Molecular Phylogeny Inferred from the Concatenated Genes of Two Neotropical Catfish Species and Implications for Conservation

The Neotropics host the most diverse ichthyofauna in the world, with catfish species forming one of the most diverse groups in the region. Nuclear (RAG1) and mitochondrial (ATPase and Cytb) markers were analyzed to identify genetic variability in populations of Pseudoplatystomareticulatum and Pseudoplatystomacorruscans from the La Plata and Sao Francisco Basins. Bayesian topology identified the division of P. corruscansinto two main clades. One of these clades was formed of samples from the Sao Francisco Basin and the other was formed of samples from the Parana+Paraguay Basins. P. reticulatum was grouped together without any clear geographic or taxonomic patterns in Bayesian topology. While only a few common nuclear haplotypes were widely identified in both species, there was great variability in the mitochondrial sequences. The genetic and geographical distance correlations were tested using the Mantel permutation, which detected no significant relationships.The results of the present study suggest a panmitic population for both species (excluding P. corruscansin the Sao Francisco Basin, which is suggested as a new species), with the greatest diversity concentrated in the region covered by the Pantanal biome, and the lowest diversity in Mogi Guacu, in the Parana Basin. These findings support the establishment of public conservation policies and provide information regarding genetic diversity and population differentiation patterns for these ecological and economically important species.