Cryptic diversity identified by DNA barcoding reveals the impact of pleistocene climate oscillations on a forest...

Quaternary climate oscillations significantly influenced the configuration of the Brazilian Atlantic Forest. In this study, mitochondrial DNA analysis of Enoploctenus cyclothorax (Bertkau, 1880) was conducted to investigate potential cryptic diversity within populations across the state of Paraná, Brazil. Two divergent genetic lineages were identified based on genetic distances, haplotype network, and phylogenetic inference. A phylogeographical break separates the lineages into two geographic regions; one lineage is found exclusively in the eastern region and the other is found mainly in the northern and western regions of the state. The coalescence tree estimates the divergence time between 1.8 million years and 500 000 years ago, period marked by glaciation, suggesting historical forest fragmentation as a potential isolating mechanism. These findings support the hypothesis of independently evolving units within E. cyclothorax, possibly representing cryptic species, though broader sampling and integrative approaches are necessary for taxonomic validation.