Phylogeography of the Slimy Salamander Complex (Plethodon: Plethodontidae) in Alabama

The Plethodon glutinosus complex is composed of 16 lineages that are thought to have conserved morphological characteristics and rapid rates of diversification. Typically, these lineages are recognized as species, but the monophyly of some has been questioned. Three lineages have distributions that converge in the state of Alabama: Plethodon glutinosus, P. grobmani, and P. Mississippi. If these species are present in the state and are reproductively isolated, then we expected to recover three monophyletic lineages. If these species are present in the state, but exhibit extensive introgression, then we expected to recover sets of private haplotypes associated with each species and sets of shared haplotypes among species. We sampled 40 specimens of slimy salamanders from throughout the state. Samples were analyzed using two genes, cytochrome b (n = 38) and RPL12 (n = 17). Additionally, we added 47 cytochrome b sequences for Alabama specimens of the three species available on GenBank to examine relationships of this larger sample. We failed to recover three monophyletic lineages within any estimated gene tree and failed to recover sets of private haplotypes. Instead, haplotype-network structure revealed a single metapopulation. We conclude that Alabama contains a single species of slimy salamander, Plethodon glutinosus, with complex genetic connectivity throughout the state