Genome sequencing of three Orestias species and the analysis of their phylogenetic relationships within the Cyprinodontiformes order

We reconstructed an upgraded phylogeny of the order Cyprinodontiformes using both, available genomic and genetic information. Furthermore, we inferred the position of Orestias, a pupfish genus from the Andean Altiplano.For this sake, we selected representatives of each genus within the order and, using 12 molecular markers, we estimated their phylogenetic relationships and divergence times. Additionally, the genome sequences of three Orestias species (our data) were sequenced, assembled and explored in terms of genome size and content of transposable elements. Finally, using the publicly available genome assemblies of other Cyprinodontiformes, we generated a phylogenomic tree considering 902 single-copy orthologs to establish the systematic position of Orestias.Our results clearly indicate that Orestias is not part of the Cyprinodontidae family. Rather, it belongs to the re-discovered Orestiidae family, constituted by the Orestias and, possibly, the Pseudorestias genera. This supports that Orestiidae is more closely related to other South American families, and it has been isolated in the Altiplano since the Eocene-Oligocene transition.