Data from: Species limits and introgression in Pimelodus from the Magdalena-Cauca River basin

<p>Low morphological differentiation among taxa hampers its appropriate identification, basic biological studies, and promotion of any conservation effort. Aiming to clarify the evolution and speciation among members of <i>Pimelodus </i>from the Magdalena-Cauca River basin, this study tested the hypothesis that <i>P. yuma, P. grosskopfii </i>and<i> P. crypticus</i> represent<i> </i>three independently evolving species and explored signals of interspecific hybridization. Likewise, we test the ancient hypothesis that the <i>trans</i>-Andean <i>Pimelodus yuma</i> and <i>P. crypticus</i> belong to the <i>cis</i>-Andean <i>P. blochii </i>species complex. The outcomes based on mitochondrial (<i>cox1</i>) and nuclear [RADseq (Illumina Hi-Seq), microsatellites and <i>rag2</i>] markers combined with coalescence-based and allele-frequency methods, confirm that each studied <i>trans</i>-Andean species represent<i> </i>an independently evolving unit. We used Stacks v.2.52 for <i>de novo</i> SNP genotyping. Contrary to expectations, <i>P. yuma </i>was<i> </i>found as a sister clade of <i>P. blochii</i>, while <i>P. crypticus </i>(confused for a long time with <i>P. blochii</i>) was phylogenetic closer to <i>P. grosskopfii</i>. Additionally, we found strong evidence of historical introgression between the non-sibling species <i>Pimelodus yuma </i>and<i> P. grosskopfii, </i>breaking the absence of interbreeding and the independent evolutionary trajectory among Trans-Andean <i>Pimelodus </i>during their diversification history, a pre-requisite to define species limits. However, non-significant values of current gene flow were evidenced between them, supporting the hypothesis of full isolation.</p>