Research Article |
Corresponding author: Zhi-Qiang Zhang ( csfuzzq@126.com ) Corresponding author: Xiao-Yang Mo ( moxiaoyang@hunnu.edu.cn ) Academic editor: Robert Jadin
© 2024 Hui Li, Le-Qiang Zhu, Bei Xiao, Jie Huang, Shao-Wu Wu, Li-Xun Yang, Zhi-Qiang Zhang, Xiao-Yang Mo.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Li H, Zhu L-Q, Xiao B, Huang J, Wu S-W, Yang L-X, Zhang Z-Q, Mo X-Y (2024) A new species of the genus Achalinus (Squamata, Xenodermatidae) from southwest Hunan Province, China. ZooKeys 1189: 257-273. https://doi.org/10.3897/zookeys.1189.112784
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A new species of xenodermid snake, Achalinus nanshanensis H. Li, L.-Q. Zhu, Z.-Q. Zhang & X.-Y. Mo, sp. nov., is described based on three specimens collected from Nanshan National Park and Tongdao County of southwest Hunan Province. This new species is genetically distinct amongst its congeners with the mitochondrial COI uncorrected p-distance ranging from 4.4% (in A. yangdatongi) to 17.7% (in A. meiguensis). In addition, this new species can be distinguished from its congeners by a combination of the following morphological characters: (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. The recognition of the new species increases the number of described Achalinus species to 28, of which 21 are found in China.
Achalinus nanshanensis sp. nov., molecular analyses, morphology, taxonomy
Xenodermidae is composed of six known genera (Xenodermus Reinhardt, 1836, Achalinus Peters, 1869, Stoliczkia Jerdon, 1870, Fimbrios Smith, 1921, Parafimbrios Teynié, David, Lottier, Le, Vidal & Nguyen, 2015, and Paraxenodermus Deepak, Lalronunga, Lalhmingliani, Das, Narayanan, Das & Gower, 2021). The genus Achalinus is the most diverse genus of the family Xenodermidae (
During recent herpetological surveys in southwest Hunan, China, three Achalinus snake specimens were collected in Tongdao County and Nanshan National Park. The specimens exhibit the morphological characteristics of the genus Achalinus, which include a small, elongated, cylindrical body; strongly keeled, lanceolate scales with a metallic luster; and the lack of preocular and postocular scales, featuring a single loreal scale and temporals that are in direct contact with the eyes (Peters, 1869;
Three odd-scaled snake specimens were collected in Hunan Province, China: two specimens (HNNU230902, HNNU230903) were collected in Nanshan National Park, and one specimen (HNNU230901) was collected in Tongdao County (Fig.
Localities, voucher information, COI GenBank accession numbers, and references for all samples used in this study.
No. | Species | Voucher | Locality | GenBank | References |
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1 | A. nanshanensis sp. nov. | HNNU230901 | Tongao, Huaihua, Hunan, China | OR523368 | This study |
2 | A. nanshanensis sp. nov. | HNNU230902 | Nanshan National Park, Hunan, China | OR523369 | This study |
3 | A. nanshanensis sp. nov. | HNNU230903 | Nanshan National Park, Hunan, China | OR523370 | This study |
4 | A. ater | SYSr00852 | Huaping Nature Reserve, Guangxi, China | MN380334 |
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5 | A. dabieshanensis | AHU2018EE0710 | Fuziling Provincial Reserve, Anhui, China | MW316598 |
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6 | A. damingensis | ANU20220009 | Shanglin, Nanning, Guangxi, China | OP644487 | Ynang et al. 2023 |
7 | A. dehuaensis | YBU13013 | Dehua, Fujian, China | MZ442642 |
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8 | A. emilyae | IEBR4465 | HoanhBo, Quang Ninh, Vietnam | MK330857 |
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9 | A. formosanus | RN2002 | Taiwan, China | KU529452 | Unpublished |
10 | A. huangjietangi | HSR18030 | Huangshan, Anhui, China | MT380191 |
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11 | A. hunanensis | CIB119039 | Huaihua, Hunan, China | OQ848425 | Ma et al. 2023 |
12 | A. hunanensis | CIB119040 | Ningxiang, Hunan, China | OQ848426 | Ma et al. 2023 |
13 | A. juliani | IEBRA.2018.8 | HaLang, Cao Bang, Vietnam | MK330854 |
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14 | A. meiguensis | GP835 | Mianyang, Sichuan, China | MZ442641 |
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15 | A. niger | RN0667 | Taiwan, China | KU529433 | Unpublished |
16 | A. ningshanensis | ANU20220006 | Ningshan, Shaanxi, China | ON548422 |
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17 | A. ningshanensis | ANU20220007 | Ningshan, Shaanxi, China | ON548423 |
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18 | A. panzhihuaensis | KIZ040189 | Yanbian, Sichuan, China | MW664862 |
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19 | A. pingbianensis | YBU18273 | Honghe, Yunnan, China | MT365521 |
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20 | A. quangi | sp4 | northern Vietnam | OQ197471 | Anh et al. 2023 |
21 | A. rufescens | SYSr001866 | Hongkong, China | MN380339 |
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22 | A. spinalis | SYSr001327 | Badagong Mountains, Hunan, China | MN380340 |
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23 | A. timi | IEBRA.2018.10 | ThuanChau, Son La, Vietnam | MK330856 |
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24 | A. tranganensis | VNUFR.2018.21 | NinhBinh, Vietnam | MW023086 |
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25 | A. vanhoensis | VNUFR.2019.13 | VanHo, Son La, Vietnam | ON677935 |
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26 | A. yangdatongi | KIZ034327 | Wenshan Nature Reserve, Yunnan, China | MW664865 |
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27 | A. yangdatongi | YPX51447 | Xichou county, Yunnan, China | MW664864 |
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28 | A. yangdatongi | YPX51446 | Xichou county, Yunnan, China | MW664863 |
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29 | A. yunkaiensis | SYSr001443 | Dawuling Forestry Station, Guangdong, China | MN380329 |
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30 | A. zugorum | IEBR4698 | Bac Me, Ha Giang, Vietnam | MT502775 |
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31 | Fimbrios klossi | IEBR3275 | Quang Ngai, Vietnam | KP410744 | Teynié et al. 2015 |
32 | Parafimbrios lao | MNHN2013.1002 | Louangphabang, Laos | KP410746 | Teynié et al. 2015 |
33 | Xenodermus javanicus | – | Sumatera Barat, Indonesia | KP410747 | Teynié et al. 2015 |
Distribution of some species of the genus Achalinus, Red star: the type locality of A. nanshanensis sp. nov. (HNNU230902, HNNU230903): Nanshan Nation Park, Shaoyang City, Hunan Province, China; A. nanshanensis sp. nov. (HNNU230901): Tongdao County, Huaihua City, Hunan Province, China. Blue triangle: the type locality of A. yangdatongi in Xichou County, Yunnan Province; Black circle: the type locality of A. damingensis in Shanglin County, Guangxi Province. Purple diamond: the type locality of A. hunanensis in Hecheng District and Ningxiang County, Hunan Province.
Morphological descriptions follow
The scale features and their abbreviations are as follows:
,loreals (Lor);
,supralabials (SPL);
,infralabials (IFL);
,number of chin shield pairs (Chins); infralabials touching the first pair of chin shields (IFL-1st Chin);
,postoculars (PtO);
,temporals (TMP);
,supraoculars (SPO);
,temporals (TEM),
,number of anterior temporals that touch the eye (aTEM-Eye) (head bilateral scale counts are given as left/right),
,pre-ventral scales (PrV),
,ventral scales (VEN),
,subcaudal (SC),
,entire or divided state of the anal scales (Anal),
,dorsal scale rows (DSR) (counted at one-head-length behind the head, at midbody, and at one-head-length before the anal);
,the number of maxillary teeth (MT). We also make comparisons with other species of the genus Achalinus based on available literature (
Genomic DNA was extracted from preserved liver tissue using the TIANamp Genomic DNA Kit. The fragment of the mitochondrial DNA gene encoding cytochrome c oxidase subunit I (COI) was amplified using the primer pairs Chfm4 and Chrm4 (
The COI sequences (629 bp) were assembled using SeqMan in the DNASTAR software package (
The maximum-likelihood (ML) and Bayesian-inference (BI) analyses resulted in essentially identical topologies, which are integrated in Fig.
Uncorrected p-distances (%) among Achalinus species inferred from mitochndrial COI gene.
1–3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11–12 | 13 | 14 | 15 | 16–17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26–28 | 29 | |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1–3 A. nanshanensis sp. nov. | 0–0.5 | ||||||||||||||||||||||
4 A. ater | 6.7–6.9 | ||||||||||||||||||||||
5 A. dabieshanensis | 16.0 | 14.7 | |||||||||||||||||||||
6 A. damingensis | 5.3–5.8 | 8.2 | 15.8 | ||||||||||||||||||||
7 A. dehuaensis | 14.3–14.6 | 16.5 | 18.4 | 16.0 | |||||||||||||||||||
8 A. emilyae | 12.8–13.0 | 11.7 | 17.7 | 13.0 | 15.5 | ||||||||||||||||||
9 A. formosanus | 14.4–14.9 | 14.1 | 19.0 | 14.9 | 15.9 | 13.9 | |||||||||||||||||
10 A. huangjietangi | 16.6 | 15.0 | 8.9 | 16.3 | 16.5 | 14.5 | 15.6 | ||||||||||||||||
11–12 A. hunanensis | 4.7–5.6 | 7.1–7.3 | 16.9–17.1 | 6.1–6.3 | 14.9–15.3 | 13.0–13.2 | 13.7–14.0 | 16.8 | 0.5 | ||||||||||||||
13 A. juliani | 7.7–7.9 | 7.1 | 15.8 | 8.5 | 14.9 | 12.3 | 12.5 | 14.6 | 8.7–8.8 | ||||||||||||||
14 A. meiguensis | 17.7 | 15.4 | 17.7 | 16.8 | 18.1 | 15.4 | 15.6 | 15.2 | 16.4 | 16.8 | |||||||||||||
15 A. niger | 12.8–13.3 | 13.5 | 15.8 | 14.3 | 15.9 | 12.2 | 9.1 | 13.9 | 13.2–13.3 | 12.3 | 13.9 | ||||||||||||
16–17 A. ningshanensis | 5.1–5.6 | 7.6–7.7 | 17.1–17.2 | 7.2–7.8 | 16.3–16.5 | 13.5–14.1 | 14.8–15.1 | 17.2 | 3.2–3.4 | 9.1–9.6 | 17.0 | 14.6 | 0.7 | ||||||||||
18 A. panzhihuaensis | 15.1–15.5 | 16.2 | 16.6 | 15.5 | 15.3 | 16.6 | 16.0 | 15.2 | 16.2 | 15.5 | 11.6 | 14.4 | 17.1–17.4 | ||||||||||
19 A. pingbianensis | 11.6–11.8 | 11.8 | 15.3 | 11.3 | 14.9 | 12.9 | 14.6 | 13.0 | 11.1 | 12.1 | 16.8 | 11.8 | 11.7–12.4 | 14.9 | |||||||||
20 A. quangi | 12.8–13.1 | 11.7 | 18.1 | 13.1 | 15.4 | 3.5 | 13.9 | 15.0 | 13.2 | 12.7 | 15.2 | 13.4 | 12.8–13.4 | 16.9 | 13.9 | ||||||||
21 A. rufescens | 11.9–12.0 | 12.7 | 16.9 | 13.8 | 14.3 | 8.0 | 14.1 | 14.3 | 12.1 | 12.3 | 17.3 | 12.3 | 12.3–12.7 | 16.0 | 12.9 | 7.9 | |||||||
22 A. spinalis | 13.9–14.1 | 15.2 | 16.6 | 15.1 | 14.3 | 13.9 | 13.9 | 13.4 | 13.9 | 13.9 | 16.0 | 15.6 | 15.1–15.6 | 15.8 | 13.3 | 13.9 | 13.0 | ||||||
23 A. timi | 13.6–13.8 | 13.3 | 16.4 | 13.5 | 16.0 | 13.1 | 13.8 | 14.8 | 12.0 | 14.1 | 15.8 | 13.6 | 13.6 | 15.5 | 12.3 | 13.6 | 13.9 | 14.3 | |||||
24 A. tranganensis | 13.0–13.1 | 12.7 | 15.3 | 13.9 | 13.9 | 11.5 | 16.8 | 13.4 | 14.0 | 13.3 | 16.4 | 15.2 | 14.3–15.2 | 16.4 | 13.3 | 12.2 | 11.5 | 14.6 | 13.8 | ||||
25 A. vanhoensis | 12.4–12.8 | 13.1 | 15.5 | 12.6 | 16.0 | 12.2 | 14.0 | 14.6 | 11.5 | 13.6 | 15.6 | 12.1 | 12.1–12.4 | 15.5 | 10.8 | 12.4 | 13.8 | 12.9 | 5.2 | 13.3 | |||
26–28 A. yangdatongi | 4.4 | 6.2 | 16.6 | 5.6 | 14.0 | 12.8 | 14.4 | 14.6 | 5.1 | 7.3 | 17.1 | 5.9 | 5.8–5.9 | 15.5 | 11.3 | 12.6 | 11.5 | 14.2 | 13.1 | 12.8 | 11.3 | ||
29 A. yunkaiensis | 12.5–12.8 | 12.8 | 14.9 | 12.5 | 14.7 | 13.1 | 12.3 | 12.5 | 12.0 | 12.5 | 15.8 | 13.7 | 13.0–13.7 | 15.7 | 11.6 | 13.6 | 13.3 | 12.0 | 14.1 | 13.5 | 13.6 | 12.0 | |
30 A. zugorum | 12.8–13.0 | 13.1 | 15.3 | 12.8 | 14.3 | 12.3 | 13.1 | 14.3 | 11.8 | 13.1 | 15.0 | 12.8 | 12.8 | 15.3 | 11.0 | 12.7 | 13.5 | 13.3 | 13.6 | 11.9 | 11.9 | 12.2 | 10.9 |
Phylogenetic tree of the genus Achalinus inferred from CO1 gene fragments (629 bp) by maximum-likelihood analysis. The numbers above the branches represent the supporting values: SH-like approximate likelihood ratio test and Bayesian posterior probabilities (the ones lower than 50 are displayed as “-”). Achalinus nanshanensis sp. nov. is highlighted in blue and A. yangdatongi in yellow.
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.
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.
Voucher | |||
---|---|---|---|
HNNU230903 | HNNU230901 | HNNU230902 | |
Holotype | Paratype | Paratype | |
Sex | Adult male | Adult male | Adult male |
SVL | 362 | 302 | 300 |
TaL | 99 | 99 | 99 |
TL | 461 | 401 | 399 |
TaL/TL | 0.215 | 0.247 | 0.248 |
HL | 10.95 | 10.07 | 10.18 |
HW | 7.25 | 5.96 | 6.37 |
ED | 1.11 | 1.10 | 1.09 |
SPL | 6/6 | 6/6 | 6/6 |
SPL-Eye | 4th–5th | 4th–5th | 4th–5th |
IFL | 6 | 6 | 6 |
Chin | 2 | 2 | 2 |
IFL-1stChin | 1st–3rd | 1st–3rd | 1st–3rd |
SPO | 1 | 1 | 1 |
LorH | 0.83 | 0.77 | 0.72 |
LorL | 1.86 | 1.45 | 1.46 |
LorH / LorL | 0.47 | 0.53 | 0.49 |
LSBI | 1.78 | 1.52 | 1.49 |
LSBP | 1.07 | 0.86 | 0.81 |
LSBI / LSBP | 1.66 | 1.76 | 1.84 |
TEM | 2+2+4 | 2+2+4 | 2+2(rarely 3)+4 |
aTEM-Eye | 2 | 2 | 2 |
DSR | 23-23-23 | 23-23-23 | 25-25-25 |
VEN | 155 | 158 | 147 |
SC | 64 | 77 | 72 |
Anal | 1 | 1 | 1 |
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.
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.
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.
(Figs
(Fig.
A summary of morphological characteristics is listed in Table
A morphological comparison of male species of the genus Achalinus. Morphological data of examined congeners were taken from the literature. “–” & “?” = unavailable, “*” = female species (sevral species of genus Achalinus recorded only female samples).
Species | TaL/ToL | MT | LorH/LorL | LSBI vs. LSBP | DSR | Lor | PtO | SPL | SPL-Eye | IFL | IFL-1st Chin | TEM | aTEM-Eye | VEN | SC |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
nanshanensis sp. nov. | 0.215–0.248 | 18 | 0.47–0.53 | >1 | (23–25)-(23–25)-(23–25) | 1 | 0 | 6 | 4–5 | 6 | 1–3 | 2+2+4/2+2(3)+4 | 2 | 147–158 | 64–77 |
A. ater | 0.190 ~ 0.220 | – | 0.40 | > 1 | (21–23)-(21–25)-(21–25) | 1 | 0 | 6 | 4–5 | 5–6 | 1–3 | 2+2+3 | 2 | 146–164 | 50–66 |
A. dabieshanensis | 0.177 ~ 0.223 | – | 0.73 ~ 0.81 | < 1 | 23-23-23 | 1 | 0 | 6 | 4–5 | 5 | 1–3 | 2+2+4 | 2 | 141–151 | 46–55 |
damingensis | 427 | – | – | >1 | 23-23-23 | 1 | 0 | 6 | 4–5 | 6 | 1–3 | 2+2+3 | 2 | 165 | 74 |
A. dehuaensis | 0.262 ~ 0.286 | 31–33 | – | > 1 | 23-23-23 | 1 | 0 | 6 | 4–5 | 5 | 1–3 | 2+2(3)+3(4) | 1–2 | 142–143 | 74–81 |
A. emilyae* | 0.183 ~ 0.203 | 27–28 | – | > 1 | 23-23-23 | 1 | 0 | 6 | 4–5 | 5 | 1–3 | 2+2+3 | 1 | 157–161 | 56–63 |
A. formosanus | 0.159 | 17 | – | = 1 | 29(27)-27-25 | 0 | 0 | 6 | 4–5 | 6–7 | – | 2+2 | 1 | 158–184 | 61–83 |
A. hainanus* | 0.258 ~ 0.266 | – | – | = 1 | 23-23-23 | 1 | 0 | 6 | 4–5 | 5 | 1–3 | 1+2+3(4) | 1 | 165–168 | 67–69 |
A. huangjietangi | 0.211 ~ 0.232 | – | 0.70 ~ 0.74 | < 1 | 23-23-23 | 1 | 0 | 6 | 4–5 | 5–6 | 1–3(4) | 2+2+3(4) | 2 | 157–160 | 59–67 |
A. hunanensis | 0.221 ~ 0.225 | 23 | 0.62 ~ 0.70 | > 1 | 23-23-23 | 1 | 0 | 6 | 4–5 | 5–6 | 1–3(4) | 2+2+4 | 2 | 163–165 | 69–72 |
A. jinggangensis | 0.174 ~ 0.217 | – | – | > 1 | 23-23-23 | 0 | 0 | 6 | 4–5 | 6 | 1–4 | 2(1)+2+3(4) | 2 | 156–164 | 51–64 |
A. juliani | 0.264 ~ 0.265 | 28 | – | > 1 | 25-23-23 | 1 | 0 | 6 | 4–5 | 6 | 1–3(4) | 2+2+4 | 2 | 163–169 | 81–91 |
A. meiguensis | 0.142 ~ 0.238 | 17 | – | – | (21–23)-(19–21)-(19–21) | 1 | 1 | 6 | 4–5 | 6 | 1–3 | 2(3)+2(3) | 1 | 146–173 | 39–60 |
A. niger | 0.151 ~ 0.179 | – | 0.67 | < 1 | 25-25-23 | 1 | 0 | 6 | 4–5 | 6 | 1–3(4) | 2+2(3) | 2 | 169–185 | 52–72 |
A. ningshanensis* | 0.121 ~ 0.161 | – | 0.45 ~ 0.58 | = 1 | 23-23-23(21) | 1 | 0 | 6 | 4–5 | 5 | 1–2(3) | 2+2(3)+3(4) | 1–2 | 159–174 | 41–46 |
A. panzhihuaensis | 0.246 | 28 | 0.67 | – | 23-23-19 | 1 | 1 | 6 | 4–5 | 6 | 1–3 | 2+2+3 | 1 | 160 | 73 |
A. pingbianensis | 0.243 | – | – | = 1 | 23-23-23 | 0 | 0 | 7 | 5–6 | 6 | 1–3 | 2+2+3 | 1 | 164 | 56 |
A. rufescens | 0.191 ~ 0.221 | 23 | 0.90 | > 1 | 23-(23–25)-23 | 1 | 0 | 6 | 4–5 | 5 | 1–3 | 2(1)+2+3(4) | 1–2 | 148–156 | 58–69 |
A. spinalis | 0.150 ~ 0.250 | 16–20 | – | < 1 | (23–25)-(23–25)-(23–25) | 1 | 0 | 6 | 4–5 | 5–6 | 1–3 | 2+2(3) | 1–2 | 138–175 | 48–67 |
A. timi | 0.213 | 27 | – | > 1 | 25-25-23 | 0 | 0 | 6 | 4–5 | 6 | 1–3 | 2+2+3 | 1 | 170 | 72 |
A. tranganensis | 0.254(+) | 29 | – | > 1 | 25-23-23 | 1 | 0 | 6 | 4–5 | 6 | 1–3 | 2+2+3 | 2 | 171 | 73(+) |
A. vanhoensis | 0.264 | 32 | – | > 1 | 25-23-23 | 0 | 0 | 6/7 | 4–5/5–6 | 6 | 1–4 | 2+3+3 | 2 | 176 | 84 |
A. werneri | 0.250 ~ 0.300 | – | – | = 1 | ?-(21–23)-? | 1 | 0 | 6 | 4–5 | 6 | – | 2+3(4) | – | 157–191 | 67–98 |
A. yangdatongi | 0.261 ~ 0.262 | 26 | 0.57 | > 1 | 23-23-23 | 1 | 0 | 6 | 4–5 | 5–6 | 1–3 | 2+2+2/3 | 2 | 155-161 | 76-82 |
A. yunkaiensis | 0.185 ~ 0.203 | 20–24 | 0.49 ~ 0.64 | = 1 | 23-23-23 | 1 | 0 | 6 | 4–5 | 6 | 1–3(4) | 2+2+3(4) | 2 | 150–162 | 49–56 |
A. zugorum | 0.229 | 28 | – | > 1 | 25-23-23 | 0 | 0 | 6 | 4–5 | 7 | 1–3 | 2+2+3 | 2 | 173 | 70 |
Comparisons of main morphological characters of Achalinus nanshanensis sp. nov., A. yangdatongi, and Achalinus damingensis.
A. nanshanensis sp. nov. | A. yangdatongi | A. damingensis | ||
---|---|---|---|---|
Sex | Males | Males | Females | Males |
SVL | 300–392 | 241–293 | 292–424 | 322 |
TaL | 99 | 85–104 | 73–93 | 105 |
TL | 399–461 | – | – | 427 |
TaL/TL | 0.215–0.248 | 0.261–0.262 | 0.180–0.200 | 0.25 |
HL | 10.07–10.95 | 8.5–11.60 | 9.52–11.45 | – |
HW | 5.96–7.25 | – | – | – |
MT | 18 | 26 | 24 | – |
ED | 1.09–1.11 | – | – | – |
SPL | 6/6 | 6/6 | 6/6(rarely 5/5) | 6/6 |
SPL-Eye | 4th–5th | 4th–5th | 4th–5th | 4th–5th |
IFL | 6 | 5/6 | 6 | 6/6 |
Chin | 2 | 2 | 2 | 2 |
IFL-1stChin | 1st–3rd | 1st–3rd | 1st–3rd | 1st–3rd |
SPO | 1 | 1 | 1 | 1 |
LorH / LorL | 0.47–0.53 | 0.57 | 0.49 | – |
LSBI vs LSBP | >1 | >1 | >1 | >1 |
TEM | 2+2(rarely 3)+4 | 2+2+2/3 | 2+2/3+2/3 | 2+2+3 |
aTEM-Eye | 2 | 2 | 2 | 2 |
DSR | 23(25)-23(25)-23(25) | 23-23-23 | 23-23-23 | 23-23-23 |
VEN | 147–158 | 155 | 170–171 | 165 |
SC | 64–77 | 76 | 59–64 | 74 |
Anal | 1 | 1 | 1 | 1 |
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).
With the discovery of Achalinus nanshanensis sp. nov., the number of Achalinus species now stands at 28, with 21 occurring in China: A. ater (Bourret, 1937), A. dabieshanensis (
Recent research has continued to underscore the remarkably high diversity within the genus Achalinus, which has lead to the discovery of an increasing number of species. However, several factors contribute to the difficulty in accurately identifying snakes of this genus based solely on morphology. Achalinus species display a conservative morphology; sexual dimorphism has been identified (particularly larger TaL/TL in males, more VEN in females, and more SC in males) (
Molecular methods have played a pivotal role in the rapid discovery of Achalinus species (
We thank Sheng-Chao Shi and Shun Ma (Chengdu Institute of Biology, Chinese Academy of Sciences) for their help in formal analysis.
The authors have declared that no competing interests exist.
No ethical statement was reported.
County biodiversity resources survey project in Miao Autonomous County of Chengbu, Hunan Province (no. 2021-326-430529); County Biodiversity Resources Survey Project in Dong Autonomous County of Tongdao, Hunan Province (no. 2021-326-430529); Central Financial Subsidy Project of Jintongshan National Nature Reserve in Hunan Province in 2022 (no. 2022-34).
Hui Li: methodology, formal analysis, validation, writing-original draft, writing-review and editing; Le-Qiang Zhu: methodology, investigation, formal analysis; Bei Xiao: methodology, formal analysis; Jie Huang: methodology, formal analysis; Shao-Wu Wu: methodology, investigation; Li-Xun Yang: methodology, investigation; Zhi-Qiang Zhang: conceptualization, data curation, project administration, resources, supervision, writing-review and editing; Xiao-Yang Mo: conceptualization, data curation, project administration, resources, supervision, writing-review and editing.
Hui Li https://orcid.org/0009-0009-6318-3223
Le-Qiang Zhu https://orcid.org/0009-0006-3820-529X
Bei Xiao https://orcid.org/0009-0006-0740-5360
Jie Huang https://orcid.org/0009-0005-2565-3109
Shao-Wu Wu https://orcid.org/0009-0001-1769-2088
Li-Xun Yang https://orcid.org/0009-0008-3664-5333
Zhi-Qiang Zhang https://orcid.org/0009-0004-8658-9625
Xiao-Yang Mo https://orcid.org/0009-0003-2352-8975
All of the data that support the findings of this study are available in the main text.