Conservation genomic assessment of imperiled freshwater fishes endemic to the Pecos and Devils Rivers

Many freshwater fishes endemic to spring-fed tributaries of the lower Rio Grande within Texas exhibit small, highly fragmented distributions and are a priority for conservation. The five target species (Dionda diaboli, D. argentosa, Cyprinella proserpina, Etheostoma grahami, and Notropis megalops) in this study have distributions that lie almost entirely within two native fish conservation areas, deemed important for maintaining the state’s native fish diversity. Previous research reported low levels of haplotype and microsatellite diversity of D. diaboli and D. argentosa as well as a sympatric species of Notropis. Due to the extreme vulnerability of these species, assessing levels of standing genetic diversity at the genome level is essential for conservation. Each target species will be collected across multiple sites in the Pecos and/or Devils Rivers. Double digest restriction-site associated DNA (ddRAD) sequencing will be used to characterize single nucleotide polymorphisms (SNPs) for each species across the genome, and patterns of genetic variation within and among sampling localities will be assessed. Additional museum samples (>30 for each species) will be used to facilitate comparisons of contemporary diversity with that of the recent past. This project will provide information on standing genetic diversity (neutral and putatively adaptive) and connectivity among sampling localities within species, allowing managers to prioritize actions on areas harboring vulnerable populations.