Indian Brown Vine Snake

description

Description of neotype. Adult of total length 1765 mm; dissected; very slender, partially laterally compressed body with snout to vent length 1054 mm; tail length 711 mm; ventrals 179 notched with keels; subcaudals 162 divid-ed; cloacal scale divided; relatively long and slender tail; dorsal scale rows in 15 - 15 - 11 rows of smooth, obliquely disposed scales; head very distinct from neck with head length 49.1 mm; transversely oval eyes with horizontal pupil, with a horizontal diameter of 3.4 mm and vertical diameter of 2.3 mm; distance from nostril to eye 11.1 mm; distance from snout tip to eye 18.3 mm; supralabials 8 (both left and right) with 5 th supralabial being the largest, in contact with the eye; 4 th supralabial divided; infralabials 7 (both left and right); 2 nd, 3 rd and 4 th infralabials in contact with the anterior genials; 4 th and 5 th infralabials in contact with the posterior genials; nasal 1 (both left and right); loreals absent; pre-subocular 2 (both left and right); pre-ocular 1 (both left and right); post-oculars 2; sub-oculars absent; temporal 3 + 3 + 1 (both left and right); prefrontal scale in contact with pre-oculars; preventrals 2; rostral appendage compr

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

description

Nomenclatural remarks. As the Western Ghats population of A. pulverulenta sensu lato is diagnosed to be distinct at species rank from the Sri Lankan population, the available subspecific nomen Dryophis pulverulenta indica Deraniyagala, 1955 listed as a subjective synonym, should be conferred on it. However, in the Ahaetulla prasina group, there is an available subspecific nomen Dryophis prasinus indicus Mell, 1931. These nomina are available names and represent taxa that are currently considered congeneric (Wallach et al. 2014). Thus, Dryophis pulverulenta indica Deraniyagala, 1955 becomes a primary junior homonym of Dryophis prasinus indicus Mell, 1931. As Deraniyagala’s (1955) nomen is junior to Mell’s (1931) nomen and is thus permanently invalid, and as both these nomina were originally erected at the same taxonomic rank (as subspecific nomina), we consider these nomina as congeneric. As no other subjective synonym is available for the preoccupied nomen (see Wallach et al. 2014), according to Art. 57.2, 59.1 and 60.3 of the Code, we herein erect a new replacement name Ahaetulla sahyadrensis nom. nov. to resolve this case of primary homonymy.

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 sahyadrensis nom. nov. (L 7) is nested with the clade comprising A. pulverulenta (L 8), A. oxyrhyncha comb. nov. (L 1) and A. anomala. It is sister to the clade comprising A. oxyrhyncha comb. nov. and A. anomala. 2. There is a low level (3.2 % in Cytb & 0.4 % in 16 S) of genetic divergence between A. sahyadrensis nom. nov. and members (CESS 211, CESS 244, CESS 506, CESS 521 & CESS 528) of Ahaetulla oxyrhyncha (Bell, 1825) comb. nov. Ahaetulla anomala also differs from A. sahyadrensis nom. nov. with a low (3.2 % in Cytb and 0.8 % in 16 S) level of genetic distance. In addition, A. sahyadrensis nom. nov. shows a moderate level (4.52 % in Cytb and 1.7 % in 16 S) of genetic divergence from Sri Lankan A. pulverulenta. Also, A. sahyadrensis nom. nov. differs from the superficially similar, brown coloured A. laudankia as the latter belongs to a separate clade that clusters with Southeast Asian rather than South Asian taxa. 3. This is a species of usually grey-brown coloured Ahaetulla having an elongate multi-scaled rostral appendage and a rhomboid crown marking (vs. rostral scale not multi-scaled in all other sympatric Ahaetulla spp.; except A. an

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. Ahaetulla sahyadrensis nom. nov. is herein recorded from the Central Western Ghats. However, the actual distribution range will stretch across the Western Ghats (McCann 1940; Das 2002; Whitaker & Captain 2004), possibly distributed in moist deciduous and evergreen forests from just above sea level till 1500 msl (metres above sea level). They are primarily arboreal, occasionally terrestrial and found in the vicinity of perennial streams.

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