Gloydius chambensis Kuttalam et al., 2022

Common name.

Chamba Pitviper

Type material examined.

Holotype. • HARC R 259 (DNA reference number 18.13), an adult male from Bhanjraru village, Chamba District, Himachal Pradesh, India, 32.8391°N, 76.1493°E, 1738 m altitude, found dead on road on 10 July 2018 by Kuttalam, Vishal Santra, John Benjamin Owens, Vipin Dhiman, Anita Malhotra, Nilanjan Mukherjee, Stuart Graham, and Anatoli Togridou. Paratype (s) not designated (Kuttalam et al. 2022).

Revised diagnosis.

A single loreal, wider than high; nasal completely divided, or partly divided below the naris; always two elongated preoculars, the lower narrower; a single supraocular; two postoculars, upper reaching onto top of head and touching the parietal, the lower can be described as postsubocular and touches, with its anterior side, the upper posterior edge of the third supralabial; rostral scale wider than high; two internasals wider than long; two prefrontals, ratio of length to width variable sometimes almost the same length; frontal bell-shaped, longer than wide; predominantly three, exceptionally one anterior and predominantly three or sometimes four posterior temporals; usually seven, rarely six or eight supralabials, always the third in contact with the eye; 15–18 circum-pileus scales; usually ten, sometimes nine, rarely eight sublabials, predominantly first three, sometimes first four, rarely only first two in contact with anterior submaxillars; two pairs of submaxillars, anterior usually twice as wide and 30–43 % longer than posterior; followed by three rows of paired gular scales, increasing in size posteriorly; anterior dorsal scales in 21, 23 or 25 rows, midbody dorsal scales in 21 rows, posterior dorsal scales in 17 rows; 0–5 preventrals; 157–164 ventrals (males 162–164, females 157–163); cloacal plate entire; 41–49 usually paired subcaudal scales (males 42–49, females 41–48), rarely up to two subcaudals undivided; sum of ventral and subcaudal scales 204–218 (males 211–218, females 204–217). Body compact, subcylindrical; tail short, ratio TaL / TL of 0.129 –0.202 (males 0.153 –0.202, females 0.129 –0.137); maximum recorded SVL in examined material: males 476 mm, females 527 mm; maximum recorded TaL in examined material: males 86 mm, females 84 mm; maximum recorded TL of examined material in males 562 mm, in females 611 mm.

Sum formula of dorsal scale reduction.

Variation in dentition.

Maxillary bone with two posteriorly curved fangs on each side. Main fang 4.98–5.45 mm in length, i. e., 26.0–28.4 % of skull length. Discharge orifice 0.79–0.81 mm in length, i. e., 14.9–15.9 % of fang length. Palatine bone with three or four posteriorly curved teeth slightly decreasing in size posteriorly. Pterygoid bone with nine posteriorly curved teeth, shorter than the palatine tooth, all nearly the same size. The posterior 60.9–61.1 % of the pterygoid bone is without teeth. Mandibular bone with 10 or 11 posteriorly curved teeth gradually decreasing in size posteriorly. The first two teeth closer together than the rest. Splenial either 67.1 % of length of angular or fused. The total length of splenial-angular complex spans 28.2–32.4 % of the mandibular bone. The dental is 38.7–39.6 % as long as the mandibular bone. The complete skull of the specimen BMNH 1898.5.17.4 is presented in Fig. 10.

Variation in life colouration and pattern.

Dorsal ground colour can vary from Cinnamon-Drab (Colour 50) to Smoke Gray (266), with 32–46 very thin Sepia (279) coloured irregular cross bands their anterior borders sometimes edged with Cream White (52), the bands may be broken on the back and offset from each other; tail with 10–12 thin Sepia (279) crossbands; a row of small, irregular Sepia (279) - coloured and Cream White (52) - bordered spots runs along the outer edge of the ventrals; dorsal and lateral head same as dorsal body colour or Pale Neutral Gray (296) and densely mottled with Sepia (279); a Sepia (279) coloured postocular stripe with a mainly straight thin Cream White (52) lower margin runs from the posterior border of the eye to the posterior edge of the mandible, the height of the anterior part of the postocular stripe is variable and can cover up to two-thirds of the anterior lower temporal scale; neck with two paravertebral and two lateral wavy Sepia (279) coloured stripes and a very thin and short one in the middle of the dorsal head; venter with a colour gradient that becomes darker towards the tail; throat Pale Neutral Gray (296) coloured, gulars mottled with Dark Grayish Brown (284); subsequently, the venter ground colour changes gradually to Light Neutral Gray (297) and shows heavy Sepia (279) mottling; tail tip lighter. Examples of variation in the colouration and pattern of live individuals; see Fig. 11.

Distribution.

Gloydius chambensis is a narrowly distributed species of pitviper endemic to the western Himalaya, originally known only from the Chamba District of Himachal Pradesh, India. Confirmed records based on genetic and morphological data include the type locality Bhanjraru (1738 m) and Teppa (2543 m) in the Churah Valley. However, our results have significantly expanded the known distribution of the species. Based on a combination of distributional data and newly generated genetic evidence from museum specimens (BMNH 1898.5.17.4 –5 and NHMW 17079: 1), the known range of G. chambensis has been extended westward by approximately 260 km into the Kashmir Valley, specifically to Srinagar, where NHMW 17079: 1 was collected. This extension suggests that the species may occupy a polygonal range of up to 16,000 km 2 (less when considering suitable habitats only; Fig. 9).

Habitat and ecology.

Gloydius chambensis occurs primarily in alpine scrub and temperate pine forests, often in areas with thick pine needle litter on the forest floor. The terrain is typically rocky and interspersed with boulders and rock faces, providing natural shelter and basking spots. It inhabits an elevational range of ~ 400–2500 m in the lower montane to subalpine transition zone (Fig. 11), although most records for G. chambensis fall within the lower temperate zone (~ 1700 m; Kuttalam et al. 2022), particularly in the Churah Valley.

Conservation.

Despite this ecological specificity and documented human interaction (Kuttalam et al. 2022), the species remains unassessed by the IUCN Red List and unprotected under national conservation frameworks. The combination of its narrow range (but see the specimen from Kashmir Valley, NHMW 17079: 1), morphological and genetic distinctiveness, and known anthropogenic threats such as forest degradation, increasing road and rural development, underscores the urgent need for targeted conservation measures. These should include especially habitat preservation, ecological monitoring, community engagement programs, and formal threat assessment to support its inclusion in conservation priority lists.