Moxostoma macrolepidotum

Moxostoma breviceps and M. pisolabrum formerly were included as subspecies of M. macrolepidotum but were listed as distinct species by Nelson et al. (2004), following Harris et al. (2002) and advice of R. E. Jenkins.

Harris and Mayden (2001) used molecular data to examine phylogenetic relationships of major clades of Catostomidae. In all trees, Scartomyzon was paraphyletic and embedded in Moxostoma, and Catosotmus was never recovered as monophyletic (Xyrauchen was embedded within Catosotmus). They concluded that the phylogenetic relationships and taxonomic composition of taxa presently included in Moxostoma and Scartomyzon are in need of further study, as are the relationships and composition of the genera Catosotmus, Chasmistes, Deltistes, and Xyrauchen, and the phylogenetic affinites of Erimyzon and Minytrema.

See Smith (1992) for a study of the phylogeny and biogeography of the Catostomidae.

Mississippi and Missouri river basins, Great Lakes-St. Lawrence River basin, many drainages of southwestern Hudson Bay basin, and Atlantic slope from the Santee drainage north to Hudson drainage (Lee et al. 1980), from Quebec to Alberta, south to Wyoming, Oklahoma, northern Missouri, Illinois, northern Ohio, and New York, and along the east coast south to South Carolina. Ozark and Ohio River basin populations are now regarded as distinct species, M. pisolabrum and M. breviceps (Nelson et al. 2004).

This species is represented by a large number of subpopulations and locations.

Localized threats may exist, but on a range-wide scale no major threats are known.