A new pit viper of the genus Trimeresurus (Lacépède, 1804) (Squamata: Viperidae) from Southwest China

Abstract

The white-lipped tree viper, Trimeresurus albolabris Gray, is one of the most common species of the genus Trimeresurus with a wide distribution from India eastwards to China and southwards to Indonesia. However, this species was previously split into five geographical clades with significant genetic divergence. Recent surveys in Yingjiang County, Yunnan Province, China resulted in the discovery of one cryptic species of the subgenus Trimeresurus. Combining molecular, morphological and ecological data, we describe it as a new species Trimeresurus caudornatus sp. nov. The new species differs from other Trimeresurus species by a combination of the following characteristics: (1) Head and body generally dark green, postocular stripes absent in both genders, upper labials light green; (2) ventrolateral stripe faint green yellow, present on the first row of DSR in both genders; (3) iris golden yellow in both genders; (4) dorsal tail mostly dark red, lateral and ventral green; an orange red stripe along the ventral part of the tail; (5) DSR 21/22 –21–15, VEN 161–163, SC 52–72; (6) first upper labial partially fused to the nasal. The new species was shown to be a strongly supported monophyletic group (BPP 100%) and sister to T. septentrionalis. The uncorrected pairwise distances of mitochondrial gene Cytb between the new species and other species of the subgenus Trimeresurus, ranging from 0.059 (T. septentrionalis) to 0.134 (T. kanburiensis).

On further specimens of the Pit viper Trimeresurus erythrurus (Cantor, 1839) (Squamata: Viperidae), with description of a topotype and range extension to the Godavari Basin, peninsular India

“…Our finding of T. erythrurus -an essentially northeast Indian and the Indo-Burmese species (Gumprecht et al, 2004;Whitaker and Captain, 2004;Vogel, 2006;Ahmed et al, 2009;Wallach et al, 2014, Chen et al, 2020Mirza et al, 2020) in the southern reaches of eastern India from the Godavari Basin may come as a surprise. The Coringa Wildlife Sanctuary, though small, is situated near Kakinada close to the famous Vishakapatnam city.…”

Phylogeography of mangrove pit vipers (Viperidae, Trimeresurus erythrurus‐purpureomaculatus complex)

“…Museum voucher abbreviations are as follow: CAS = California Academy of Sciences; LSUHC = La Sierra University Herpetological Collection; ZRC = Zoological Reference Collection, Lee Kong Chian Natural History Museum; ZMKU = Zoological Museum, Kasetsart University, Thailand. Samples were strategically selected from distinct localities to maximize geographic coverage with specific emphasis on the Trimeresurus erythrurus and T. purpureomaculatus complex (Figure 2), both of which are currently understood to be paraphyletic (Chen et al, 2020; Malhotra & Thorpe, 2004; Zhu et al, 2016). The 12S, 16S, cytochrome b (Cyt b), and NADH dehydrogenase subunit 4 (ND4) mitochondrial genes were sequenced using the primers and protocol listed in Chen et al (2020).…”

“…Samples were strategically selected from distinct localities to maximize geographic coverage with specific emphasis on the Trimeresurus erythrurus and T. purpureomaculatus complex (Figure 2), both of which are currently understood to be paraphyletic (Chen et al, 2020; Malhotra & Thorpe, 2004; Zhu et al, 2016). The 12S, 16S, cytochrome b (Cyt b), and NADH dehydrogenase subunit 4 (ND4) mitochondrial genes were sequenced using the primers and protocol listed in Chen et al (2020). In total, 32 new sequences were generated for this study.…”

“…In the Ayeyarwady Delta (Ayeyarwady Division) and swamp forest surrounding Hlawga Lake (Yangon Division), snakes exhibit a range of phenotypes from bright green with no dorsal markings such as in T. erythrurus , to greyish green with no markings, or greyish‐green and yellow with distinct dark blotches (Figures 1 and 2; Leviton et al, 2003)—these “green” variants are not known to occur anywhere else ( T. purpureomaculatus is grey or brownish in other parts of its distribution). Moreover, phylogenetic studies employing molecular data have demonstrated that T. purpureomaculatus is paraphyletic with respect to T. erythrurus (Chen et al, 2020; Malhotra & Thorpe, 2004; Zhu et al, 2016). The overlapping distributions, drastic colour polymorphisms, and paraphyly of T. purpureomaculatus indicate that these two species form an unresolved monophyletic species complex that is poorly understood.…”

“…2), both of which are currently understood to be paraphyletic (Chen et al, 2020;Malhotra & Thorpe, 2004;Zhu et al, 2016). The 12S, 16S, cytochrome b (Cyt b), and NADH dehydrogenase subunit 4 (ND4) mitochondrial genes were sequenced using the primers and protocol listed in Chen et al (2020). In total, 32 new sequences were generated for this study.…”