A new species of aquatic snake discovered in the northern Western Ghats

A new species of burrowing snake of the genus Rhabdops is described from the northern Western Ghats. This is a result of a collaborative effort between scientists from National Centre for Biological Sciences (NCBS), Bangalore; Natural History Museum (NHM), London, UK; Centre for Ecological Science (CES), Indian Institute of Science, Bangalore; Indian Herpetological Society (IHS), Pune; Wildlife Institute of India (WII), Dehradun; Kerala Forest Research Institute (KFRI), Peechi and College of Veterinary Science (CVS), Pookode. 

This discovery is a result of meticulous efforts of eight years by the first author Dr Varad Giri of NCBS, Dr David Gower from NHM, Dr V. Deepak of CES, Ashok Captain of IHS/ BNHS, Dr Abhijit Das of WII, Sandeep Das and KP Rajkumar of KFRI and R.L. Rathish of CVS.

The snakes of the genus Rhabdops, are endemic to India and two species Olive Forest Snake Rhabdops olivaceous and Bi-coloured Forest Snake Rhabdops bicolour were previously known. The Olive Forest snake is endemic to the Western Ghats and Bi-coloured Forest Snake is known from a few localities in the northeastern parts of India. This new species, Rhabdops aquaticus, ‘Aquatic Rhabdops’ is distinct from other two species.

This new species, Aquatic Rhabdops was previously considered as Olive Forest Snake owing to its similarities in some characters and distribution. The Olive Forest Snake was described in 1863 based on a specimen collected from Mananthavady in Wayanad District Kerala. This was considered as one of the rare snakes and was subsequently reported from a few localities in the Western Ghats region of Kerala, Tamil Nadu, Karnataka, Goa and Maharashtra. Although, the populations of this snake from the northern Western Ghats were considerably distinct in some morphological characters and colouration. The team conducted a detailed study, both using DNA and morphology, of the historical and recently collected specimens from various localities in the Western Ghats. Finally, these findings were submitted to a scientific journal, Zootaxa and this paper are published recently. The meticulous efforts thus confirmed the distinctiveness of this new species and the populations from the northern Western Ghats are now a new species.

We have named this new species after its aquatic nature as the adults are mostly associated with fresh water streams in the forest and juveniles are mostly seen in water logged conditions, mostly on rocky plateaus. This species is nocturnal, chiefly aquatic and seen foraging underwater like other water snakes. Interestingly the juveniles and adults are differently coloured and this ontogenic colour variation may be due to their habitat preference as juveniles and adults. This species is presently known from a few locations in Maharashtra, Goa and northern Karnataka. A medium sized snake - the largest known specimen is 950mm in length. It is non-venomous.