Conservation genetics of an endemic mountaintop salamander with an extremely limited range

• Published in: Conservation genetics Vol. 13; no. 2; pp. 443 - 454
• Main Authors: Bayer, Claire S. O., Sackman, Andrew M., Bezold, Kelly, Cabe, Paul R., Marsh, David M.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.04.2012; Springer Nature B.V
• Subjects: allopatric speciation; Animal Genetics and Genomics; Biodiversity; Biodiversity hot spots; Biomedical and Life Sciences; Blue Ridge Mountain region; Caudata; Conservation biology; Conservation Biology/Ecology; Conservation genetics; Conservation status; Ecology; Evolutionary Biology; Fish; Genetics; introgression; Life Sciences; Mountain regions; Mountains; nucleotide sequences; phylogeny; Plant Genetics and Genomics; Plethodon; Plethodon cinereus; Plethodon serratus; Research Article; salamanders and newts; Speciation; Virginia; Virginia; Blue Ridge Mountain region; ANW, USA, Virginia; USA, Blue Ridge Mts; mtDNA; Population genetics; Phylogeography; Big Levels salamander
• ISSN: 1566-0621; 1572-9737
• DOI: 10.1007/s10592-011-0297-7

Montane regions can promote allopatric speciation and harbor unique species with small ranges. The southern Appalachians are a biodiversity hotspot for salamanders, and several montane endemics occur in the region. Here, we present the first DNA sequence data for Plethodon sherando , a terrestrial salamander recently discovered in the Blue Ridge Mountains of Virginia. We sequenced two mitochondrial regions (cyt-b and CO1) from salamanders at reference sites near the center of P. sherando ’s range and from two contact zones where P. sherando populations are replaced by Plethodon cinereus , the Northern Red-Backed salamander. We then used these sequence data to examine divergence and hybridization between the two taxa. We found P. sherando and P. cinereus morphotypes from contact zones to be reciprocally monophyletic and highly divergent (~17%). P. sherando exhibited very low sequence diversity (π = 0.0010) as compared to P. cinereus from the same locations (π = 0.0096). Salamander morphology in the contact zone was as distinct as morphology at reference sites, and discriminant function analysis based on morphology successfully classified 98% of salamanders to their mitochondrial lineage. Phylogenetic analysis of cyt-b sequences showed P. sherando to be sister to Plethodon serratus (the Southern Red-Backed salamander) rather than P. cinereus or any nearby mountaintop endemics. Our results suggest that P. sherando is a distinct lineage that is not subject to substantial introgression from P. cinereus and that may have a history of geographic isolation. Given its limited range (<80 km 2 ), we believe P. sherando should merit a conservation status similar to that of other mountaintop salamanders in the region.