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

N. M. Piorski,L. N. Weber,J. B. L. Sales,I. Sampaio,T. M. B. Freitas

doi:10.1590/1519-6984.225646

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.

Highlights

Phylogenetic systematics seeks evidence on the evolutionary relationships among species in order to comprehend diversity patterns (Lourenço et al, 2015)
Neotropical amphibians present relatively conserved morphological characteristics and, in many cases, reliable diagnostic traits are difficult to identify (Nogueira et al, 2016), which often implies the existence of cryptic species, which have been increasingly identified in recent years (Guarnizo et al, 2015; Pinto et al, 2019)
The greatest genetic distance was recorded for the COI marker (Table 2), with a divergence of 12.7% between S. nebulosus and S. constrictus

Summary

Introduction

Phylogenetic systematics seeks evidence on the evolutionary relationships among species in order to comprehend diversity patterns (Lourenço et al, 2015). Neotropical amphibians present relatively conserved morphological characteristics and, in many cases, reliable diagnostic traits are difficult to identify (Nogueira et al, 2016), which often implies the existence of cryptic species, which have been increasingly identified in recent years (Guarnizo et al, 2015; Pinto et al, 2019). This means that the species-level diversity of many genera has long been underestimated. Almost half of these species (338 species in 27 genera) are found in Brazil (Frost, 2017)

Methods

Results

Conclusion