Molecular phylogeography of Characodon (Goodeidae) from the Mexican high plateau

" Characodon lateralis and C. audax are livebearing, freshwater fishes of the family Goodeid ae. Their distribution, disjunct from all other members of the Goodeinae, is limited to the upper Rio Mezquital and its adjacent springs on the Mexican high plateau. This study will reconstruct a molecular phylogeny of the genus and assess current taxonomy. Approximately 420 bases of the mitochondrial control region was amplified and sequenced for at least two individuals from seven localities (six C. lateralis and one C. audax) distributed across the range of Characodon. Sequences of these individuals and six outgroups (three goodeines, two empetrichthyines, and Profundulus) were aligned and phylogenetic relationships inferred. Gene genealogies were also reconstructed using statistical parsimony. Characodon was recovered as monophyletic, and strong support was found for two clades. However, this locus was not found to support the two species as now recognized. C. audax was strongly supported within a clade that includes four of the six C. lateralis localities, thereby rendering C. lateralis paraphyletic. If this locus reflects the evolutionary history of Characodon, then the nomenclature may need reevaluation. Additionally, greater genetic diversity was found in the clade occurring below the waterfalls on the Rio Mezquital. Biogeographic implications and the timing of diversification within the genus will be discussed "