Gloydius swild Shi & Malhotra, 2021

Shi, Jing-Song, Liu, Jin-Cheng, Giri, Rohit, Owens, John Benjamin, Santra, Vishal, Kuttalam, Sourish, Selvan, Melvin, Guo, Ke-Ji & Malhotra, Anita, 2021, Molecular phylogenetic analysis of the genus Gloydius (Squamata, Viperidae, Crotalinae), with description of two new alpine species from Qinghai-Tibet Plateau, China, ZooKeys 1061, pp. 87-108 : 87

Gloydius swild Shi & Malhotra sp. nov.

Etymology.

The new species from Heishui, Sichuan is named after the Swild Group (Southwest Wild, http://www.swild.cn/), who discovered the new species and collected the first species during an expedition to the Dagu Holy-glacier, Heishui, Sichuan. The common name of G. swild sp. nov. is suggested as "Glacier pit viper" in English, and "Bīng Chuān Fù ( 冰川蝮)” in Chinese.

Type series.

Gloydius swild sp. nov, holotype, IVPP OV2725 (G2, Figs 1 , 3 ), adult female, collected from Heishui, Aba, Sichuan (32.23°N, 102.80°E, 2940 m), on 23 July, 2017, by the senior author; paratype, IVPP OV 2726, adult female, the same locality as the holotype, collected by Jia-Wei Wu (chief executive officer of SWILD Group).

Diagnosis.

Gloydius swild sp. nov. differs from other congeneric species in the following characteristics: i) the narrower postorbital stripe, ii) a pair of round spots on the parietal scales; iii) the absence of the black spots on the lateral body; iv) 21 rows of mid-body dorsal scales; v) a pair of arched stripes on the occiput; vi) 168-170 ventral scales, and vii) 43-46 subcaudal scales.

Morphologically, Gloydius swild sp. nov. is quite similar to G. angusticeps , but differs by the narrower, straight bordered brown postorbital stripe (versus wider postorbital stripe with dentate lower border in G. angusticeps ). G. swild sp. nov. differs from G. strauchi , G. huangi , and G. rubromaculatus by the narrow triangular head from dorsal view (versus spoon-shaped head in above-mentioned species), from G. monticola by having seven supralabials (versus always six supralabials) and more subcaudal scales (43-46 pairs versus always fewer than 30 pairs of subcaudal scales), from G. qinlingensis and G. liupanensis by its dark greyish brown background dorsal color (versus yellowish-brown body colour) and lacking a lateral white line on each side (versus possessing a lateral white line on each side), from G. himalayanus by possessing an indistinct canthus rostralis (versus very distinct canthus rostralis; Gloyd and Conant 1990).

Description of the holotype.

Gloydius swild sp. nov., IVPP OV 2725, adult female, a slender pit viper with a total length of 529.5 mm (SVL 462 mm and TL 67.5 mm), preserved in 75% ethanol (Fig. 1 ).

The head is slender and narrow triangular shaped in dorsal view, distinct from the neck. Canthus rostralis not distinct. The head is 20.8 mm in length, 12.2 mm in width and 6.6 mm in depth.

Scalation. Rostral scale slightly up-turned, visible from dorsal view; nasal divided, anterior part larger; seven supralabials on both sides: second smallest, not reaching the pit; third highest, not touching the bottom of orbit on the left (separated by one small subocular) while touching the bottom of the orbit on the right; fourth longest, not touching the orbit; three preoculars, two postoculars, inferior one touching the top of the third supralabials, forming the bottom margin of the orbit; two rows of temporals: 3+5/2+4 (L/R); infralabials 10, first pair in contact behind the mental; second, third and fourth pairs meet on the chin shield; chin shield is rhomboidal in shape, the posterior chin shield comprises two pairs of scales, forming the mental groove (Fig. 3D-F ). Dorsal scales in 21-21-15 rows, keeled except for the first scale row bordering the ventral scales; ventral scales 170 (excluding four preventral scales); anal plate single; subcaudals 46, in pairs.

Coloration. Gloydius swild sp. nov., eye light greyish brown on the upper half while black on the bottom half, pupil black, vertical with light yellow margins; postorbital stripe relatively narrow, only half the width of the anterior temporals, greyish brown and white bordered on the lower edge, extending from the posterior orbit to the lateral surface of the neck; supralabials and infralabials greyish white, scattered with large irregularly sized, black blotches, rendering the lateral head granitoid. One black Ω-shaped mark on the anterodorsal head, covering the posteromedial part of prefrontals, the anterior and lateral part of the frontals and the anterior part of the parietals. The infralabials are bordered with yellow on the lower edge.

The body coloration is dark blueish-grey, with two rows of irregular black X-shaped or C-shaped crossbands on the mid-body, each covering about 10 dorsal scales (or more), separated by a gap of one or two dorsal scales vertically, sometimes in contact with the adjacent ones forming zigzag stripes, but hardly merged on the medial dorsal line, extending laterally to one or two dorsal scales from the ventrals. Ventral scales light grey, scattered with dense irregular black blotches, rendering the ventral scales granitoid. The tip of tail is bony, similar to the main body in coloration on both ventral and dorsal sides (Figs 1C, D , 3D-F ).

Infraspecific morphological variation.

Despite the inconspicuous variation in the coloration among the type series of G. swild sp. nov., the scalations vary considerably between the two specimens. The range of the temporal scales of the holotype (IVPP OV 2725) is 3+5 on the left side but 2+4 on the right side, while in the paratype (IVPP OV 2726), the temporal scales are displayed as 2+4 on both sides. Ventrals range from 168-170 in females (n = 2), while range from 43-46 in females (n = 3, including one shed skin from the wild). Total length ranges from 529.5-629.1 in adult females. The infralabials of the paratype lack the greyish-yellow margins seen in the holotype.

Distribution and ecology.

Gloydius swild sp. nov. has been found in east part of Qinghai-Tibet plateau and Hengduanshan mountains, Heishui country, north Sichuan, about 15 km away from Dagu Holy-glacier National Geological Park, from along the route of Red Army’s long march (from June to August, 1935). They were found on or under the rocks (especially near the vegetations) on sunny slopes (Figs 6 , 7C ).

Viviparous reproduction.

One adult female (Holotype) was collected when pregnant, gave birth to eight neonates (including a couple of conjoined twins) on September 20th, 2017 in captivity. The weight of the normal neonates ranged between 3.00-3.45 g (3.01, 3.22, 3.22, 3.23, 3.28, 3.45, average = 3.235, n = 6). The weight of the conjoined twins was 2.86 g (weighed after the first shedding).

Figures

Figure 1. Gloydius lipipengi sp. nov. (A, B IVPP OV 2720, holotype) and Gloydius swild sp. nov. (C IVPP OV 2725, holotype, D IVPP OV, 2726, paratype) in life, not to scale.

Figure 3. Head squamation of Gloydius lipipengi sp. nov. (Holotype, IVPP OV 2720: A lateral view B dorsal view C ventral view) and G. swild sp. nov. (Holotype, IVPP OV 2725: D lateral view E dorsal view F ventral view). Scale bar: 10 mm.

Figure 6. Type localities of Gloydius lipipengi sp. nov. (red triangles) and G. swild sp. nov. (black triangles), with the collection localities of some other congeneric species.

Figure 7. The habitat of Gloydius lipipengi sp. nov. (A Muza Village, Zaty, Tibet, type locality of G. lipipengi sp. nov. B the landscape of the Nujiang River, 15 km from the type locality) and Gloydius swild sp. nov. (C Heishui, Sichuan) A and B Photographs by Jin-Cheng Liu.