A new species of Pareas (Squamata, Pareidae) from southern Vietnam

Abstract

We describe a new species of pareid snake from the Di Linh Plateau in Lam Dong Province of southern Vietnam based on morphological and molecular evidence. Pareas temporalissp. nov. is distinguished from its congeners by having the combination of yellow-brown body colouration; hexagonal-shaped frontal, with lateral sides parallel to the body axis; 16–17 temporals, with 4–5 anterior temporals; loreal and prefrontal not contacting eye; 2–3 preoculars; two suboculars; 2–3 postoculars; 8–9 supralabials; 8–9 infralabials; 15–15–15 dorsal scale rows, all keeled, three vertebral scale rows enlarged; 191 (+1 preventral) ventrals, smooth; 92 subcaudals, all divided; undivided anal scale; two postocular stripes; and a solid dark brown vertebral stripe extending from rear of nuchal collar along the entire length of body and tail. Phylogenetic analyses of mitochondrial DNA data recovered the new species to be nested within the P. carinatus complex and to be the sister taxon to P. nuchalis from Borneo.

An integrative taxonomic revision of slug-eating snakes (Squamata: Pareidae: Pareineae) reveals unprecedented diversity in Indochina

“…However, in this revision the authors did not examine type specimens of P. carinatus , and also have neglected to re-evaluate the status of two available species names currently considered as junior synonyms of P. carinatus : Pareas berdmorei Theobald, 1868, and Amblycephalus carinatus unicolor Bourret, 1934 (see Nguyen, Ho & Nguyen, 2009 ; Wallach, Williams & Boundy, 2014 ; Uetz, Freed & Hošek, 2021 ). The most recent addition to the taxonomy of the group is the discovery of a new species from southern Vietnam – P. temporalis , which was suggested as a sister species to P. nuchalis from Borneo ( Le et al, 2021 ); the authors also provided the most complete phylogeny for the genus Pareas published up to date, generally concordant with the earlier results ( Wang et al, 2020 ; Vogel et al, 2021 ). The taxonomic history of the P. carinatus – P. nuchalis complex is summarized in Table 1 .…”

“…Remark: Until our study this recently discovered species was known only from a single female specimen ( Le et al, 2021 ). In the present work we provide morphological and genetic data for six additional specimens of this species of the both sexes from three previously unkown localities from southern Vietnam (see Fig.…”

“…nov. (ZMMU R-16802); (H) Pareas nuchalis ( Boulenger, 1900 ) (FMNH 131635); (I) holotype of Pareas abros sp. nov. (ZMMU R-16393); (J) male of Pareas temporalis Le et al, 2021 (ZMMU R-13656). Not to scale.…”

“…The examined comparative material is listed in Appendix S2 . For comparison with other taxa, we also relied on previously published data ( e.g ., Theobald, 1868b ; Bourret, 1934 ; Pope, 1935 ; Smith, 1943 ; Taylor, 1965 ; Guo & Zhao, 2004 ; Guo & Deng, 2009 ; Stuebing, Inger & Lardner, 2014 ; You, Poyarkov & Lin, 2015 , Vogel, 2015 ; Hauser, 2017 ; Wang et al, 2020 ; Vogel et al, 2020 , 2021 ; Ding et al, 2020 ; Bhosale et al, 2020 ; Liu & Rao, 2021 ; Le et al, 2021 ). Other abbreviations used: Prov.…”

“…Several recent taxonomic studies have demonstrated that the species diversity of Pareinae is still underestimated ( e.g ., Vogel, 2015 ; Hauser, 2017 ; Quah et al, 2019 , 2020 ; Quah, Lim & Grismer, 2021 ; Le et al, 2021 ). The high degree of morphological similarity among closely related taxa of Pareinae often makes species delineation in slug snakes quite challenging ( Guo & Deng, 2009 ; Vogel, 2015 ; Yang et al, 2021 ), suggesting that the molecular data represent an effective tool to help untangle taxonomic controversies when morphological analyses yield inconsistent results ( You, Poyarkov & Lin, 2015 ; Loredo et al, 2013 ; Vogel et al, 2020 , 2021 ; Bhosale et al, 2020 ; Wang et al, 2020 ; Ding et al, 2020 ; Liu & Rao, 2021 ; Yang et al, 2021 ).…”