Ahaetulla isabellina

Wall's vine snake
In Kalakkad Mundanthurai Tiger Reserve, Tamil Nadu
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Colubridae
Subfamily: Ahaetuliinae
Genus: Ahaetulla
Species:
A. isabellina
Binomial name
Ahaetulla isabellina
(Wall, 1910)
Synonyms[1]

Dryophis mycterizans isabellinus Wall, 1910

Ahaetulla isabellina,[1][2] also known as Wall's vine snake,[3] is a species of tree snake endemic to the southern Western Ghats of India.[1][2][3][4]

Taxonomy

It was formerly considered a subspecies of A. nasuta, which is now considered to only be endemic to Sri Lanka. A 2020 study found A. nasuta to be a species complex of A. nasuta sensu stricto as well as A. borealis, A. farnsworthi, A. isabellina, and A. malabarica, elevating A. isabellina to species. The specific epithet is a reference to the isabelline yellow coloration of the species' dorsal body in live condition, which distinguishes it from other species in the complex.[2]

Description

Body, very slender, bright green with blue obscure patches; in some specimens uniform olive to light brown. Rostral scale, infralabials and the midbody along venter are light green to light blue; sometimes there is a yellow ventral stripe along the notched ventral keels. Inter-scalar skin is white with black and white anteriorly-converging bars along forebody, becoming reddish along hindbody. Tail and subcaudals are green. The eye vary from yellow to orange with light brown marbled patterns; horizontal pupil with a light blue or yellow colouration around pupil. Adults can reach up to 1 m of total length.[2]

In general, scalation shows the following intraspecific variations: ventrals 167–183 notched with keels; subcaudals (males) 159–167 divided and subcaudals (females) 105–149 divided; anal divided; scale rows around the body in 15-15–13/11 rows of smooth, obliquely disposed scales; supralabials 8–9, either 5th or 6th in contact with the eye; supralabial scale division on the 4th; infralabials 8–9; pre-suboculars 1 or 2; pre-ocular 1 (both left and right); postoculars 1 or 2; sub-oculars absent; temporals 1+2 or 2+2.[2]

Ahaetulla isabellina from Western Ghats, Central Kerala
Ahaetulla isabellina from Western Ghats, Central Kerala

Geographic range

This species is distributed in the southern Western Ghats in Tamil Nadu and Kerala south of the Palghat Gap, from the Anaimalai Hills south to Kalakkad reserve forest area, although more work is needed to determine the southern limit of the species' range.[2]

Habitat

This species is found in evergreen forests of the Western Ghats from ~550 m to 1475 above sea level.[2]

References

  1. ^ a b c Ahaetulla isabellina at the Reptarium.cz Reptile Database. Accessed 13 October 2023.
  2. ^ a b c d e f g Mallik, Ashok Kumar; Srikanthan, Achyuthan N.; Pal, Saunak P.; D’souza, Princia Margaret; Shanker, Kartik; Ganesh, Sumaithangi Rajagopalan (6 November 2020). "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". Zootaxa. 4874 (1): 1–62. doi:10.11646/zootaxa.4874.1.1. PMID 33311335. S2CID 228823754.
  3. ^ a b "The discovery of five new species of vine snakes in India". phys.org. Retrieved 26 November 2020.
  4. ^ Staff Reporter (14 November 2020). "New species of vine snakes discovered". The Hindu. ISSN 0971-751X. Retrieved 26 November 2020.