Gloydius lateralis Zhang, Shi, Jiang & Shi, 2022

Zhang, Mei-Hua, Shi, Sheng-Chao, Li, Cheng, Yan, Peng, Wang, Ping, Ding, Li, Du, Jie, Plenkovic-Moraj, Anđelka, Jiang, Jian-Ping & Shi, Jing-Song, 2022, Exploring cryptic biodiversity in a world heritage site: a new pitviper (Squamata, Viperidae, Crotalinae) from Jiuzhaigou, Aba, Sichuan, China, ZooKeys 1114, pp. 59-76 : 59

Gloydius lateralis Zhang, Shi, Jiang & Shi sp. nov.

Figs 2 , 3 , 4 , 5 , 6

Chresonymy.

Gloydius strauchi - Li et al. 2004

Holotype.

CIB 119377 (collection number: JZ02, Figs 2 - 3 ), аdult female, collected from Zharu Valley, Jiuzhaigou National Nature Reserve, Aba Tibetan and Qiang Autonomous Prefecture, Sichuan Province, China (33.26°N, 103.93°E, 2072 m a.s.l.), leg. Chun-Lin Zhao, Peng Yan, and Tao Yang, 8 Jun. 2021.

Paratypes.

Three adult females: IVPP OV 2727, CIB 119378, and CIB 119379 (JZ01, JZ03, and JZ04; Fig. 4 ), leg. Peng Yan and Mei-Hua Zhang 31 Aug. 2021. Four adult females (SAFS2021001-SAFS2021004), leg. Ping Wang, Jun. 2021; one adult male (CIB 87280), leg. Cheng Li, 23 May 2002. All paratypes were collected from the same locality of the holotype.

Diagnoses.

The above-mentioned specimens were identified as members of the genus Gloydius based on the small body size, bilateral pits, and divided subcaudal scales ( Zhao 2006; Shi et al. 2016, 2017, 2018, 2021). G. lateralis sp. nov. differs from other congeneric species by a combination of the following characteristics: (1) relatively larger eyes (ED/HL: 0.145-0.171, n = 5); (2) three palatine teeth; (3) 20 or 21 rows of mid-body dorsal scales; (4) ventrals 151-163 (n = 9); (5) subcaudals 38-49 (n = 6); (6) dorsal body laurel green or light brown with four rows of zigzag, dark brown patches, the medial two rows separated from each other by alternate phyllotaxis pattern in background color; (7) continuous, regular greyish-brown ventrolateral stripe on each side of body and tail.

Comparisons.

Compared to other species in the genus Gloydius , G. lateralis sp. nov. has continuous, regular greyish-brown and pale, greyish-white ventrolateral stripes on both sides (vs disconnected white upper bordered ventrolateral stripes in G. qinlingensis and G. liupanensis ; lacking the ventrolateral stripes in other congeneric species), and relatively larger eyes than the congeneric species (the ratio between the eye diameter and head length ranges from 0.145-0.171 in G. lateralis sp. nov. vs <0.134 in others).

Gloydius lateralis sp. nov. can be differentiated from the species in the G. blomhoffii group by having three palatine teeth (vs four), from the G. halys complex by having 20 or 21 rows of mid-body dorsal scales (vs 22 or 23).

For species in the G. strauchi group, Gloydius lateralis sp. nov. can be differentiated from G. monticola by having 20 or 21 rows of mid-body dorsal scales (vs 19 in G. monticola ). Given the similar to G. angusticeps , G. lateralis sp. nov. can be differentiated from the latter by the larger eyes (ED/HL 0.145-0.171 vs 0.104-0.119) and the ticker postorbital stripes. Additionally, the ventrolateral stripes sometimes appear in some other Gloydius species, such as G. qinlingensis and G. liupanensis , but G. lateralis sp. nov. differs from them by having the ventrolateral stripe lacking a white upper edge. Gloydius lateralis sp. nov. differs from G. strauchi , G. rubromaculatus , G. lipipengi , and G. huangi by the triangular head in dorsal view (vs spoon-shaped head: Figs 5 , 6 ).

Gloydius swild is another species from Heishui, Aba, Sichuan (female holotype IVPP OV 2725 and paratype IVPP OV 2726) that is phylogenetically most closely related to G. lateralis sp. nov., but G. swild can be separated from the latter by significant branch lengths and p -distance (6.1%). G. lateralis sp. nov. differs from G. swild by having fewer ventrals 151-163 (n = 9) (vs 168-170, n = 2), laurel-green dorsal body with deep-colored patches (vs dark, greyish-brown background dorsal color), relatively larger eyes (ED/HL 14.5-17.1%, n = 5 vs 11.5-13.4%, n = 2), the thicker postorbital stripes (2/3 the width of the anterior temporal vs half the width of the anterior temporal), and the regular greyish-brown ventrolateral stripes (vs irregular ventrolateral stripes).

Description of the holotype.

CIB 119377 (JZ02), adult female, body slender, medium-sized, tail short (SVL 440.0 mm, TL 58.0 mm, TL/TTL 0.116). Head triangular in dorsal view, 1.45 × the length of the width, distinct from the neck (HW 15.1 mm, HL 21.9 mm, HH 8.3 mm); snout bluntly protruding (SL 6.4 mm) from dorsal view; upper jaw slightly protruding beyond lower jaw; rostral scales barely seem from dorsal view; canthus rostralis blunt; eyes relatively large (ED 3.2 mm), pupil vertical, ED/HL 0. 146. Pupil vertical. Fang not exceeding third infralabial (Fig. 2 ).

Scalation . Internals wider than long, near right triangular (IN 4.4 mm); prefrontals larger, pentagonal; frontal shield-like; the curve edges of two parietals contacting 13 small scales posterior to frontal and supraoculars; supraocular large, slightly smaller than frontal (IOS 7.8 mm); remaining dorsal head scales smaller posteriorly, first few rows irregular and smooth, gradually rhomboidal and keeled posteriorly. Nasals partially divided into two parts by two disconnected vertical sutures touching rear edge of nostril; two loreals, upper loreal forms part of canthus rostralis, lower loreals distinctly smaller and join pit; preoculars 3/2 (left/right), upmost forms part of canthus rostralis, lower join the pit; postoculars 2/2, upper pair small, lower pair larger, and crescent-shaped, surrounding about one-third of eye, touching third supralabial; temporals 2+3/2+2. Supralabials 6/6: first supralabial in contact with both parts of nasals; second supralabial smallest, fourth and fifth supralabials longest; third supralabial reaching the bottom of orbit; fourth supralabial slightly larger than the following. Infralabials 10/10; first pair extends behind mental, first four pairs narrow and touching chin shields, fifth and sixth infralabials largest, similar in size; one pair of chin shields enlarged, forming a distinct mental groove. Dorsal body scales rhombic with matte surface, keeled except the rows bordering ventrals, increasing in size from medial to lateral; dorsal scales rows 20-20-15; ventral scales 158; anal undivided; subcaudal scales 45 pairs (Fig. 3 ).

Coloration in life (Figs 2 , 4 - 6 ). Description based on observation immediately after shedding. Dorsal head gray with distinct smoky-black markings resembling a human in half squat; one gray patch present on middle of frontal; one gray U-shaped marking present on parietals. Lateral head light gray; postorbital stripe otter brown, wider than half of the largest anterior temporal, extending to lateral neck, without white margins; supralabials and infralabials light gray without conspicuous spots; iris bicolored, upper one-third gold, lower part marbled with smoky black; edges of pupil gold. Ventral head white; one faint yellow-orange stripe present on inner edges of infralabials and adjacent edges of contacting scales on both lateral sides of the lower lip. Tone uniformly purple-taupe.

Dorsal body laurel green; two rows of pine-needle colored irregular patches present on dorsolateral body behind head markings, each patch involving several scales (mostly 4-8) on seventh to higher dorsal scale rows, and partially connected or separated by one laurel-green scale; vertebral scales mostly laurel green, forming an alternate phyllotaxis pattern on the body after neck; a row of copper patches present on both sides of lateral body behind postorbital stripe, involving several scales (5-7) on dorsal scale rows 3-6, also partially connected or separated by one laurel-green scale. Ventral body white right behind head, mottled with sparse smoky-black spots, gradually dense to posterior; a distinct, continuous, regular, greyish-brown ventrolateral stripe present on each side of body, behind faint yellow-orange stripe, lie on junction of ventrals and lower edge of first dorsal scales. Dorsal tail smoky black, covered with a dozen of small, laurel-green patches or transverse bands. Ventral tail laurel green with dense, smoky-black spots, continuous, regular, greyish brown, extending from body to middle of ventrolateral tail. Skin between all dorsal scales black. Front edge of most dorsal scales dyed black.

Variations.

Measurements and body scalation variations are listed in Table 1. One of the paratypes, CIB 119378 (JZ03) has a more deeply brown background color than other specimens, dorsal scales on body ginger, and lateral patches on body chestnut; ventrolateral stripes saddle brown. A small, dark-brown spot presents on the middle of the posterior head of one of the paratypes CIB 119378 (JZ03), IVPP OV 2727 (JZ01). Postoculars 3/3 in CIB 87280, IVPP OV 2727 (JZ01); 2/3 in CIB 119379 (JZ04).

Etymology.

The specific epithet Gloydius lateralis refers to the unique continuous, regular, greyish-brown ventrolateral stripes at the junction of ventrals and the first row of dorsal scales. The common name is suggested as "Jiuzhai pitviper" in English, "Jiǔ Zhài Fù” (九寨蝮) in Chinese, refer to its type locality, JNNR.

Distribution and ecology.

At present, G. lateralis sp. nov. is only known from JNNR, Sichuan, China. The type specimens were collected from the middle of June to the end of August. Gloydius lateralis sp. nov. is active on sunny days by the roadside in a hot, dry valley (Fig. 8 ). This species is sympatric with Protobothrops jerdonii , Rhabdophis nuchalis , and Scincella tsinlingensis . The food spectrum of the new species includes small mammals based on a small patch of fur observed in feces. They fed on suckling mice in captivity.

Figures

Figure 2. Holotype of Gloydius lateralis sp. nov. in life, adult female, CIB 119377 (JZ 02) A dorsolateral view B ventral view.

Figure 3. Head squamation of holotype of Gloydius lateralis sp. nov. CIB 119377 (JZ 02) A lateral view B ventral view C dorsal view. Scale bar: 10 mm.

Figure 4. Paratypes of Gloydius lateralis sp. nov. in life A, B CIB 119379 (JZ 04), adult female in dorsolateral and ventral views C, D CIB 119378 (JZ 03), adult female in dorsolateral and ventral views.

Figure 5. Lateral (dorsolateral) heads of the alpine pitvipers (Gloydius) distributed in Sichuan and Tibet (not to scales) A G. lateralis sp. nov., CIB 119377 (JZ 02), female, from Jiuzhaigou National Nature Reserve, Sichuan B G. swild, IVPP OV 2725, female, from Heishui, Sichuan C G. angusticeps, IVPP OV 2634, male, from Zoige, Sichuan D G. liupanensis, male, from Longnan, Gansu E G. qinlingensis, male, from Ningshaan, Shaanxi F G. strauchi, SYNU 1508 G 4, male, from Litang, Sichuan G G. lipipengi, IVPP OV 2720, male, from Zayu, Tibet H G. rubromaculatus, male, from Yushu, Qinghai (not included in this study) I G. huangi, CIB 533422012, male, from Hola, Mangkang. Copyright: Sheng-Chao Shi (A, I), Jing-Song Shi (B, C, E, F, G, H), Zu-Yao Xia (D).

Figure 6. Lateral (dorsolateral) view of the alpine pitvipers (Gloydius strauchi complex) that distributed in Sichuan and Tibet (not to scales); the lateral stripes are pointed by arrows A G. lateralis sp. nov., CIB 119377 (JZ 02), female, from Jiuzhaigou, Sichuan B G. swild, IVPP OV 2725, female, from Heishui, Sichuan C G. angusticeps, male, from Golog, Qinghai (not included in this study) D G. liupanensis, male, from Longnan, Gansu E G. qinlingensis, male, from Ningshaan, Shaanxi F G. strauchi, from Sichuan G G. lipipengi, IVPP OV 2720, male, from Zayu, Tibet H G. rubromaculatus, male from Yushu, Qinghai I G. huangi, CIB 533422012, male, from Hola, Mangkang. Copyright: Sheng-Chao Shi (A, I), Jing-Song Shi (B, E, G, H), Hong Zhao (C), Zu-Yao Xia (D) and Zhi-Yuan Tang (F).

Figure 8. A, C Macrohabitats and D microhabitats of Gloydius lateralis sp. nov. at the Jiuzhaigou National Nature Reserve. Note that another Protobothrops jerdonii sympatric to G. lateralis sp. nov. is shown in B.