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Achalinus mirabilis Xu, Hu, Qi, Zhang, Zhou, Xu, Wang & Peng,
in Y. Xu, Hu, Qi, Ma, Chen, T. Zhang, Y. Zhang, Sun, Zhou, J. Xu, Wang et Peng. 2026. |
Abstract
The taxonomy of Achalinus jinggangensis has long remained unclear due to limited sampling and the consequent lack of publicly available molecular and distributional data. Here, we re-evaluate the taxonomic status of A. jinggangensis using an integrative approach that combines molecular phylogenetic analyses, detailed morphological comparisons, and direct examination of type material, and provide a comprehensive redescription of this species. In addition, we describe an unexpected new species from Kuocang Mountain, Linhai City, Zhejiang Province, China, Achalinus mirabilis sp. nov. Phylogenetic analyses indicate that Achalinus mirabilis sp. nov. appears to be most closely related to A. jinggangensis, although this relationship is not statistically supported, and exhibits substantial genetic divergence, as indicated by uncorrected p-distances of 9.5%–10.9% in the CO1 gene fragment. Morphologically, the new species is readily distinguished from A. jinggangensis by its distinctly keeled outermost dorsal scale row, a higher number of ventral scales in both sexes, and conspicuous differences in coloration. Our results highlight previously underestimated species diversity within Achalinus and refine the current understanding of its taxonomy. This study increases the number of recognized species in the genus Achalinus to 30, and underscores the importance of integrative approaches in resolving cryptic diversity and taxonomic complexity within the genus.
Key Words: Achalinus mirabilis sp. nov., Kuocang Mountain, molecular phylogeny, morphological characters, taxonomy
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Coloration of the holotype of Achalinus mirabilis sp. nov. in life (QHU R2025051, adult female).
A. Dorsolateral view; B. Ventral view of the body. Photographs by J.H. Hu. |
Achalinus mirabilis Xu, Hu, Qi, Zhang, Zhou, Xu, Wang & Peng, sp. nov.
Diagnosis. The new species Achalinus mirabilis sp. nov. is distinguished from all of its congeners by a combination of the following morphological characters: (1) size medium, with a maximum SVL of 270 mm in males and 332 mm in females; (2) tail relatively short, TAL/TL ratio 0.22 in males and 0.17–0.18 in females; (3) loreal scale absent; (4) length of suture between internasals substantially longer than that between prefrontals, LSBI/LSBP ratio 1.60–3.35; (5) dorsal scales strongly keeled, arranged in 23 rows throughout the body, with the outermost row also strongly keeled and substantially enlarged; (6) infralabials 6, with the anterior three or four in contact with the first pair of chin shields; (7) two pairs of chin shields; (8) maxillary teeth 27 based on the only counted female specimen; (8) ventral scales 163–166 in males and 174–178 in females; (9) subcaudals 64–68 in males and 53–56 in females, not paired; (10) in life, the dorsum is brown to dark brown with a slight metallic sheen, and the venter is uniformly light brown.
Etymology. The specific epithet mirabilis represents a Latin adjective in nominative singular, meaning “marvelous” or “remarkable”, and is given in reference to the distinctive morphology of this species within the genus Achalinus. In addition, the discovery of a previously unrecorded new species in Taizhou City, Zhejiang Province, a highly urbanized and economically developed region, was also unexpected. Based on its known distribution, Kuocang Mountain (Kuocangshan) in Linhai City, Taizhou City, Zhejiang Province, China, we propose the Chinese common name “括苍山脊蛇” (Kuò Cāng Shān Jǐ Shé) and the English common name “Kuocang Moutain odd-scaled snake”.
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Live or fresh specimens of paratypes of Achalinus mirabilis sp. nov.
A. SMNH 20250126, subadult male; B. QHU R2025053, adult male;
C. QHU R2025054, adult female; D. SYS r003125, adult female.
Photographs by J.H. Hu (A–C) and H.J. Chen (D). |
Yuhao Xu, Jiahao Hu, Shuo Qi, Shun Ma, Haojun Chen, Tierui Zhang, Yunfei Zhang, Fanyue Sun, Jiajun Zhou, Jinan Xu, Yingyong Wang, Lifang Peng. 2026. Taxonomic Reassessment of
Achalinus jinggangensis (Zong & Ma, 1983) (Serpentes, Xenodermidae), with Description of A New Species from Zhejiang Province, China.
Zoosystematics and Evolution. 102(2): 387-409. DOI:
doi.org/10.3897/zse.102.183453
