Friday, April 16, 2021

[Herpetology • 2021] Xylophis deepaki • A New Species of Xylophis Beddome, 1878 (Serpentes: Pareidae) from the southern Western Ghats of India

Xylophis deepaki 
Narayanan, Mohapatra, Balan, Das & Gower, 2021

We reassess the taxonomy of the Indian endemic snake Xylophis captaini and describe a new species of Xylophis based on a type series of three specimens from the southernmost part of mainland India. Xylophis deepaki sp. nov. is most similar phenotypically to X. captaini, with which it was previously confused. The new species differs from X. captaini by having a broader, more regular and ventrally extensive off-white collar, more ventral scales (117–125 versus 102–113), and by lack of flounces on the body and proximal lobes of the hemipenis. Phylogenetic analysis of mitochondrial 16S DNA sequences strongly indicates that the new species is most closely related to X. captaini, differing from it by an uncorrected pairwise genetic distance of 4.2%. A revised key to the species of Xylophis is provided.

Keywords: Hemipenis, Kanyakumari, molecular phylogeny, snakes, taxonomy, Xylophiinae

Figure 5. Xylophis deepaki sp. nov. showing colour in life.
A. Holotype ZSI-CZRC-V-7218, B. Paratype ZSI-SRC-VRS-287.

Xylophis deepaki sp. nov.
Xylophis perroteti – Rajendran (1985). [Chresonym]
Xylophis captaini – Gower and Winkler, 2007 [in part]; Ganesh (2010); Ganesh et al. 2012; Bhupathy et al. 2016 [in part] [Chresonym]

Diagnosis: The new species is assigned to the genus Xylophis based on the anterior-most (three) pairs of infralabial shields reduced to narrow strips, together much smaller than large pair of anterior chin (genial) shields. Xylophis deepaki sp. nov. is small (maximum known total length 199 mm), with 15 dorsal scale rows at midbody, 117–125 ventrals (n=6), 13–23 subcaudals (n=6), internasal length almost equal to the prefrontal length, a thick and ventrally near-complete off-white collar, and mostly smooth hemipenial body and lobes.

Etymology: This species is named in honour of the Indian herpetologist Dr Deepak Veerappan, in recognition of his substantial, 21st Century contributions to herpetology, including work on Xylophis systematics. We suggest the common name Deepak’s wood snake (English).

Figure 2. Distribution of Xylophis captaini and Xylophis deepaki sp. nov. in the Western Ghats based on specimens examined in this study and observations of uncollected animals reported in the text.

Figure 8. Habitat of Xylophis deepaki sp. nov. in Melpuram, Kanyakumari Dist., Tamil Nadu, showing some banana and coconut within rubber plantation.

 Surya Narayanan, Pratyush P. Mohapatra, Amirtha Balan, Sandeep Das and David J. Gower. 2021. A New Species of Xylophis Beddome, 1878 (Serpentes: Pareidae) from the southern Western Ghats of India. Vertebrate Zoology. 71: 219-230. DOI: 10.3897/vz.71.e63986