Paul Hime: Genome-scale resolution of species boundaries and demographyin Cryptobranchus

Hellbenders (genus Cryptobranchus) are large, obligately aquatic salamanders that are at risk of local extirpation and global extinction across their range in the eastern and central US. The past decade has seen the mobilization of substantial and multifarious conservation initiatives with hellbenders and many great strides have been made toward conserving these salamanders across their range including successful methods for captive propagation, non-invasive environmental detection methods using eDNA assays, and the recent federal listing of Ozark populations by USFWS. Despite these encouraging developments, effective and timely hellbender conservation still hinges critically upon understanding: 1) the boundaries between evolutionarily distinct lineages and the extent of cryptic species within this genus, 2) population-level parameters, such as effective population sizes, levels of genetic diversity, and rates of gene flow between populations, and 3) the extent of adaptive genetic divergence between different hellbender lineages. Emerging research suggests that Cryptobranchus may comprise several unrecognized cryptic species, each more imperiled than currently realized. Yet, existing population genetic and phylogenetic methods and current protocols for genetic data generation are unable to provide much needed genome-wide perspectives on lineage boundaries and population dynamics in this group, impeding comprehensive protection and repatriation efforts. Accordingly, our proposed research leverages several innovative genomic and analytical approaches to confront these pressing challenges. We have developed and will apply next-generation sequencing methods for genome analysis and multilocus species delimitation to reveal species boundaries and population genetic structure in this genus, setting the stage for genetically-informed conservation efforts in this declining group of salamanders.