Phylogeography of Oligosarcus acutirostris (Characiformes: Characidae): testing biogeographic hypotheses in the Northeastern Mata Atlântica freshwater ecoregion

Abstract The Northeastern Mata Atlântica freshwater ecoregion (NMAF) is recognized for the high degree of endemism its ichthyofauna, whose evolutionary and biogeographic histories are still poorly understood. Oligosarcus acutirostris a fish species endemic to NMAF, which distributed in coastal rivers streams draining Bahia, Espírito Santo, part Minas Gerais states eastern Brazil. Its widespread distribution currently isolated river basins along NMAF prompted this study, aimed understand what scenarios would be involved determining current pattern, contribute better understanding history NMAF. For this, mitochondrial nuclear DNA sequences were analyzed based on samples from different localities distribution, including type locality. Overall, phylogeographic analyses indicate strong genetic structure within evidenced mainly by non-sharing haplotypes between most analyzed. According AMOVA results, explained Pleistocene paleodrainages. results also used test complement hypothesis previously proposed drainages