Phylogeny of the hyperdiverse order Characiformes (Teleostei: Ostariophysi) using ultraconserved elements

Abstract

The order Characiformes, one of the largest components of the freshwater fish fauna in the world, with over 2000 known species, is one of the least studied groups in the systematic point of view. Within this order is the Characidae family, one of the largest families of fish, with more than 1000 species. The species of this order always have great ecological and economic importance in the regions where they occur, where they are used directly for human consumption or in the aquarium hobby. In the Neotropical region, Characiformes represent about a third of all freshwater fish species. A recent study conducted by our research group, involving molecular data, presented a new hypothesis of relationships among Characiformes, proposing the recognition of five families, not previously used, and a new definition of Characidae. Although this study has provided a major advance in our knowledge of the systematics of Characiformes, there is still the need for further studies, especially in relation to many highly species rich groups of Characidae and to several families of Characiformes. A general review of the available literature revels that it is also clear that there is a need for the use of new, and more resolute, molecular markers since many of the relationships among families are still poorly resolved. In this sense we are proposing the construction of a new phylogeny, employing the more modem techniques of next-generation sequencing (phylogenomic) generate data about ultraconserved elements (UCEs), whose use in phylogenetic systematics has showing promising data. In this project, we are also proposing the enrichment of molecular data banks, such BOLD, to allow the molecular identification of all species to be analyzed in the present investigation. Thus, the present study will be fundamental for a better understanding of what groups belong to Characiformes and to test the hypotheses about the relations among families, the relationships among genera and species within families and the historical biogeography of the group who is now distributed in many basins of the Ethiopic and Neotropical regions. (AU)