Data from: Molecular phylogenetics and microsatellite analysis reveals cryptic species of speckled dace (Cyprinidae: Rhinichthys osculus) in Oregon’s Great Basin

Speckled dace (Rhinichthys osculus) is a small cyprinid that occurs
throughout western North America and is the most commonly occurring fish
in Oregon. Because of the high genetic and morphological variation in this
species across its range, it has been referred to as a species complex;
however, no revision to its taxonomy has occurred since 1984. Here, the
phylogenetics and population genetics of speckled dace are examined
throughout Oregon’s Great Basin to describe genetic variation and infer
the geographic boundaries between distinct taxonomic entities and
populations. We tested the validity of a putative subspecies, Foskett
Spring speckled dace, that occurs in a single spring within Warner Valley
in Southeast Oregon and is listed Federally as threatened. Dace were
collected from Foskett Spring and all surrounding basins containing
speckled dace (Warner, Goose Lake, Lake Abert, Silver Lake, and Malheur),
as well as Stinking Lake Spring (located within Malheur), created
phylogenetic trees from mitochondrial ND2 and nuclear S7 sequence data,
and genotyped eight microsatellite loci for population-level analyses.
Three highly divergent clades warrant species-level status: Malheur stream
dace, Stinking Lake Spring dace, and dace from the other four basins
combined. Although Foskett Spring dace were not monophyletic, substantial
population structure occurs at the basin-level and separates Foskett
Spring dace from other dace in the surrounding Warner Valley. Thus, we
recommend ESU status for the isolated population of speckled dace in
Foskett Spring. The high, previously unrecognized, taxonomic diversity
within this region indicates a need for a range-wide phylogeographic study
of speckled dace and an investigation of the morphological distinctiveness
of the putative new species.