Population Genetics of Spotted Salamanders (Ambystoma maculatum)

Abstract:

Urbanization – although important for humans’ can lead to habitat fragmentation, which impacts the organisms living in these ecosystems. One local example of fragmentation is the Bayfront Connector in Erie, PA. This highway was constructed in 2005 to facilitate transportation into the city, but it divided a natural wetland that is home to many sensitive species. The spotted salamander (Ambystoma maculatum) is one species that relies on this wetland habitat. It is possible that the fragmented salamander sub-populations have been impacted by the expressway, given that reproductive isolation can contribute to an overall decline in genetic diversity. The purpose of this study was to evaluate the genetic diversity of the spotted salamander sub-populations within the Penn State Behrend campus. In 2020, tissue samples (toe clips) were taken from ~30 salamanders in each sub-population (115 total). Four polymorphic microsatellite loci were amplified by multiplex PCR and sized via fragment analysis; these data were used to genotype the individual salamanders. Estimates of genetic diversity (allelic richness, heterozygosity) and population differentiation (F_ST) were calculated for each locus and each sub-population. Case studies concerning abundant species’ such as spotted salamanders’ provide valuable information that may inform conservation efforts aimed toward more sensitive amphibian species that are similarly threatened by urbanization.