Identification of the taxonomic status of Scinax nebulosus and Scinax constrictus (Scinaxinae, Anura) based on molecular markers

Abstract

The validation of many anuran species is based on a strictly descriptive, morphological analysis of a small number of specimens with a limited geographic distribution. The Scinax Wagler, 1830 genus is a controversial group with many doubtful taxa and taxonomic uncertainties, due a high number of cryptic species. One example is the pair of species Scinax constrictus and Scinax nebulosus, which share a similar morphology. Scinax constrictus is restricted to the Brazilian Cerrado savanna, while S. nebulosus is widely distributed throughout northern South America. Despite the validation of many anuran species, discriminations based only on morphological traits is quite difficult due to the high conservative morphology of some groups. In this context, the present study uses mitochondrial and nuclear genes to provide a more consistent diagnosis and test the validity of S. constrictus as a distinct species from S. nebulosus, as well as evaluate the position of these taxa within the Scinax genus. The topologies obtained herein uphold the monophyletic status of Scinax based on all molecular markers assessed in this study, in all analytical approaches, with high levels of statistical support.

Treefrog Diversity in the Neotropics: Phylogenetic Relationships of Scinaxini (Anura: Hylidae: Hylinae)

“… 13 This is congruent with the results of Freitas et al (2020), who identified three lineages under the name Scinax nebulosus , one of which corresponds to S. constrictus . GenBank accessions are not informed in the publication.…”

“…We located the 16S sequences produced for that study in GenBank, but not the COI sequences. Unfortunately, it is not possible to associate the information provided in the text of Freitas et al (2020) with that annotated on the 16S sequences. For that reason, we did not include these in our definitive data set.…”

Posição taxonômica de duas populações relacionadas à >i<Scinax squalirostris>/i< (Lutz, 1925) (Anura: Hylidae)

“…Há várias espécies de Scinax que apresentam a morfologia externa altamente conservada (e.g. Fonte, 2010;Nunes et al, 2012;Brusquetti et al, 2014;Bang & Giaretta, 2017;Araujo-Vieira et al, 2020;Freitas et al, 2020;Novaes-e-Fagundes et al, 2021;Ferrão et al, 2022), o que torna tarefas taxonômicas no grupo complexas, acarretando assim nesse cenário no qual várias linhagens aguardam descrição formal. O intricado histórico taxonômico do gênero (Faivovich, 2002;Araujo-Vieira et al, 2020), bem como a falta de informações precisas sobre a distribuição de algumas espécies e a subamostragem de determinadas regiões (Ferrão et al, 2016), são fatores que também influenciam esse cenário.…”