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| Hebius malnatei Li, Nguyen, Huang, Poyarkov, David, Li & Ren, in M.-L. Li, Nguyen, Huang, Idiiatullina, Le, Poyarkov, David, Han, Wu, J.-T. Li et Ren, 2026. |
Abstract
Hebius atemporalis (Bourret, 1934) has been reported from both northern Vietnam and southern China. Previous studies revealed deep genetic divergence between the Chinese and Vietnamese populations; however, no comprehensive taxonomic revision has examined the phylogenetic relationships and taxonomic status of these divergent lineages. Here, we present an integrative taxonomic reassessment of the H. atemporalis complex, combining detailed morphological comparisons and molecular data. As a result, we identify and describe a distinct new species, Hebius malnatei sp. nov., endemic to the Yunnan-Guizhou Plateau, China. The new species can be distinguished from H. atemporalis sensu stricto by its larger adult body size, shorter relative tail length, higher numbers of ventrals and subcaudals, and distinctive coloration characterized by the absence of a nuchal collar. Phylogenetic analyses based on cytochrome b sequences consistently recover Hebius malnatei sp. nov. as the sister taxon of H. atemporalis s. str., with uncorrected p-distances of 8.0–9.8%. According to the IUCN Red List criteria, we recommend assigning Hebius malnatei sp. nov. to the category Least Concern (LC). This study highlights the need for taxonomic revision of widely distributed Hebius species and underscores the role of the Yunnan-Guizhou Plateau uplift in promoting species diversification.
Key Words: Cryptic diversity, cytochrome b, morphology, taxonomy, Yunnan-Guizhou Plateau
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| Photographs in life of Hebius malnatei sp. nov. from China: CIB 122551, Pugu, Panzhou, Liupanshui, Guizhou (A); CIB 122558, Heilongtan Park, Kunming, Yunnan (B, C); Mengzi, Yunnan (D); Pugu, Panzhou, Liupanshui, Guizhou (E). Photographs by J.J. Huang (A) and M. L. Li (B–E). |
Hebius malnatei Li, Nguyen, Huang, Poyarkov, David, Li & Ren, sp. nov.
Diagnosis. Hebius malnatei sp. nov. is distinguished from all congeners by the following combination of characters: (1) small body size, maximum snout-vent length 416 mm; (2) head small, narrow, and moderately distinct from neck; (3) maxillary teeth 26–29, gradually enlarged posteriorly; (4) supralabials 6 (rarely 5), with the 3rd and 4th entering the orbit; (5) temporal scale absent or represented by a small narrow scale; (6) infralabials 7 (rarely 6); (7) dorsal scale rows 17-17-17, weakly keeled except for the outermost 1–6 rows; (8) ventrals 146–156 with two preventrals; (9) subcaudals 60–70, paired; (10) ventral surface of head white, scattered with black spots or streaks; (11) sutures of infralabials strongly edged in black; (12) a white to orangish nuchal collar absent; (13) dorsal ground color gradually changing from brown to dark olive, usually with a series of discontinuous light spots along the lateral side, forming an inconspicuous stripe; (14) tail relatively short (TaL/SVL ratio 0.22–0.27).
Etymology. The specific epithet malnatei is a patronym in genitive declension honoring Edmond V. Malnate (1916–2003), an American herpetologist who made significant contributions to the taxonomy and systematics of Asian colubrid snakes, especially within Natricidae, and who first revised the taxonomic placement of Hebius atemporalis.
We recommend the following common names for this species: English: “Malnate’s Keelback”, Chinese (中文): “云贵腹链蛇” (Yún Guì Fù Liàn Shé) for its restricted distribution to Yunnan-Guizhou Plateau. Vietnamese: “Rắn sãi Man-lát”, French: “Couleuvre aquatique de Malnate”, Russian (Русский): “Лесной уж Мэлнейта” (Lesnoy Uzh Melneyta).
Distribution. Hebius malnatei sp. nov. is likely endemic to China, with its known range restricted to the Yunnan-Guizhou Plateau at elevations of 1,750–1,950 m a.s.l. (Fig. 5).
Mao-Liang Li, Tan Van Nguyen, Jun-Jie Huang, Sabira S. Idiiatullina, Son Xuan Le, Nikolay A. Poyarkov, Patrick David, Bu-Ying Han, Wei Wu, Jia-Tang Li and Jin-Long Ren. 2026. Taxonomic Reassessment of Hebius atemporalis (Bourret, 1934) (Squamata, Natricidae), with the Description of A New Species from China. Zoosystematics and Evolution. 102(1): 235-251. DOI: doi.org/10.3897/zse.102.176342