A new species of Rhabdops Boulenger, 1893 (Serpentes: Natricinae) from the northern Western Ghats region of India

Abstract

Based on analyses of new DNA sequence data for two nuclear (rag1, cmos) and three mitochondrial (16s, cytb, nd4) genes, the Indian snake genus Rhabdops is a natricine. Variation in geography, DNA sequences, the number of ventral scales, pattern and colour for samples of Rhabdops from along the Western Ghats region of peninsular India is concordant, discontinuous and bimodal. We recognise populations from the northern Western Ghats as distinct specifically from the more southerly R. olivaceus and describe Rhabdops aquaticus sp. nov. based on a series of eight specimens from two localities in the Northern Western Ghats. Rhabdops aquaticus sp. nov. is associated particularly with upland laterite plateaus and their associated streams, a threatened habitat within its known distribution.

A new genus and species of natricine snake from northeast India

“…Prior to Giri et al's (2017) description of Rhabdops aquaticus and the present study, Rhabdops was generally considered Colubridae incertae sedis and to comprise only two species with a pronounced disjunct Western Ghatsnortheast India distribution (e.g. Smith 1943).…”

“…Other similar herpetofaunal examples include the lizard genus Salea, previously thought to occur in northeast India as well as the Western Ghats but now, following taxonomic revision, considered restricted to the latter (Mahony 2010); and the skink Scincella, the frog Polypedates, and the toad Pedostibes, for which all Western Ghats (and any Sri Lankan) species have been transferred to new genera, leaving the remaining species restricted to northeast India (and some into Indochina and/or southeast Asia) (Eremchenko & Das, 2004;Zachariah et al 2011;Chandramouli & Amarasinghe 2016). The natricine snake Atretium comprises two nominal species considered to have a disjunct, Yunnan versus (largely southern) India and Sri Lanka distribution, but molecular phylogenetic analyses have recovered the genus as non-monophyletic (Figueroa et al 2016;Giri et al 2017;this study). Intact examples of disjunct Western Ghats versus northeast India distributions for amphibians and reptiles include the skink Sphenomorphus and frog Clinotarsus.…”

“…The colubrid snake genus Rhabdops Boulenger, 1893 is conceived currently as comprising three species-the type species, R. olivaceus (Beddome, 1863) and recently described R. aquaticus Giri, Deepak, Captain & Gower, 2017, both from the Western Ghats region of peninsular India, and R. bicolor (Blyth, 1854) from northeast India and adjacent regions of Myanmar and possibly China (Anderson 1879;Dowling & Jenner 1988;Smith 1943;Wallach et al 2014;Giri et al 2017). In addition to describing a new species, Giri et al (2017) recently carried out the first molecular phylogenetic analysis for Rhabdops and found support for a very close relationship between the two peninsular Indian species, and for their inclusion within the colubrid subfamily Natricinae. Giri et al's (2017) taxon sampling for their molecular phylogenetic analyses did not include the northeast Indian R. bicolor.…”

“…In addition to describing a new species, Giri et al (2017) recently carried out the first molecular phylogenetic analysis for Rhabdops and found support for a very close relationship between the two peninsular Indian species, and for their inclusion within the colubrid subfamily Natricinae. Giri et al's (2017) taxon sampling for their molecular phylogenetic analyses did not include the northeast Indian R. bicolor.…”

Discovery of a deeply divergent new lineage of vine snake (Colubridae: Ahaetuliinae: Proahaetulla gen. nov.) from the southern Western Ghats of Peninsular India with a revised key for Ahaetuliinae

“…There have been intensive explorations of WG biodiversity in the last decade revealing many new genera and species of trees [3–6], invertebrates [7,8], fish [9] and birds [10]. An increasing number of herpetological expeditions, and interest in the region, has also resulted in many discoveries [11–20]. This has steadily increased the importance of this biodiversity hotspot for conservation.…”