Conservation genomics of the threatened Trispot Darter (Etheostoma trisella)

The southeastern United States is a hotspot of biodiversity, but aquatic habitats are fragmented by anthropogenic activities such as hydrologic alteration. Small-stream-inhabiting fish can suffer population declines, loss of genetic diversity, and migration impediment from riverine impoundment. The Trispot Darter (Etheostoma trisella) is a small, freshwater fish endemic to the southeastern United States. E. trisella was previously believed to be extinct and has now been listed as threatened under the U.S. Endangered Species Act, due to destruction of its limited habitat and a restricted range. We used mitochondrial DNA (NADH dehydrogenase subunit 2 gene), seven microsatellite loci, and 9732 single nucleotide polymorphisms (SNPs) to evaluate population structure and diversity in E. trisella. Mitochondrial data provided evidence of historical connectivity between populations, with haplotype sharing across populations and weak support for population structure. Microsatellite and SNP data, ...