Distribution of Fishes in the Red River of the North Basin on Multivariate Environmental Gradients
Cyprinidae
Pearl Dace
Margariscus margarita Cope, the pearl dace, was listed as Leuciscus
nachtriebi by Cox (1897), who examined several specimens collected by F.B.
Sumner, University of Minnesota, from Elbow Lake (Otter Tail River) (Figure A24).
Olson (1932) reported M. m. nachtriebi, collecting 14 individuals from the south
branch of the Wild Rice River north of Ulen, Minnesota; and in 1955, the species
was reported from Shotley Brook (Red Lake River) (BMNH 1994). The pearl dace
has since been collected only occasionally in the Red River basin and has never
been found again in the reaches of these early reports. The species has been
most abundant in the Park River, where as many as 80 individuals have been
reported at a single site; the Mud and Moose Rivers (Thief/Red Lake River),
where as many as 124 individuals have been reported at a single site; and the
Snake, Middle, and Tamarac Rivers, where as many as 40 individuals have been
reported at a single site. The pearl dace has preferred reaches within the NMW
ecoregion, where it has been found at 19% of sites sampled (Table 4).
Figure A24. Distribution of the pearl dace in streams of the Red River of the North basin.