Exploring hidden diversity: Molecular insights into the Leporinus species of the rivers of the Brazilian states of Maranh?o and Piau

The present study delved into the world of hidden diversity by examining specimens identified as Leporinus piau from the river basins of the northern Brazilian states of Maranhao and Piaui. Using genetic analyses that combined data from three mitochondrial markers and one nuclear marker, the study identified two well-supported groups, reinforcing the findings of previous publications. The first group, found in samples from the Itapecuru, Mearim, Turiacu, and Pericuma basins, in Maranhao, appears to represent a relatively ancient diversification and the possibility of concealed cryptic diversity. The second group, comprising specimens from the Parnaiba (Piaui) and Mearim (Maranhao) basins, appears to have resulted from a more recent process of diversification and has a close relationship with Leporinus friderici from the type locality. Our findings not only confirm the existence of a complex scenario of cryptic diversity in the genus Leporinus from the study basins but also underscore the taxonomic inconsistencies within this group of fish. This study offers a comprehensive analysis of the species diversity of the Maranhao and Piaui basins, which are critical regions for the conservation of Amazonian fish, providing valuable insights for the sustainable management and conservation of these fish.