Conflicting relationships of Vipera walser inferred from nuclear genes sequences and mitochondrial DNA

Abstract

The description of Vipera walser from the Northern Italian Alps as a new species (Ghielmi et al., 2016, Journal of Zoological Systematics and Evolutionary Research, 54, 161) was one of the most unexpected surprises of European herpetology in the 21st century. In mitochondrial (mt) DNA, it is closely related to a group of vipers only present in the Caucasus region and Northeastern Anatolia. However, its morphology is similar to the V. berus populations that inhabit nearby mountains in the Swiss‐Italian Alps, which raises questions on its relationships and status. We thus sequenced five nuclear (nu) genes to determine the position of V. walser relative to V. berus and to the Caucasian/Northeastern Anatolian vipers in nuDNA. We also reanalyzed five previously sequenced mtDNA fragments. NuDNA markers recovered V. walser as closely related to Italian populations of V. berus and not to the Caucasian/Anatolian species, thus contradicting the mtDNA phylogeny. We checked that each of the five mtDNA fragments independently amplified by Ghielmi et al. (2016, Journal of Zoological Systematics and Evolutionary Research, 54, 161) produced individual gene trees compatible with the concatenated mtDNA phylogeny, thus excluding the hypothesis that NUMTs sequencing generated the mtDNA relationships reported by Ghielmi et al. (2016, Journal of Zoological Systematics and Evolutionary Research, 54, 161). Given the low level of nuclear differentiation between V. walser and the Italian population of V. berus, we argue that ancient admixture between V. berus and the ancestral population of V. walser is the most likely explanation for this case of cyto‐nuclear discordance and we discuss the consequences of these results on the systematic status of V. walser.

A Guide to the Clinical Management of Vipera Snakebite in Italy

“…In light of the recent comprehensive review on the Vipera species of major medical relevance in Europe provided by Di Nicola et al [ 14 ], we present herein a concise overview of the venom components and main activities exhibited by the four Vipera species present in Italy, namely V. ammodytes , V. aspis , V. berus , and V. ursinii . Considering that Speybroeck et al [ 31 ] deemed it premature to accept the species status of the recently described Walser viper, Vipera walser (see [ 32 ]) due to the potential existence of cyto-nuclear discordance, which has been confirmed by Doniol-Valcroze et al [ 33 ], in this study we regard this taxon as a subspecies of V. berus . This classification aligns with the the findings of a recent phylogenomic analysis of the diversity of Palearctic vipers [ 34 ], the latest checklist of the Italian herpetological fauna [ 35 ] and the updated dichotomous key for European snakes [ 36 ].…”

Acute compartment syndrome and fasciotomy after a viper bite in Italy: a case report

“…1 A). Two species of viper inhabit the locality where the incident occurred: the common viper ( Vipera aspis ) and the recently described Vipera walser [ 13 ], an adder whose taxonomic status is still uncertain [ 9 , 29 ]. Although the species responsible for the envenomation remains undetermined, the habitat in the area (alpine prairie with Rhododendron scrubs) is compatible with the presence of Vipera walser (personal observations).…”

Maps of area of habitat for Italian amphibians and reptiles

“…All species live in terrestrial/freshwater habitats, excluding cave habitats. An additional range was added for Vipera walser, a recently described endemic taxon of viper which only occurs in a narrow area in northern Italy (Ghielmi et al 2016; see also Doniol-Vacroze et al 2021 for additional taxonomic discussion) The range of V. walser was obtained from Ficetola et al (2020). As a taxonomic reference, we relied on two databases: AmphibiaWeb (amphibiaweb.com) for amphibian species and The reptile Database (Uetz et al 2021, http://www.reptile-database.org) for reptile species.…”