https://link.springer.com/article/10.10 ... 24-01659-x
Keywords: Freshwater neotropical fish, Genotyping-by-sequencing - GBS, Mitochondrial DNA, Phylogenetics, Pimelodidae, TaxonomyAbstract , the most diverse genus of Pimelodidae, has a complex taxonomic history. Various species occur in the Paraná River Basin of South America, with some, including P. maculatus and P. platicirris, in sympatry. is widely distributed in this watershed, whereas P. platicirris is poorly known and cited for only a few locations in the Upper Paraná River Basin. The taxonomic status of P. platicirris has been the subject of discussion due to insufficient diagnosis and the sharing of apomorphic characters with other species. We tested for morphometric and genetic differentiation between non-topotype fishes identified as P. maculatus and P. platicirris based on color pattern. We sampled 16 individuals of each species in the Araguari River, Upper Paraná River Basin, and analyzed them for 29 morphometrical characters, DNA barcoding and 13,581 nuclear SNPs. Morphometrical analysis indicated no differences between the two species. Similarly, mitochondrial DNA analysis, which included sequences of topotype individuals of P. maculatus available online, supported all P. platicirris individuals as belonging to the P. maculatus lineage from the Upper and Lower Paraná River basins, without nuclear genetic differentiation. These results indicate that the non-topotype individuals dentified as P. platicirris based on color pattern are indeed P. maculatus. Consequently, the diagnostic characters usually attributed to delimiting P. platicirris are instead part of the wide morphological and color pattern variation of P. maculatus. The taxonomy of P. platicirris merits special attention due to the possibility of synonymy with P. maculatus. Enhancing the understanding of Pimelodus biodiversity in the Paraná River Basin is key for the development of conservation programs specifically designed for its species.
