Data from: Genetic structure and diversity of the blueface darter Etheostoma cyanoprosopum, a microendemic freshwater fish in the southeastern United States

Darters represent one of the most diverse groups of freshwater fishes in
North America, but approximately 33% of the 215 recognized species are
considered imperiled on the IUCN Red List. Discovery and description of
new darter species continues at a relatively rapid pace, with many
exhibiting microendemic geographic distributions and little baseline data
for conservation decisions. The Blueface Darter Etheostoma cyanoprosopum
is a newly described species that occupies < 20 km of stream
reaches in the Bear Creek system of the Tennessee River drainage and the
Hubbard Creek system of the Black Warrior River drainage in the Mobile
Basin (Alabama, USA). In addition to restricted distribution, the species
is threatened by habitat degradation and several natural and man-made
barriers that putatively fragment connectivity among populations. This
study used microsatellite and mitochondrial (mt) DNA data with comparisons
to the relatively broadly distributed sister species (Bandfin Darter E.
zonistium) to evaluate multiple objectives about genetic connectivity and
diversity among Blueface Darter populations. Analysis of mtDNA data
indicated a lack of historical structuring across the Tennessee-Black
Warrior river drainage divide and within the Bear Creek system. However,
microsatellite-based Bayesian cluster analyses and F-statistics suggested
contemporary isolation across the drainage divide and evidence for
reservoir-induced fragmentation within the Bear Creek system. Compared to
the sister Bandfin Darter, Blueface Darter populations exhibited reduced
levels of genetic diversity, rendering them more susceptible to local
extirpation and reduced fitness. Continued monitoring and quantitative
ecological studies are recommended to understand population-specific
measures of occurrence and abundance.