Current status and future perspectives of Neotropical freshwater stingrays (Potamotrygoninae, Myliobatiformes) genetics

Potamotrygoninae is a group of stingrays fully adapted to South American freshwater ecosystems. Recently, there has been an increase in the number of publications applying genetic tools. The present review compiles and discusses the recent advances of these studies and the future perspectives for the genetic studies of this group. Mitochondrial markers are the main molecular marker applied, especially cytochrome c oxidase I and cytochrome b. The genetic studies were grouped in thematic areas, and the advances and challenges of each topic comprising evolution, taxonomy, phylogeography, hybridization, cytogenetics, and transcriptomes were discussed. Despite the recent efforts and increase in the number of studies in recent years, several questions for the group remain unanswered, mainly for Potamotrygon species, which present high genetic similarity despite their phenotypic plasticity. The application of genomics techniques might aid to elucidate the complex questions still open for freshwater stingrays.