Achalinus nanshanensis H. Li, L.-Q. Zhu, Z.-Q. Zhang & X.-Y. Mo, 2024

Li, Hui, Zhu, Le-Qiang, Xiao, Bei, Huang, Jie, Wu, Shao-Wu, Yang, Li-Xun, Zhang, Zhi-Qiang & Mo, Xiao-Yang, 2024, A new species of the genus Achalinus (Squamata, Xenodermatidae) from southwest Hunan Province, China, ZooKeys 1189, pp. 257-273 : 257

publication ID

https://dx.doi.org/10.3897/zookeys.1189.112784

publication LSID

lsid:zoobank.org:pub:102C8154-87DF-4B55-8994-F625B8F3E46A

persistent identifier

https://treatment.plazi.org/id/353AD101-0B8D-4C85-88FE-0E0C63120051

taxon LSID

lsid:zoobank.org:act:353AD101-0B8D-4C85-88FE-0E0C63120051

treatment provided by

ZooKeys by Pensoft

scientific name

Achalinus nanshanensis H. Li, L.-Q. Zhu, Z.-Q. Zhang & X.-Y. Mo
status

sp. nov.

Achalinus nanshanensis H. Li, L.-Q. Zhu, Z.-Q. Zhang & X.-Y. Mo sp. nov.

Fig. 3 View Figure 3

Type materials.

Holotype: China • adult ♂; Hunan Province, Shaoyang City, Chengbu County, Nanshan National Park; 26°11′46.34″N, 110°07′56.38″E, alt. 1665 m; 1 Sept. 2023; Hui Li & Leqiang Zhu leg.; HNNU230903. Paratypes: China • 1 adult ♂; Hunan Province, Huaihua City, Tongdao County; 25°54′42.37″N, 109°44′31.39″E; alt. 300 m; 14 Oct. 2022; Shaowu Wu & Lixun Yang leg.; HNNU230901 • 1 adult ♂; same locality and date as holotype; HNNU230902.

Etymology.

The new species is named for on its type locality. We suggest the Chinese common name 南山脊蛇 (pin yin: Nán Shān Jǐ Shé) and the English common name Nanshan odd-scaled snake.

Diagnosis.

The new species can be distinguished from other members of Achalinus by the following characteristics: (1) dorsal scales with 23 or 25 rows throughout and strongly keeled; (2) tail relatively longer so that TaL/ToL = 0.215-0.248; (3) length of suture between internasals significantly longer than that between prefrontals, LSBI/LSBP = 1.66-1.84; (4) single loreal scale present; (5) SPL 6 in number, with the fourth and fifth contacting eye; (6) IFL 6 in number, with the first three touching the first pair of chin shields; (7) TMP is 2-2-4/2-2(3)-4, with the anterior pair elongated and in contact with the eye; (8) ventrals 2 + 147-158; (9) subcaudals 64-77, unpaired; (10) dorsal body brownish black with a bright-yellow neck collar extending to the head and abdomen in the occipital region.

Description of holotype.

Adult male with a total length of 461 mm (SVL 362 mm and TaL 99 mm), tail relatively long, TaL/ToL 0.215, body slender and cylindrical. Head distinct from neck, rostral small, triangular, only upper tip visible from above. Head length 10.95 mm, head width 7.25 mm. Length of suture between internasals much longer than that between prefrontals (LSBI 1.78 mm, LSBP 1.07 mm, LSBI/LSBP 1.66). Frontal pentagonal pointed backwards, much shorter than parietals; each parietal bordered with an elongated nuchal, with no preoculars and postoculars. Nostril at anterior part of nasal scale, posterior margin of nostril with a distinct nostril cleft. A single loreal scale present, extending from nasal scale to eye, distinctly wider than high. Eyes small, ED 1.11 mm. Two aTMP and four pTMP present; aTMPs elongated, upper one much smaller than the lower one; upper one in contact with eye, lower one also in contact with parietal scale. SPL 6 in number, the fourth and fifth in contact with the eye, the sixth longest. Two pairs of shields present, the first three in contact with first chin shield. One mental scale present, the first IFL in contact with each other after the mental scale, followed by another 5 IFL in contact with each other. Dorsal scales 23-23-23, strongly keeled; dorsum with no longitudinal vertebral stripe. VEN 155 in number. SC 64 in number, uniserial, anal entire.

Coloration of holotype in life.

Scales possess a subtle iridescent quality. The dorsum’s distinguishing characteristic is its reflective, brownish-black appearance, with a notable bright-yellow patch that extends to the head and abdomen in the occipital region. The first pair of chin shields displays black coloration at the front, while the second pair is entirely white. The eyes are uniformly black. The ventral side is prevalently grayish white, with the edges of the ventral scales gradually transitioning from grayish white to black. The ventral coloration of the tail mirrors that of the dorsum, featuring a brownish-black hue.

Coloration in preservative.

(Figs 4 View Figure 4 , 5 View Figure 5 ) All scales retain a subtle iridescence. The coloration darkens as it transitions from the dorsum to the venter, with the dorsal surface of the body primarily appearing brownish black. Notably, the collar of the neck is a paler grayish white.

Distribution and habits.

(Fig. 6 View Figure 6 ) Achalinus nanshanensis sp. nov. is currently known from Hunan Province, China, and specifically from Nashan National Park, Shaoyang City, and Tongdao County in Huaihua City. It has a known elevational range of 300-1665 m above sea level. All three specimens were found during the night, with the holotype and one paratype found near a mountain stream where the air temperature was 18 °C and the relative humidity was 80%. These individuals were close to shrubs in a subtropical broadleaved evergreen forest. They were found making their way from leaf litter to the stream. The other specimen was found in a bamboo forest near a steam.

Comparison.

A summary of morphological characteristics is listed in Table 4 View Table 4 . Phylogenetically, A. nanshanensis sp. nov. is closest to A. yangdatongi Hou, Wang, Guo, Chen, Yuan & Che, 2021 and A. damingensis Xu, Yang, Wu, Gong, Huang & Huang, 2023. However, A. nanshanensis sp. nov. differs from A. yangdatongi in having fewer ventral scales (147-158 vs 155-177), maxillary teeth (18 vs 24-26) and more temporals (2+2/3+4 vs 2+2/3+2/3), shorter loreal (0.47-0.53 vs 0.57) (Table 5 View Table 5 ). The new species differs from A. damingensis in having more temporals (2-2/3-4 vs 2-2-3) and fewer ventral scales (147-158 vs 165).

The new species differs from A. hunanensis Ma, Shi, Xiang, Shu & Jiang, 2023 in having fewer ventral scales (147-158 vs 163-165), maxillary teeth (18 vs 23), and a bright-yellow collar around the neck.

The new species differs from A. ningshanensis Yang, Huang, Jiang, Burbrink, Gong, Yu, Zhang, Huang & Huang, 2022 in having more infralabials (6 vs 5), two pairs of chin shields (vs 3 pairs), LSBI significantly longer than LSBP (vs suture between internasals is similar in length when compared to the suture between prefrontals).

The new species differs from A. ater in having more temporals (2+2/3+4 vs 2+2+3), fewer ventral scales (147-158 vs 160-170), more SC (64-77 vs 47-70) and a bright-yellow collar around the neck.

The new species differs from A. juliani Ziegler, Nguyen, Pham, Nguyen, Pham, van Schingen, Nguyen & Le, 2019 in having fewer ventral scales (147-158 vs 173-179), fewer subcaudals (64-77 vs 77-91), and a bright-yellow collar around the neck.

The new species differs from A. pingbianensis Li, Yu, Wu, Liao, Tang, Liu & Guo, 2020 in having a separated loreal (vs loreal fused with prefrontal), more subcaudals (64-77 vs 56), LSBI significantly longer than LSBP (vs length of suture between internasals subequal to that between prefrontals), two anterior temporals in contact with the eye (vs only the upper anterior temporal in contact with the eye), fewer supralabials (6 vs 7), and a bright-yellow collar around the neck.

The new species differs from A. timi Ziegler, Nguyen, Pham, Nguyen, Pham, Van Schingen, Nguyen & Le, 2019 in having one loreal (vs no loreals), more infralabials (6 vs 5), temporals (2+2/3+4 vs 2+2+3), fewer ventral scales (147-158 vs 170), and fewer tooth (18 vs 27).

The new species differs from A. vanhoensis Ha, Ziegler, Sy, Le, Nguyen & Luu, 2022 in having fewer ventral scales (147-158 vs 176), fewer subcaudals (64-77 vs 84) and more temporals (2+2/3+4 vs 2+3+3).

The new species differs from A. dabieshanensis Zhang, Liu, Huang & Zhang, 2023, A. huangjietangi Huang, Peng & Huang, 2021, A. niger Maki, 1931 and A. spinalis Peters, 1869 by LSBI significantly longer than LSBP (vs suture between internasals). Furthermore, the new species differs from A. dabieshanensis in having more infralabials (6 vs 5). It differs from A. huangjietangi and A. spinalis in having more subcaudals in males (64-77 vs 59-67 and 64-77 vs 48-67, respectively). It differs from A. niger in having comparatively longer tail (0.215-0.248 vs 0.151-0.179).

The new species differs from A. formosanus Boulenger, 1908, A. jinggangensis Zong & Ma, 1983 and A. zugorum Miller, Davis, Luong, Do, Pham, Ziegler, Lee, De Queiroz, Reynolds & Nguyen, 2020 in having a separated loreal (vs no loreal). Furthermore, the new species differs from A. formosanus in having fewer dorsal scale rows (23-25)-(23-25)-(23-25) vs (29)27-27-25). It differs from A. jinggangensis in having more subcaudals (64-77 vs 51-64) and from A. zugorum in having fewer infralabials (6 vs7) and more temporals (2+2/3+4 vs 2+2+3).

The new species differs from A. meiguensis Hu & Zhao, 1966 in having more dorsal scale rows (23-23-23 vs (21-23)-(19-21)-(19-21), more subcaudals (64-77 vs 50-60), and having two pairs of chin shields (vs three pairs of chin shields).

The new species differs from A. panzhihuaensis Hou, Wang, Guo, Chen, Yuan & Che, 2021 in having more temporals (2+2/3+4 vs 2+3+3) and fewer ventral scales (147-158 vs 160).

The new species differs from A. dehuaensis Li, Wu, Xu, Zhu, Ren, Guo & Dong, 2021 in having more infralabials (6 vs 5) and fewer maxillary teeth (18 vs 31-33), and a bright-yellow collar around the neck.

The new species differs from A. emilyae Ziegler, Nguyen, Pham, Nguyen, Pham, van Schingen, Nguyen & Le, 2019 in having more infralabials (6 vs 5), temporals (2+2/3+4 vs 2+2+3), and a bright-yellow collar around the neck, and the new species differs from A. emilyae in the color of its dorsum (brownish-black vs pale yellowish brown).

The new species differs from A. hainanus Huang, 1975 in having more infralabials (6 vs 5), temporals (2+2/3+4 vs 1+2+3(4) and LSBI significantly longer than LSBP (vs suture between internasals similar size when compared to the suture between prefrontals).

The new species differs from A. rufescens Boulenger, 1888 in having more infralabials (6 vs 5) and two pairs of chin shields (vs three pairs of chin shields).

The new species differs from A. tranganensis Luu, Ziegler, Ha, Lo, Hoang, Ngo, Le, Tran & Nguyen, 2020 in having more temporals (2+2/3+4 vs 2+2+3) and fewer ventral scales (147-158 vs 171).

The new species differs from A. werneri Van Denburgh, 1912 in having a shorter tail (0.215-0.248 vs 0.250-0.300), fewer ventrals (147-158 vs 157-191) and LSBI significantly longer than LSBP (vs suture between internasals similar size when compared to the suture between prefrontals).

The new species differs from A. yunkaiensis Wang, Li & Wang, 2019 in having a comparatively longer tail in males (0.215-0.248 vs 0.185-0.203), more subcaudals (64-77 vs 49-56) and LSBI significantly longer than LSBP (vs suture between internasals similar size when compared to the suture between prefrontals).

Kingdom

Animalia

Phylum

Chordata

Class

Reptilia

Order

Squamata

Family

Xenodermatidae

Genus

Achalinus