Perspectivas sobre a biologia evolutiva de Psalidodon fasciatus (Teleostei: Characiformes), com foco no Parque Estadual de Vila Velha Paraná, Brasil

Abstract

Isolated karstic environments, such as sinkholes, provide ideal natural settings to investigate the ecological and evolutionary consequences of isolation on freshwater fish biodiversity. In this thesis, we examined the ichthyofauna of these formations in Vila Velha State Park (VVSP), southern Brazil, with a particular focus on Psalidodon fasciatus, using an integrated approach that combines environmental DNA, genomics, and cytogenetics. eDNA metabarcoding revealed low taxonomic diversity within sinkholes compared to riverine habitats of the Tibagi River Basin, underscoring the ecological isolation of these systems. Genomic analyses based on SNPs and mitochondrial genomes uncovered strong genetic structure and long-term divergence in the sinkhole population, with no evidence of gene flow and divergence beginning in the Pleistocene. Cytogenetic mapping of repetitive elements and satellite DNAs further revealed distinct chromosomal patterns between isolated and connected populations. Collectively, these findings highlight the role of karst systems in shaping genetically distinct lineages and contribute to our understanding of diversification mechanisms in Neotropical subterranean environments.