Gloydius himalayanus (Günther, 1864)

Gloydius himalayanus (Günther, 1864): 393, pl. 24, figs A, A'.

Common name.

Himalayan Pitviper.

Type material.

The original description of Halys himalayanus Günther, 1864 is based on two syntypes originating from " Garhval, Himalaya (altitude 9000 feet) ". Both specimens are preserved in the collection of the Natural History Museum, London: BMNH 1946.1.19.64 (Figs 1, 12; formerly BMNH 1860.3.19.1358), collected by the German explorers, the von Schlagintweit brothers; and BMNH 1946.1.18.75 (formerly BMNH 1860.3.19.1189), originating from the collection of the Danish physician and biologist Theodore Edward Cantor.

On behalf of the British East India Company (BEIC), and with financial support of the Prussian king Frederick William IV, and the monarch Maximilian II of Bavaria, the brothers Hermann, Adolf, and Robert von Schlagintweit undertook a four-year scientific expedition from 1854–1858 to explore the Indian subcontinent and its northern high mountain regions. They travelled, sometimes together, but also on separate routes, through India and the Himalaya up to the Tibetan plateau [Schlagintweit-Sakülünski 1871; on the controversial debate about the achievements of the expedition see Brescius (2015) and Kleidt (2024)].

The natural history objects collected during the von Schlagintweit expedition were the property of the BEIC but were brought to Berlin for scientific analysis and were then to be successively returned and reintegrated in the BEIC collections in London. Between 1858 and 1859, an unknown number of stuffed animals, as well as wet preserved reptiles and fishes were transferred from Berlin to the India Museum of the BEIC whose whereabouts are now unknown according to Kleidt (2024). Sharpe (1906) mentioned that the transfer of part of the India Museum collection to the BMNH began in 1860 (1859 according to Archer 1962: 63), but the final incorporation of the old BEIC collection took place in 1880 (1879 according to Kleidt 2015). Additionally, Günther’s (1860) overview of the herpetofauna of the Himalaya, which includes 118 listed specimens of amphibians and reptiles referable to material collected by the von Schlagintweit brothers, clarifies that objects from the expedition, including documents stating localities and altitudes at which each specimen was obtained, had already been handed over from the Museum of the BEIC specifically to him for examination (i. e., no later than May 1860 when his paper was published). Many of these specimens are subsequently listed in the published catalogues of the holdings of the herpetological collection of the BMNH (see Boulenger 1885, 1887, 1889, 1893, 1894, 1896). In his 1860 paper, Günther at the time working on the classification of the BMNH snake collection, mentioned also the von Schlagintweits’ specimen, which later served as one of the two syntypes of Halys himalayanus for the first time under the name " Trigonocephalus affinis " (Günther 1860: 164, 167, 172). It is not documented in the records of the herpetological department of the NHM London which of the von Schlagintweit brothers collected the specimen, and Günther’s (1860) paper, and his (1864) original description, also provide no clue.

According to the itinerary and map of the routes taken by the von Schlagintweit brothers in the western Himalaya, it becomes clear that only Adolf and Robert had travelled in Kumaon and Garhval between early July and mid-October 1855 (Schlagintweit et al. 1861 a: 17 ff.). From the listed stations no. 50–55 visited in " Kămáon and Gărhvál " only the following are situated in Garhval as defined at that time by the von Schlagintweit brothers: " Mána (in Vishnuganga valley, two miles north of the Hindi temple Bádrinath, 30°47'0"N, 79°20'50"E, 10,670 feet) ", " Mána Pass (two days journey north of Mána, 31°5'0"N, 79°23'25"E, 18,852 feet) ", " Ussílla (highest village in the valley of Tons, 31°7'40"N, 78°18'10"E, 8940 feet) ", " Măssúri, Banóg Hill (station, 30°28'30"N, 77°59'58"E, 7549 feet) " (Schlagintweit et al. 1861 a: 197 ff., 1861 b: map a, 1). Based on the altitude of 9000 feet [2743 m] given by Günther (1860, 1864), the later syntype specimen collected by the von Schlagintweit brothers could have been found in or around " Ussílla ". This place is also mentioned for plants collected in early October 1855 by the von Schlagintweit brothers as " Usilla in the Sons [sic, Tons] valley " by Klatt (1880: 369). If the von Schlagintweit’s type specimen was indeed from " Ussílla " [also known as Oshól, a village no longer existing on the right bank of the Tons [Tonse or Supin] River Valley, near today’s Osla village in the southern Supin Range, Uttarkashi District, Uttarakhand State, India], then it was collected by Adolf von Schlagintweit, who was the only one of the brothers to visit this location during his second journey to Tibet on his return to Garhwal between 6–9 October 1855 (Schlagintweit et al. 1861 a: 19).

Similar to the von Schlagintweits’ material, the second syntype of H. himalayanus was donated indirectly to the British Museum (Natural History) from Theodore Edward Cantor’s collection. Between 1842 and 1854, Cantor sent several general collections to the Museum of the British East India Company (India Museum), London, and many of the natural history specimens were transferred to the BMNH in 1860 (Boulenger 1906; Whitehead and Talwar 1976). Among these objects was probably Cantor’s specimen, which later served as second syntype and was registered by Günther on 19 March 1860, the month of Cantor’s death, under the number 1189. As mentioned above, Günther (1860) only listed the specimen from the von Schlagintweits collection in his treatise on the herpetofauna of the Himalaya. The first part of the Proceedings of the Zoological Society of London, which contains Günther’s work, was published between February and May 1860 (Duncan 1937), and Cantor’s specimen probably reached Günther’s hands too late to be considered.

Cantor worked as a physician in the service of the British East India Company based in Calcutta [Kolkata, West Bengal State, India], where he arrived in 1835. His duties took him to China (Chusan), the Malay Peninsula (Provinces of Malacca and Wellesley, Penang, and Singapore), and Bengal (Sundarbans, Ganges-Brahmaputra Delta), where he had the opportunity to make substantial zoological and botanical collections. It is documented that Cantor was posted to NW India twice during the First and Second Anglo-Sikh War for his military service in field hospitals from 1845–1846 and from 1848–1849 (Adler 2007, 2016; Archer 1962). It is possible that it was during these visits that he obtained the specimen that was later to become the second syntype of H. himalayanus.

Because of the better documented historic circumstances (route of travel) for the syntype collected by the von Schlagintweits, and in agreement with Art. 74.7 of the Code (ICZN 1999), we here designate BMNH 1946.1.19.64 as lectotype of Halys himalayanus Günther, 1864 to introduce a standard of application for the species group name himalayanus Günther using a single name-bearing specimen.

Type material examined.

Lectotype. • BMNH 1946.1.19.64, an adult male from " Garhval, Himalaya (altitude 9000 feet) " (Uttarkashi District, Uttarakhand State, India; see above for further discussion on the possible locality), collected by the brothers Adolf or Robert von Schlagintweit (Figs 6 A, 12, 13). Paralectotype. • BMNH 1946.1.18.75, an adult male, collector (s) not documented, ex Theodor Edward Cantor collection; other data as for the lectotype.

Description of the lectotype.

Adult male, indicated by the presence of hemipenes, in situ reaching level of 18 th subcaudal scale; 1 / 1 loreal, slightly higher than wide; nasal scale completely divided; 2 / 2 elongated preoculars, the lower one much narrower; 1 / 1 supraocular; 2 / 2 postoculars, upper scarcely reaching onto top of head, the lower can be described as postsubocular, because it extends below the eye, up to the level of the end of the third supralabial; rostral scale wider than long; two internasals much wider than long; two prefrontals, slightly longer than wide; frontal bell-shaped, 22 % longer than wide; 3 / 3 anterior temporals upper two very small, and 3 / 3 posterior temporals of similar size, the lower one in contact with the second last supralabial; supralabials 7 / 7, second last twice as high as the previous one, in contact with lower posterior temporal, 3 rd / 3 rd in contact with the eye; pit opening as long as the horizontal diameter of the eye and encircled by 3 / 3 scales; 18 circum-pileus scales; 10 / 10 sublabials, first four in contact with anterior submaxillars; two pairs of submaxillars, anterior approx. twice as wide and 50 % longer than posterior; followed by four rows of paired gular scales, slightly increasing in size posteriorly; dorsal scales in 21-21 - 17 rows, strongly keeled, except the outer row, which is smooth, paired apical pits on some dorsals, very weakly developed; four preventrals; 162 ventrals; cloacal plate entire; 50 / 51 paired subcaudal scales. Body compact, subcylindrical; tail short (TaL / SVL 0.145); SVL 537 mm; TaL 91 mm, head length measured from tip of snout to posterior border of parietals 17.5 mm, head length measured from tip of snout to posterior edge of mandible 28.5 mm, head width 16.4 mm.

Dorsal scale reduction formula.

Dentition.

Maxillary bone with two posteriorly curved fangs on each side. On left side, the lateral main fang is loose, both teeth are not connected to the maxilla on right side. Behind each main fang are 7 / 8 replacement fangs at different growth stages. Main fang 6.44 mm in length, i. e., 31.52 % of skull length. Discharge orifice 0.97 mm in length, i. e., 15.06 % of fang length.

Palatine bone with 3 / 3 posteriorly curved teeth slightly decreasing in size posteriorly. Teeth I and II loose on left, teeth I and III on right side. Lateral to each palatine tooth is a single replacement tooth at different growth stages.

Pterygoid bone with 9 / 9 posteriorly curved teeth, shorter than the palatine tooth, all nearly the same size. Teeth II, IV, VI and VIII loose on left side as well as on right side. The posterior ~ 64 % of the pterygoid bone is without teeth.

Mandibular bone with 11 / 11 posteriorly curved teeth gradually decreasing in size posteriorly. The first two teeth closer together than the rest. Medial to each mandibular tooth are two replacement teeth in different growth stages. Teeth II, III, V, VII, IX and XI loose on left side. Teeth II, IV, VI and VIII loose on right side. Splenial 93 % of length of angular, latter overlaps splenial with 8.19 % of its total length. The complete skull of the lectotype BMNH 1946.1.19.64 is presented in Fig. 13.

Colouration and pattern.

Colouration after ~ 170 years preservation in ~ 70 % ethanol was recorded as follows: dorsal ground colour Light Neutral Gray (Colour 297), with 40 Pale Neutral Gray (296) irregular bands on body, one to two dorsal scales long and ten bands on tail, the anterior edge of dorsal bands shows thin Dark Grayish Brown (284) borders; all dorsal scales show a Dark Grayish Brown (284) mottling, which condenses dorsoventrally; dorsal and lateral head with same ground colour as dorsal body and densely mottled with Dark Grayish Brown (284); a wide Sepia (279) postocular stripe from the posterior border of the eye to the angle of the mouth, whose lower edge is bordered by a Dark Grayish Brown (284) wavy, narrow line; lower parts of posterior supralabials Pale Buff (1) and heavily mottled with Dark Grayish Brown (284); Venter with a colour gradient that becomes darker towards the back. Throat Pale Buff (1) coloured submaxillars and gulars mottled with Dark Grayish Brown (284); sublabials with an irregular Fawn Colour (258) pattern; in the further course, venter changes gradually from True Cinnamon (260) with heavy Dark Grayish Brown (284) mottling via Burnt Sienna (38) to Maroon (39); the dark ventral parts of posterior third of body and ventral tail are Pale Buff (1) mottled; tail tip Light Buff (2) coloured. Examples of variation in the colouration and pattern of live individuals; see Fig. 14.

Variation.

The paralectotype and additional examined material agree well with the lectotype in general appearance. For differences based on sexual dimorphism, morphometrics and scalation we refer to Tables 3, 4.

Sum formula of dorsal scale reduction in males.

Sum formula of dorsal scale reduction in females.

Variation in dentition.

Maxillary bone with two posteriorly curved fangs on each side. Main fang 3.89–6.44 mm in length, i. e., 23.95–31.52 % of skull length. Discharge orifice 0.52–0.97 mm in length, i. e., 12.9–15.1 % of fang length. Palatine bone with three posteriorly curved teeth slightly decreasing in size posteriorly. Pterygoid bone with 7–10 posteriorly curved teeth, shorter than the palatine tooth, all nearly the same size. The posterior 59.7–66.3 % of the pterygoid bone is without teeth. Mandibular bone with 10–12 posteriorly curved teeth gradually decreasing in size posteriorly. The first two teeth closer together than the rest. Splenial either 93.0 % of length of angular or fused. The total length of splenial-angular complex spans 22.9–29.0 % of the mandibular bone. The dental is 36.1–39.3 % as long as the mandibular bone.

Variation in life colouration and pattern.

Dorsal ground colour varies from Drab (Colour 19) to Cinnamon-Drab (50), Drab-Grey (256) or Lavender (202), with 29–40 Olive-Brown (278), Warm Sepia (40), or Dusky Brown (285) irregular bands on dorsal body. The bands can vary from one to three dorsal scales in length, can be interrupted vertebrally or can be broken in transverse rows of three roundish blotches. The anterior edge of the bands or blotches often shows a thin Dark Grayish Brown (284) border, whereas the upper row of blotches is separated by Pale Buff (1) coloured interspaces, especially in juveniles. All dorsal scales show a Dark Grayish Brown (284) mottling, which condenses dorsoventrally. Ventrolaterally, sometimes a small irregularly shaped Dusky Brown (285) spot, which is outlined with Smoky White (261), is present between the bands or the lower row of roundish blotches. Dorsal tail with 7–10 thin Olive-Brown (278) or Warm Sepia (40) coloured irregular bands. Tail tip lighter.

Dorsal head with same ground colour as dark body bands or blotches; canthus rostralis and upper temporal region usually lighter; neck usually with two paravertebral and two lateral Dark Grayish Brown (284) lines starting approximately at the level of the posterior edge of mandible and extending to the anterior border of first band or blotch; a wide Dusky Brown (285) postocular stripe runs from the posterior border of the eye to the angle of the mouth, whose lower edge is bordered by lighter Pale Buff (1) coloured wavy, narrow line, anterior part of postocular stripe covers more than two thirds of the anterior lower temporal scale; head sides including upper labials Pale Buff (1) coloured and heavily mottled with Dark Grayish Brown (284); venter with a colour gradient that becomes darker towards the tail. Throat Pale Buff (1) coloured, submaxillars and gulars mottled with Dark Grayish Brown (284); sublabials Pale Buff (1) coloured, sometimes with large irregular Dark Grayish Brown (284) blotches; in the further course, venter changes gradually from Pale Buff (1) via Pale Neutral Gray (296) or Drab-Gray (256) to Smoke Gray (268) or Olive brown (278) and is completely heavily mottled with Dark Grayish Brown (284).

Remarks on common and scientific name.

Wall (1910: 66) suggested the English common name " Brown Himalayan Viper ", although we recommend using the more precise name " Brown Himalayan Pitviper ". In Kashmir (where G. chambensis or G. hazarensis sp. nov. may also be present according to this study; Fig. 9), the pitviper is known as " pohur " by natives (Wall 1910). The epithet himalayanus has a long tradition in herpetology and is used as a reference to the species’ occurrence in the Himalayan region; it has been applied to several amphibians and reptiles from the area, e. g., Duttaphrynus himalayanus (Günther, 1864), Tylototriton himalayanus Khatiwada et al., 2015, Cyrtopodion himalayanus Duda & Sahi, 1978, Ablepharus himalayanus (Günther, 1864), Rhabdophis himalayanus (Günther, 1864) and Protobothrops himalayanus Pan et al., 2013.

Distribution.

Probably the first brief description of a venomous snake originating from the Himalaya that can be attributed to the G. himalayanus complex was given in a footnote in Vigne’s travelogue through Kashmir etc., published in 1842. Based on the results presented here (Fig. 9, Suppl. material 1: table SS 3), this species is known exclusively from the Indian Himalaya. The westernmost localities include Dumas, Bairagarh in India, as reported by Kuttalam et al. (2022), while the easternmost locality is Lingurani (Captain, pers. comm. 2024). We estimate the polygonal range of the species to be ca 56,000 km 2. However, we cannot exclude that G. himalayanus (sensu stricto) also occurs west of Himachal Pradesh e. g., in Kashmir. Therefore, until we have data to the contrary, we propose to list specimens from this transitional zone as Gloydius cf. himalayanus.

Habitat and ecology.

According to our data, the species inhabits elevations between ca 1000 and 3500 m in subtropical montane to subalpine zone (with a dubious record of ~ 4877 m introduced by Sclater (1891), see comment above on the distribution of the G. himalayanus complex) in northwestern India. The species prefers montane environments and is typically associated with coniferous forests, rocky slopes, alpine meadows, and areas with abundant leaf litter with cover such as logs, stones, and crevices (Manhas 2020; although the species affiliation of this population is unclear; see Fig. 14 and Suppl. material 1: table SS 3). It exhibits a generalist microhabitat use but relies on thermally buffered refugia. Early reports from Kashmir, e. g., Alcock (1898), Wall (1899), Fenton (1910), and Dattatri (1985) described this snake as " very common to swarming ", especially in the Liddar River Valley where it could be found almost everywhere. In Uttarakhand it is widely distributed and not difficult to find in suitable habitats in the Dehradun and Uttarkashi districts. Observations indicate that its presence is more frequent within protected areas, although the species can also occur near human settlements where the habitat is suitable.

Conservation.

Gloydius himalayanus is currently listed as Least Concern (LC) on the IUCN Red List (Limbu and Ghosh 2022), primarily due to its presumed wide distribution across the Southern Himalaya and its presence in multiple countries and protected areas. However, the taxonomic revision presented here significantly narrows the species’ confirmed range, restricting it to India. Consequently, a reassessment of its global conservation status is necessary. Although G. himalayanus is not listed in the CITES Appendices, it is legally protected in India under Schedule II of the Wildlife (Protection) Act, 1972, amended 2022. Despite its previous broad classification, the species faces several regional threats, including persecution (often fuelled by fear of snakebites), road mortality linked to expanding infrastructure, and habitat degradation resulting from agricultural activities and tourism-related construction. Pushpangadan et al. (2014) report that in some northwestern Indian rural communities, dead specimens or their body parts (e. g., fat and venom) are used for food or traditional medicines. Climate change may also pose an additional future threat by altering high-elevation habitats, although the extent of its impact remains unclear. While no species-specific conservation measures are currently in place, G. himalayanus benefits from some in-situ protection within Himalayan protected areas (e. g., Prasad et al. 2021).