and A. perroteti.

Disentangling vines: a study of morphological crypsis and genetic divergence in vine snakes (Squamata: Colubridae: Ahaetulla) with the description of five new species from Peninsular India

etymology

Etymology. Named after its disparate colouration, a sexually dichromatic species with green males and predominantly brown adult females (one of the earliest known dichromatic snake see Günther, 1864; Darwin 1871 contra Mohapatra et al. 2017).

Disentangling vines: a study of morphological crypsis and genetic divergence in vine snakes (Squamata: Colubridae: Ahaetulla) with the description of five new species from Peninsular India