Ahaetulla farnsworthi, Mallik & Srikanthan & Pal & D’Souza & Shanker & Ganesh, 2020

Mallik, Ashok Kumar, Srikanthan, Achyuthan N., Pal, Saunak P., D’Souza, Princia Margaret, Shanker, Kartik & Ganesh, Sumaithangi Rajagopalan, 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), pp. 1-62 : 34-37

Ahaetulla farnsworthi sp. nov.

Ahaetulla nasuta (not of Lacépède, 1789)— Hutton & David, 2009: 305 [part]

Holotype. BNHS 3588 ( CESS288 ); adult female; Bhadra Tiger Reserve , Karnataka; Coll. Saunak P. Pal, 2010. Paratypes. BNHS 3589 ( CESS066 ) ; adult male; Sakleshpur, Karnataka; Coll. Ashok Kumar Mallik, 2010 . Other referred material. CESS 111; adult female; Agumbe, Karnataka; Coll. Saunak P. Pal, 2010. CESS 158; adult female; Bhagavathi, Kudremukh National Park, Karnataka; Coll. Ashok Kumar Mallik, 2010. CESS 043; adult (sex unknown); Talakaveri, Karnataka; Coll. S. P. Vijayakumar, 2009. Type locality. Bhadra Tiger Reserve (13.554618 N 75.749851 E) in Central Western Ghats, Peninsular India .

Etymology. Dedicated to the physicist Dr. Hubert Farnsworth of the world of Futurama, for his efforts in resurrecting barking snakes from extinction. Name latinized and coined in the genitive singular case.

Diagnosis.

1. Ahaetulla farnsworthi sp. nov. (L4) is nested within the clade comprising three other new lineages (L3, L5 & L6) and a lineage from Sri Lanka (L2). It is genetically sister to A. isabellina comb. nov. with low bootstrap support.

2. It shows a low to moderate level of genetic divergence from A. borealis sp. nov. (4.7% in ND4, 4.6% in Cytb and 1.7% in 16S) and A. malabarica sp. nov. (3.7% in ND4, 4.6% in Cytb and 1.9% in 16S).

3. A species of Ahaetulla characterised by having short rostral appendage (vs. long in A. oxyrhyncha comb. nov.; A. anomala , A. laudankia ; vs. multi-scaled rostral appendage in A. pulverulenta , A. sahyadrensis nom. nov., A. anomala ); possessing white ventrolateral stripe (vs. absent in A. pulverulenta , A. sahyadren-sis nom. nov.), possessing 6 prediastemal and 11 postdiastemal maxillary teeth (vs. 7 and 9 in A. isabellina comb. nov., vs. 6 and 7 in A. malabarica sp. nov., vs. 6 and 8 in A. borealis sp. nov., vs. 7 and 7 in A. oxyrhyncha comb. nov.); usually green body colouration in both sexes (vs. usually grey-brown in A. sahya-drensis nom. nov., adult females brownish in A. anomala , A. dispar and A. perroteti ) ( Fig. 17 , Table 2 ).

4. Ahaetulla farnsworthi sp. nov. occupies a small range in the Central Western Ghats flanked by populations of A. borealis sp. nov. to the north and A. malabarica sp. nov. to the south with possible geographic gaps formed by rivers located in the region.

Description of Holotype. Adult of total length 1021 mm; very slender, partially laterally compressed body with snout to vent length 626 mm; tail length 395; relative tail length 0.38; ventrals 172 notched with keels; subcaudals 150 divided; cloacal scale divided; relatively long and slender tail; dorsal scale rows in 15-15-13 rows of smooth, obliquely disposed scales; head very distinct from neck with head length 26.5 mm; transversely oval eyes with horizontal pupil, with a horizontal diameter of 4.6 mm and vertical diameter of 3.8 mm; distance from nostril to eye 6.45 mm; supralabials 8 on left, 8 on right, with 6 th supralabial being the largest, 5 th supralabial in contact with the eye; 4 th supralabial divided; infralabials 9 (both left and right); 1 st, 2 nd, 3 rd and 4 th infralabials in contact with anterior genials; 4 th and 5 th infralabials in contact with posterior genials; mental scale wedged in between 1 st pair of infralabials not in contact with genials; nasal scale 1 (both left and right); loreals absent; pre-suboculars 2 (both left and right); pre-ocular 1 (both left and right); post-oculars 2 (both left and right); sub-oculars absent; temporals 2+3 on right and 2+3 on left; prefrontal scale in contact with pre-oculars; preventral 1.

Colour in life. Dorsum uniform bright green with minute brown dots; scales bordered with brown; pre-ocular scales with 2 dark blue dots bordered with light blue; rostral, infralabials, venter yellowish green to light green at mid body; yellow ventral stripe along notched ventral keels; slight discolouration in the pre-ocular; inter-scalar skin white with black and white bars anteriorly-converging bars; white replaced by reddish brown interscalar skin posteriorly; golden yellow eyes with black speckles; concentration of black speckles both in anterior and posterior ends of a horizontal pupil; a slight discolouration around the pupil; tail, subcaudals green.

Colour in preservative. Dorsum non-uniform bluish green to light blue; rostral, infralabials, venter white; white ventral stripe along notched ventral keels; slight discolouration in the pre-ocular; inter-scalar skin white with anteriorly-converging black and white bars; eyes yellow with white and black speckles; concentration of black speckles both in anterior and posterior ends of a dilated pupil.

Variation shown by paratypes. In general agreeing with holotype and exhibiting the following intraspecific variations: ventrals 167–177 notched with keels; subcaudals (males) 141–165, divided (females) 126–150, divided; dorsal scale rows in 13/15/16–15-13/11 rows of smooth, obliquely disposed scales; supralabials 7–8 with 5 th or 6 th supralabial being the largest; 5 th supralabial in contact with the eye; 4 th supralabial divided; loreal absent, infralabials 8–10; pre-suboculars 1–2; pre-ocular 1 (both left and right); post-oculars 2; sub-oculars absent; temporals 1+2 or 2+2 or 2+3; some specimens have a pronounced rostral appendage with scale divisions (1–2) or bumps on it.

Maxillary arch dentition (dissected from CESS043). Arched with a dip towards diastema; 17 teeth perpendicular to maxilla, curving inwards; prediastemal teeth 6, postdiastemal teeth 11, observable gradual tooth size increase in prediastemal tooth set with the largest teeth precursing diastema; diastema 4 tooth-sockets wide; suffixed with a set of 9 smaller, uniformly sized teeth followed by the last grooved pair of large teeth ( Fig. 6a ).

Variations in colour morphs. Dorsum uniform bright green to olive green; rostral, infralabials, venter yellowish green to light green at mid body; yellow to white ventral stripe along notched ventral keels; slight discolouration in the pre-ocular; inter-scalar skin white with black and white anteriorly-converging bars; white replaced by reddish brown inter-scalar skin posteriorly; eyes golden yellow with black speckles; concentration of black speckles both in the anterior and posterior ends of a horizontal pupil; slight discolouration around the pupil; tail, subcaudals green.

Hemipenis (dissected from CESS 066). Organ fairly short (4.5 mm long) and of medium width (4.1 mm wide); extending upto 2 subcaudal scales; unilobed, lobe head wide (4.3 mm), pedicel covered by cursive flounces; flounces appear clumped and sticking onto one another in clusters, probably a preservation artefact; larger spines towards the middle of the pedicel; spines appear cramped except the short spiky ones on top; those on the sides curved and clumped; in asulcate view, spiny flounces fully cover the entire length of the pedicel, no plain smooth patch visible; in sulcate view, sulcus spermaticus mildly visible, apparently centripetal, turning to the right.

Distribution and Habitat. This species is distributed in the Central Western Ghats in mid-elevation forests from 500 to 850 msl from Coorg to Agumbe-Kodachadri range in Karnataka ( Fig. 18 ). This species may be sympatric with A. malabarica sp. nov. in Coorg.

Figures

FIGURE 6. Ahaetulla lineages in Peninsular India and Sri Lanka showing side-by-side comparison of their superficial head morphology and maxillary dentition. (From the top) (a) Ahaetulla farnsworthi sp. nov. (b) A. isabellina comb. nov. (c) A. malabarica sp. nov. (d) A. borealis sp. nov. (e) A. nasuta (f) A. oxyrhyncha comb. nov. (g) A. sahyadrensis nom. nov. (h) A. travancorica sp. nov. (i) A. dispar & A. travancorica sp. nov. (j) A. perroteti (1) Ahaetulla farnsworthi sp. nov. (2) A. isabellina comb. nov. (3) A. malabarica sp. nov. (4) A. borealis sp. nov. (5) A. nasuta (6) A. oxyrhyncha comb. nov. (7) A. pulverulenta (8) A. sahyadrensis nom. nov. (9) A. dispar (10) A. travancorica sp. nov. (11) A. perroteti.

FIGURE 17. Images of Ahaetulla farnsworthi sp. nov.. Images of Holotype BNHS 3588 (CESS288). (a) Head lateral, (b) Head dorsal, (c) Ventral section, (d–f) Dissected hemipenis, (g) Whole specimen. Head lateral images of different individuals (live), (h) CESS158 from Kudremukh, (i) CESS157 from Kudremukh, (j) Body section showing interscalar colouration (CESS158), (k) Image of a live, uncollected individual from Agumbe (Photo: Shreeram M.V.) (Images a & b; d, e & f to scale, other images not to scale).

FIGURE 18. Habitat of Ahaetulla farnsworthi sp. nov. in Agumbe, Central Western Ghats (in Shimoga district, Karnataka State, India) showing tropical rainforest vegetation type.