Genetic structure between isolated populations of the federally endangered amber darter (Percina antesella)

Originally discovered in 1948, the amber darter (Percina antesella) was thought to have been extirpated just years later with the construction of Allatoona Dam on the Etowah River in 1950.  It received Federal protection as an endangered species in 1985, and was found to be persisting in portions of the Etowah and Conasauga Rivers in the 1990s.  We sequenced 2187 bp of mitochondrial DNA (cyt b and ND2 genes) from amber darters collected at multiple locations from each river and found very low levels of variation.  In addition to finding no phylogenetic structure between populations, some individuals from the Etowah and Consauga Rivers shared identical haplotypes.  In order to look for finer levels of genetic structure, we have developed and analyzed nuclear microsatellite markers.  These results have important implications for the management of fragmented populations of this endangered species.