Lycodon mackinnoni Wall, 1906

Nawani, Swati, Deepak, V., Gautam, Kumudani Bala, Gupta, Sandeep Kumar, Boruah, Bitupan & Das, Abhijit, 2021, Systematic status of the rare Himalayan wolf snake Lycodon mackinnoni Wall 1906 (Serpentes: Colubridae), Zootaxa 4966 (3), pp. 305-320 : 309-313

Lycodon mackinnoni Wall, 1906 ( Fig. 2–6 )

Chresonymy. Lycodon mackinnoni — Wall (1906: 29), Smith (1943: 263), Lanza (1999: 99), Whitaker & Captain (2004: 24), Bahuguna (2010: 481), Wallach et al. (2014: 395), Das & Das (2017: 166), Ganesh et al. (2020: 75) Ophites mackinnoni — Wall (1923:614)

Common Name. Himalayan snake ( Wall, 1906), Mackinnon’s Wolf Snake ( Wall, 1906; Uetz et al. 2020; Smith, 1943), Mussoorie wolf snake ( Bahuguna, 2010), Himalayan wolf snake ( Manhas et al. 2015)

Holotype. BMNH 1946.1 .13.81 adult female, in “ Neighbourhood of Mussoorie ”, Uttar Pradesh (presently Uttarakhand), India (roughly 30.4595° N, 78.0715° E).

Referred material. WII-ADR197, adult female, from Dhobhighat (30.4690°N, 78.0338° E, 1659 meter above sea level (m asl)), near Binog Wildlife Sanctuary, Mussoorie, Uttarakhand, India, collected by Kuldeep Rawat on 20 May, 2019 at 2300 hrs .

Description of adult female. We provide a detailed description of WII-ADR197 as the first description of a female individual of Lycodon mackinnoni . See Table 2 for the morphometric and meristic data. The specimen is in good condition, slightly desiccated. Slender body, generally oval-shaped in cross-section, with rounded dorsum, widest approximately at midbody, tapering posteriorly. Head suboval when viewed from the top, longer than wide, moderately distinct from the neck, sides convex, slightly converging towards the snout. Snout subovoid when viewed from the top, slightly projecting beyond the lower jaw. In lateral view, head almost flat from back to the anterior part of the eye, obtusely projecting towards the snout. Canthus rostralis indistinct in cross-section. Loreal region convex in lateral cross-section. Rostral in dorsal view partially visible, two times wider than long; frontal hexagonal, slightly longer than wide, lateral edges diverging anteriorly, more than half of the parietal height, width almost equal; parietals longer than wide, overlapping medially, subhexagonal, in contact with frontal, supraocular, two upper temporals, contacting with upper and lower postocular in right side only; prefrontal subequal in width and length, subpentagonal, slightly longer and broader than internasals. Nasal divided, anterior nasal is double in height to posterior nasal, anterior nasal subpentagonal, posterior nasal subquadrangular, in contact with the first supralabial; internasal subpentagonal, nearly equal in height and width. Loreal subhexagonal, higher than wide; touching preocular, internasal, prefrontal and posterior nasal. Supraocular slightly higher than wide in the right, merged with first preocular scale in the left side. One preocular on both side, subpentagonal. Postocular two in the right side, one in left, upper postocular fused with supraocular. Subcircular naris, dorsally visible, nostril opening covered much of the anterior nasal scale; eight supralabials on each side; 3 rd, 4 th and 5 th entering orbit, 1 st –3 rd in contact with loreal, 6 th with lower postocular, 8 th contacting posterior lower temporal, 6 th is the highest among all, 7 th is the widest; two anterior temporals and three posterior temporals on each side. Both anterior are almost equally wider. Eye lateral with rounded pupil, longitudinal diameter half of the distance between eye and nostril, the horizontal distance between the two eyes is almost equal to the distance between eye to snout; Mental subtriangular, wider than long. Nine infralabials (ILs), first pair longest and in midline contact, 6 th is widest among all, 9 th is the smallest. Two pairs of genials, nearly equal in size, 1 st – 5 th ILs in contact with anterior genials, in right, while in left 1 st – 4 th in contact, 5 th – 6 th with posterior genial’s contact.

Dorsal scale 17:17:15; smooth throughout the body, dorsal scales just behind the head slightly smaller than at midbody, no apical pit present, dorsal scale 17 till 115 ventral, in right side, reduction from 17 to 16 DSR is due to the fusion of 3 and 4 row at 116 ventral, reduction from 16 to 15 DSR is due to fusion of 3 and 4 row at 122 ventral scales maintained to vent. Ventral scales 186; not angulate laterally, anal divided; subcaudals 52, divided; tail not pointed, tail base subtriangular in cross-section.

Dorsum greyish - brown with a network of approximately 63 white bands from just behind the head to vent. The bands are distributed profusely, connected laterally, anteriorly more spaced than posterior, in tail region bands are a little indistinct and more closer. First two rows of dorsal scale are margined with pastel white with dark brown centre. Ventrals mostly pale with light brownish edges, preventrals mostly pale with isolated and irregular light brown blotches.

Head greyish brown, white mottling on parietals lateral side, white blotch where parietal and frontal meets medially; ventral side of the head pale; First three ILs and mental with light brown mottling.

Comparison with holotype. The new specimen matches the holotype with the following exceptions. In WII-ADR197, loreal scale is present which was reported to be absent in Wall (1906). Subsequent reports of the species ( Manhas et al. 2015; Faiz et al. 2018; Jablonski et al. 2019) reported presence of loreal scale as a character. This is quite intriguing for the fact that loreal is present in the topotypic material ( Fig. 4E ). We suspect that since the specimen submitted to Wall (1906) was “mutilated” (sic Wall, 1906) on the head, thus there may be a mismatch. As we have observed the type it was difficult to ascertain the presence of loreal scale from the desiccated head scales ( Fig. 5 . However, in the place of loreal scale we noticed a long space inbetween preocular and the nasal. The new specimen differs in having one left postocular, while there are two in the holotype. BMNH 1946.1.13.81 has 8,7 SLs, 2+2 anterior temporals (AT) and posterior temporals (PT) while the new specimen has 8,8 SLs, 2+3 AT and PT. Moreover, holotype has separate prefrontal and internasal on the right side while on the left side they are fused. The rest of the characters match with the holotype.

Natural history and habitat: On the 20 th of May at 23:00 hrs, a gravid female individual was observed active on the ground along a foot trail on a ~50 o slope. The snake was found active at 16.7 oC ambient temperature and relative humidity of 48.1%. The area was a part of south-facing slope of the outer Himalayas dominated by Quarcus leucotricophora (Camus) and weedy Ageratina adenophora (Spreng) and is greatly modified for human and grazing use. Ground vegetations are sparse and shunted. The area was mostly rocky and a considerable part of it was in the form of limestone. The soil in the region is generally medium loam but its composition, depth, moisture and humus content varies considerably from place to place depending upon aspect, slopes and soil cover. Lycodon mackinnoni is a montane and generally nocturnal species. It is a low to medium (783–2000 m) hill dwelling species ( Faiz et al. 2018; Smith 1943). It inhabits the medium loam, low bushes, Banj oak forests, Chir pine forests and crop land ( Faiz et al. 2018; Jablonski et al. 2019). The snake was docile and never attempted to bite. The sighting confirmed the terrestrial habits of the species. On the 3 rd of June 2019 the snake laid four eggs in captivity. The eggs ranged from 19.2– 23.4 mm length x 9.0 – 9.7 mm width. Syntopic reptilian fauna observed in its habitat included Sibynophis collaris (Gray, 1853) , Gloydius himalayanus (Gunther, 1864) , Herpetoreas platyceps (Blyth, 1854) , Boiga multifasciata (Blyth, 1861) , Japalura kumaonensis (Annandale, 1907) and Asymblepharus himalayanus (Gunther, 1864) .

Conservation status. Biodiversity values of the Himalayan region are under threat from deforestation, development projects, urbanization and climate change ( Bawa & Kadur, 2013). The record of Lycodon mackinnoni from its type locality after a long gap was a matter of delight. The record from close to BWLS indicates the availability of similar and safer habitats where the species is likely to occur. Being situated near the famous tourist destination Mussoorie, Binog attracts tourists throughout the year which often causes vehicular traffic, pollution and other tourism-related activities in the sanctuary. Such kind of human intervention may be detrimental for the Himalayan endemic species like L. mackinnoni which is assigned as schedule IV according to Wildlife (Protection) Act 1972 of the Parliament of India. A detailed status survey and further research on the biological aspects are needed to develop a comprehensive action plan for this rare species.

Figures

FIGURE 2. Maximum likelihood phylogeny showing relationships of Lycodon mackinnoni with other Lycodon species. Samples in blue are sequences generated from India. ML bootstrap support and BI posterior probability are shown at each node. Incongruent nodes between the two phylogenies are shown with a “-”.

FIGURE 3. Lycodon mackinnoni (WII- ADR197). A: in-situ, B: ex-situ. (Photos by Abhijit Das).

FIGURE 4. Preserved specimen of Lycodon mackinnoni (WII- ADR197). A: Dorsal view and B: Ventral view of full body, C: Dorsal view of head, D: Ventral view of head and E: Lateral view of head.

FIGURE 5. Holotype of Lycodon mackinnoni (BMNH 1946.1.13.81). A: Dorsal view and B: Ventral view of full body, C: Dorsal view of head, D: Ventral view of head and E: Lateral view of head.

FIGURE 6. Drawing of Lycodon mackinnoni reproduced from Wall’s (1906) original description. Note the missing loreal scales.