Taxonomic revision of the genus Xenopholis Peters, 1869 (Serpentes: Dipsadidae): Integrating morphology with ecological niche

Abstract

A reliable identification and delimitation of species is an essential pre-requisite for many fields of science and conservation. The Neotropical herpetofauna is the world’s most diverse, including many taxa of uncertain or debated taxonomy. Here we tackle one such species complex, by evaluating the taxonomic status of species currently allocated in the snake genus Xenopholis (X. scalaris, X. undulatus, and X. werdingorum). We base our conclusions on concordance between quantitative (meristic and morphometric) and qualitative (color pattern, hemipenes and skull features) analyses of morphological characters, in combination with ecological niche modeling. We recognize all three taxa as valid species and improve their respective diagnosis, including new data on color in life, pholidosis, bony morphology, and male genitalia. We find low overlap among the niches of each species, corroborating the independent source of phenotypic evidence. Even though all three species occur in the leaf litter of distinct forested habitats, Xenopholis undulatus is found in the elevated areas of the Brazilian Shield (Caatinga, Cerrado and Chaco), whereas X. scalaris occurs in the Amazon and Atlantic rainforests, and X. werdingorum in the Chiquitanos forest and Pantanal wetlands. We discuss the disjunct distribution between Amazonian and Atlantic Forest snake species in the light of available natural history and ecological aspects. This study shows the advantages of combining multiple data sources for reliable identification and circumscription of ecologically similar species.

ATTEMPTED PREDATION OF Physalaemus erikae (ANURA, LEPTODACTYLIDAE) BY Xenopholis scalaris (WUCHERER, 1861; COLUMBRIDAE) IN THE SOUTHERN BAHIA, BRAZIL.

“…Xenopholis scalaris (Wucherer, 1861) has a wide distribution in the Amazon Forest, in Bolivia, Peru, Ecuador, Colombia and Brazil, in the states of Amazonas, Pará, Mato Grosso, Rondônia, with occurrences in the Atlantic Forest in the southern region of the state of Bahia, and in the states of Pernambuco, Alagoas, Rio de Janeiro and São Paulo. It inhabits primary and secondary forests in humid environments (Ringler et al, 2010, Vieira et al, 2012, Powell et al, 2016, França et al, 2019, Gomes et al, 2020 and shows an opisthoglyph dentition. This species is found mainly in the leaf litter on the ground (Ringler et al, 2010;Mendes et al, 2013) where it forages mainly during the night (Ringler et al, 2010).…”