DNA barcoding reveals species level divergence between populations of the microhylid frog genus Arcovomer (Anura: Microhylidae) in the Atlantic Rainforest of southeastern Brazil

AbstractThe microhylid frogs belonging to the genus Arcovomer have been reported from lowland Atlantic Rainforest in the Brazilian states of Espirito Santo, Rio de Janeiro, and Sao Paulo. Here, we use DNA barcoding to assess levels of genetic divergence between apparently isolated populations in Espirito Santo and Rio de Janeiro. Our mtDNA data consisting of cytochrome oxidase subunit I (COI) nucleotide sequences reveals 13.2% uncorrected and 30.4% TIM2 + I + Γ corrected genetic divergences between these two populations. This level of divergence exceeds the suggested 10% uncorrected divergence threshold for elevating amphibian populations to candidate species using this marker, which implies that the Espirito Santo population is a species distinct from Arcovomer passarellii. Calibration of our model-corrected sequence divergence estimates suggests that the time of population divergence falls between 12 and 29 million years ago.