Phylogenetic Status and Divergence of Florida's Southern Tessellated Darter

The Florida population of Southern Tessellated Darter (Etheostoma olmstedi maculaticeps) is isolated from the next closest known population in the Altamaha River Basin, Georgia, by more than 200 km.  We collected darter tissues from seven basins throughout its distribution, and analyzed the samples to determine the phylogenic status of the subspecies throughout its range, determine whether the Florida population is monophyletic, and characterize the level of genetic diversity within different basins.  Results inferred from cyt b sequences indicated that the Florida population was nested within a larger clade that included immediate geographic neighbors in Georgia Basins, but was monophyletic within the clade.  Based on molecular genetic dating, the Ocklawaha River basin population has been isolated from its closest drainage for an estimated 150,000 years.  The genetic diversity of darters collected from Florida was considerably lower compared to six other basins, providing additional support for a long-term isolation in Florida and suggesting that the population size has been small for a long period of time.  These results are important for managers responsible for protecting habitat in areas where this species is known to occur within Florida and who may consider translocation of individuals from other states to supplement the Florida population.