https://link.springer.com/article/10.10 ... 24-05731-y
Abstract was described using the morphology of specimens from tributaries of the Rio Uruguay (Upper Uruguay ecoregion) and one paratype from the Rio Tibagi (Upper Paraná ecoregion). Recent sampling near the Ponta Grossa Arch, a key uplift that changed the fluvial dynamics in southern Brazil, revealed the presence of additional specimens in the Upper Parana ecoregion and also in the Ribeira de Iguape ecoregion. Through these samples (including sample tissues), we tested if the populations of the Upper Uruguay, Upper Paraná, and Ribeira de Iguape ecoregions constituted different species and if the phylogeographic pattern was impacted by recent geomorphological events that allowed headwater captures. Using COI, we delimited C. perkos “sensu stricto” from a putative new species of Cambeva, estimating their divergence around 14.5 Mya, likely due to ancient erosion events in Serra do Repartimento and Serra Geral. Furthermore, the two species are not closely related according to the COI arrangement. In addition, we recognized three morphotypes belonging to the putative new species, which did not show a unique signature of differentiation through COI. Lastly, we hypothesized that recent erosions (2.2 Mya) in the Ponta Grossa Arch influenced the geographic distribution of the new species.
