Integrative taxonomy: Morphology and ancient DNA barcoding reveals the true identity of Astyanax teniatus, a tetra collected by Charles Darwin during the Beagle's Voyage

In this study, in order to retrieve taxonomic data and to warrant an accurate identification for A. taeniatus henceforth, we integrated molecular and morphology data obtained from syntypes and new specimens collected in the type-locality. Additionally, information from Darwin's journal and from a Brazilian project to retrieve Darwin's travels in Brazil ("Caminhos de Darwin"), allowed to accurately locate the A. taeniatus type-locality at Conceição de Macabú municipality, northern Rio de Janeiro State. The two syntypes of Tetragonopterus taeniatus were examined and a tissue sample was extracted from one of them to compare genetically to other Astyanax species. Then, the Cytochrome Oxidase Subunit I (COI) sequence of this syntype was included in a matrix with 27 characid species from Brazilian coastal rivers, including those collected in the Córrego das Aduelas at type-locality. The smallest values of p-distance (0.01) were found between the sequences of the syntype and specimens of Astyanax from Córrego das Aduelas, Rio Macaé basin, in “Fazenda Socego”. The anatomical and meristic information of the modern specimens collected in the type-locality also agree with data from the syntypes. Integrating morphology and molecular techniques for ancient DNA, we succeeded to definitely solve the taxonomy of A. taeniatus and also identify modern topotypes in Córrego das Aduelas at Conceição de Macabu (RJ). Based on the syntypes and on a collection of Astyanax taeniatus, incl...
Source: A Journal of Comparative Zoology - Category: Zoology Source Type: research