Systematics of Trimeresurus popeiorum Smith, 1937 with a revised molecular phylogeny of Asian pitvipers of the genus Trimeresurus Lacépède, 1804 sensu lato

Abstract

The pit viper snake genus Trimeresurus Lacépède, 1804 sensu lato, is a diverse group of nocturnal serpents comprising over 61 species. The genus is morphologically heterogeneous and has been divided into several subgenera. We present an updated phylogeny of Asian pitvipers and propose a revised classification. Additionally, we revise the taxonomy of T. popeiorum Smith, 1937 and propose taxonomic changes with support from molecular and morphological data. We restrict T. popeiorumsensu stricto to northeastern India, Bangladesh, southern China, and northern Myanmar; populations beyond these areas require further assessment. We also synonymize T. yingjiangensisChen et al., 2019 with T. popeiorum based on overlapping morphological characters, molecular data, and distribution. The findings shed new light on the taxonomy of T. popeiorum, warranting the need for assessing the population of T. popeiorum from southeast Asia.

Another new species of karst-associated pitviper (Serpentes, Viperidae: Trimeresurus) from the Isthmus of Kra, Peninsular Thailand

“…Following the description of Trimeresurus kraensis sp. nov., the subgenus Trimeresurus, as defined by Mirza et al (2023) and Idiiatullina et al (2023), currently includes 23 species namely, Trimeresurus albolabris, T. andersonii, T. cantori, T. cardamomensis, T. ciliaris, T. caudornatus, T. davidi, T. erythrurus, T. fasciatus, T. guoi, T. honsonensis, T. insularis, T. kanburiensis, T. kraensis sp. nov., T. kuiburi, T. labialis, T. macrops, T. mutabilis, T. purpureomaculatus, T. rubeus, T. salazar, T. septentrionalis, and T. venustus (Sumontha et al 2021;Mirza et al 2023;Poyarkov et al 2023).…”

“…nov., the subgenus Trimeresurus, as defined by Mirza et al (2023) and Idiiatullina et al (2023), currently includes 23 species namely, Trimeresurus albolabris, T. andersonii, T. cantori, T. cardamomensis, T. ciliaris, T. caudornatus, T. davidi, T. erythrurus, T. fasciatus, T. guoi, T. honsonensis, T. insularis, T. kanburiensis, T. kraensis sp. nov., T. kuiburi, T. labialis, T. macrops, T. mutabilis, T. purpureomaculatus, T. rubeus, T. salazar, T. septentrionalis, and T. venustus (Sumontha et al 2021;Mirza et al 2023;Poyarkov et al 2023). Within this group, the members of the T. kanburiensis and T. macrops species complexes do not form reciprocally monophyletic clades but form a strongly supported monophylum with poorly resolved phylogenetic relationships within it.…”

“…The genus Trimeresurus Lacépède, 1804 currently comprises 47 species of Asian pitvipers after the recent description of Trimeresurus ciliaris by Idiiatullina et al (2023). This latter species belongs to the complex of species of Trimeresurus kanburiensis Smith, 1943, which currently includes four species from Southeast Asia, namely: T. ciliaris Idiiatullina, Pawangkhanant, Tawan, Worranuch, Dechochai, Suwannapoom, Nguyen, Chanhome & Poyarkov, 2023, T. kanburiensis, T. kuiburi Sumontha, Suntrarachun, Pauwels, Pawangkhanant, Chomngam, Iamwiriyakul & Chanhome, 2021, and T. venustus Vogel, 1991 Based on molecular phylogenies, the recent papers by Mirza et al (2023) and Idiiatullina et al (2023) demonstrated that the complex of T. kanburiensis forms a distinct clade in the subgenus Trimeresurus together with the complex of Trimeresurus macrops, which currently includes four species, namely: T. cardamomensis (Malhotra, Thorpe, Mrinalini & Stuart, 2011), T. honsonensis (Grismer, Ngo & Grismer, 2008), T. macrops Kramer, 1977 and T. rubeus (Malhotra, Thorpe, Mrinalini & Stuart, 2011). The systematic status of this clade will be discussed elsewhere in the frame of a revision of the whole complex of Trimeresurus s.…”

“…The systematic status of this clade will be discussed elsewhere in the frame of a revision of the whole complex of Trimeresurus s. lat., namely in including other subgenera recognized by Mirza et al (2023) and Idiiatullina et al (2023).…”

New country record of Trimeresurus uetzi Vogel, Nguyen & David, 2023 (Reptilia: Squamata: Viperidae) from India

“…Morphologically, one adult male of the examined museum specimens collected from Mizoram University campus (23.7384°N; 92.6642°E; 822 m; Figure 1) did not match with the taxonomic features of other Trimeresurus species, which were already confirmed from Mizoram State and adjacent regions. MZMU 3333 differs from regional congeners in having Ven 165 versus 159-164 in male T. caudornatus Chen, Ding, Vogel and Shi, 2020, MSR 21 vs 23 (24, 25) in male T. erythrurus (Cantor 1839); ventrolateral stripes and a postocular stripe present vs absent, iris copper vs firebrick-red or deep red in males T. guoi Chen, Shi, Vogel & Shi, 2021; ventrolateral stripe white vs stripe bicolor (red and white), Ven 165 vs 157-162, and Sc 69 vs 54-67 in males T. mayaae Rathee, Purkayastha, Lalremsanga, Dalal, Biakzuala, Muansanga & Mirza, 2022, and 10 cephalic scales feebly keeled between the supraoculars vs 11-13, iris copper coloured vs red to deep red, and ventrolateral stripes and a postocular stripe present vs absent in males of T. popeiorum Smith, 1937(see also Mathew 2007Lalremsanga et al 2011;Mirza et al 2023;Vogel et al 2023;Idiiatullina et al 2024). Instead, it is in agreement with the diagnostic features of the recently described T. uetzi as provided in the original description (Vogel et J TT dorsum and yellowish-green venter; a white postocular streak from the anterior margin of the nasal scale that connects posteriorly to the white dorsolateral stripe at the corner of the mouth, plus lack of red stripes on facial and ventrolateral regions.…”