Patrick David

Two species of Indian pit vipers, Coluber gramineus Shaw, 1802 and Coluber viridis Bechstein, 1802 were described the same year based on the same holotype. Coluber gramineus has subsequently been considered the valid nomen of the Indian species now known as Craspedocephalus gramineus. We here demonstrate that, in fact, Coluber viridis Bechstein, 1802 was published before Coluber gramineus Shaw, 1802 and would have priority if the Principle of Priority was strictly followed. For preserving the stability of the systematics of Asian pit vipers, we take the suitable nomenclatural action to protect the nomen Coluber gramineus Shaw, 1802 (nomen protectum or mnemokyronym) and to render Coluber viridis Bechstein, 1802 a nomen oblitum (lethakyronym). We also discuss the status of Vipera viridis Daudin, 1803, based on the same specimen previously designated as its lectotype (lectonymophoront) and the uses of the species nomen viridis in the literature.

A new species of the genus Ovophis Burger in Hoge & Romano-Hoge, 1981, is described from the Langbian Plateau, southern Vietnam, based on an integrative taxonomic approach combining morphological and molecular evidence. Ovophis langbianus sp. nov . is distinguished from its congeners by a unique combination of diagnostic morphological characters and by significant genetic divergence in the mitochondrial cytochrome b gene. Phylogenetic analyses recover the new species as the sister lineage of O. tonkinensis (Bourret), from which it differs in body proportions, head morphology, color pattern, and several meristic characters. Multivariate analyses of morphological variation further support the distinctiveness of the new species, with specimens of Ovophis langbianus sp. nov . and O. tonkinensis forming two well-separated groups in morphospace and exhibiting significant differences in centroid positions. The new species is currently known only from montane evergreen forests of the Langbian Plateau at elevations of approximately 800–2,230 m asl. The recognition of Ovophis langbianus sp. nov . further emphasizes the taxonomic complexity of the O. tonkinensis species group and, together with previous molecular evidence for a distinct Cao Bang (Vietnam)-Guangxi (China) lineage, highlights the need for a comprehensive reassessment of species boundaries within the complex.

Calamaria pavimentata Duméril, Bibron & Duméril, 1854 was originally described from Java Island, Indonesia, yet specimens from southern China, particularly Guangxi, have long been referred to this species based on general morphological resemblance. Herein, the taxonomic status of Chinese populations previously referred to as Calamaria pavimentata is re-evaluated using an integrative approach combining morphological data and mitochondrial DNA analyses, based on four specimens from Yangjiang City, Guangdong Province, and Chongzuo City, Guangxi Zhuang Autonomous Region, China. Phylogenetic analyses recover the Chinese specimens as a distinct and well-supported lineage within Calamaria . Notably, the Guangdong and Guangxi populations exhibit a relatively high intraspecific mitochondrial divergence (uncorrected p -distance = 10.78% based on the cytochrome b gene), despite the absence of consistent diagnostic morphological differences. Although mitochondrial DNA data from topotypic C. pavimentata , are currently unavailable, the observed morphological differences, together with the pronounced geographic disjunction between Java and southern China, support the recognition of the Chinese population as a distinct species, herein described as Calamaria similis sp. nov . from Guangdong and Guangxi, China. Detailed morphological examinations reveal that Calamaria similis sp. nov . differs from C. pavimentata and all of its currently recognized synonyms by having higher ventral scale counts in females, fewer subcaudal scales in males (but slightly more in females), a smaller maximum total length in males, and a shorter relative tail length in both sexes. Our results highlight the need for renewed field surveys in Java Island, Indonesia to rediscover C. pavimentata sensu stricto, and emphasize that other populations previously identified as C. pavimentata should be re-evaluated using integrative taxonomic approaches.

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.

The reed snakes of the genus Calamaria H. Boie in F. Boie are among the least-studied Southeast Asian snakes, with several taxa known only from their original description. Calamaria pavimentata annamensis Bourret, 1937, described from “Dong Tam Ve (province de Quang-tri), Annam”, now Bac Huong Hoa Nature Reserve, Quang Tri Province, Vietnam, based solely on a single specimen. This taxon was subsequently treated as a junior synonym of C. pavimentata Duméril, Bibron & Duméril, for example by Smith (1943) and Inger & Marx (1965), without any comprehensive reassessment to date. Here, we report the rediscovery of this taxon based on three newly collected specimens from the type locality and revalidate it as Calamaria annamensis stat. nov., based on integrative morphological and mitochondrial DNA analyses. We established detailed morphological comparisons to specimens of C. pavimentata alleged to originate from Java Island, Indonesia (type locality), and from Guangxi Province, China (as defined by Yeung et al. 2022), and other congeners from mainland Southeast Asia. Mitochondrial DNA (cytochrome b) analysis supports the distinctiveness of Calamaria annamensis stat. nov., revealing an uncorrected p-distance of 19.4% from C. pavimentata and ranging from 16.7% (C. nebulosa Lee) to 21.5% (C. lumbricoidea Boie) when compared with other congeners. This revalidation increases the number of Calamaria species to 71, of which twelve are currently recorded from Vietnam. Our findings also underscore the urgent need for comprehensive taxonomic and molecular studies on the widely distributed Calamaria pavimentata and C. septentrionalis Boulenger species complexes in Vietnam to resolve their true diversity and distribution.

Lycodon irwini Naveen, Zeeshan, Mirza, Choure & Chandramouli, 2025 was recently described from three female specimens collected in the Nicobar Islands, India. Until now, no male individuals had been reported, leaving potential sexual dimorphism and several diagnostic characters insufficiently understood. Here, we provide the first morphological description of the male and refine the species diagnosis using information from both sexes. In addition, an updated identification key to the species of the Lycodon subcinctus complex is presented. We also compile an updated checklist of 74 species of amphibians and reptiles recorded from the Nicobar Islands.

We report the rediscovery of the keelback snake Rhabdophis angeli (Bourret, 1934) from its type locality in Tam Dao National Park, Phu Tho Province, Vietnam, nearly 90 years after its original description. Based on an integrative approach combining morphological examination and molecular phylogenetic analyses, we revise the diagnosis of Rhabdophis angeli and formally synonymise Rhabdophis guangdongensis Zhu, Wang, Takeuchi & Zhao, 2014, with R. angeli. Given the current distributional data, made of widely scattered localities, and the presence of potential threats, we recommend that Rhabdophis angeli be categorised as Near Threatened (NT) under the IUCN Red List criteria. This study highlights the importance of comprehensive taxon sampling, particularly in adjacent regions, to improve our understanding of species boundaries and conservation status. An updated identification key is provided for species within the Rhabdophis nuchalis group, highlighting the need for further integrative taxonomic work in this complex.

A new species of the genus Hebius is described from Yunnan Province, China. The new species was previously identified as H. boulengeri, but it can be separated from H. boulengeri and other species of this genus by a combination of the following characters: 19-19-17 dorsal scale rows, 148–155 ventrals, 90–105 subcaudals, one preocular, three postoculars, 23–25 maxillary teeth, a distinct continuous white streak from posteroventral margin of eye extending backward and upward to nape to connect with dorsolateral stripe on each side, and white venter. The genetic divergence between the new species and H. boulengeri was 6.6% and the genetic divergences between the new species and other congeners ranged from 6.8% to 15.9% in the mitochondrial cytochrome b gene.

A new species of the genus Gonyosoma Wagler is described from Vietnam and Laos, based on an integrative approach combining morphological and molecular evidence. Gonyosoma iadinum sp. nov. is distinguished from its congeners by a unique combination of diagnostic characters. It differs from its morphologically closest relative, Gonyosoma coeruleum Liu, Hou, Lwin, Wang & Rao, in the structure of the cloacal plate and hemipenes, as well as in significant genetic divergence in the cytochrome b (cyt b) mitochondrial DNA (mtDNA) gene sequences (p > 8.1%). The new species is currently known from central and southern Vietnam and central and southern Laos, where it has been recorded in montane evergreen forests of the Kon Tum-Gia Lai Plateau and the Langbiang Plateau in Vietnam. In Laos, it has been documented in Khammouan Province and the Bolaven Plateau. The species inhabits elevations ranging from 655 to 1,550 m above sea level. Further studies are required to reassess the taxonomic status of the Gonyosoma prasinum complex, particularly in Hainan Island, China. Based on its known distribution and available data, we suggest that the new species should be classified as Least Concern (LC) under the IUCN Red List criteria. We also provide an updated taxonomic key for the Gonyosoma species.