Smallmouth Bass Micropterus dolomieu Lacepède, 1802
Shannon K. Brewer and Donald J. Orth
The Smallmouth Bass Micropterus dolomieu was described by the French naturalist, Bernard Germaine de Lacepède in 1802 (type locality unknown), and two subspecies, Northern Smallmouth Bass M. d. dolomieu and Neosho Smallmouth Bass M. d. velox, were recognized by Hubbs and Bailey (1940). Near et al. (2005) consider Spotted Bass M. punctulatus and Smallmouth Bass to be a sister pair basal to all other Micropterus spp., based on mitochondrial and nuclear gene DNA. Three distinct evolutionary lineages are evident in the Ozark and Ouachita uplands (Stark and Echelle 1998).
The Smallmouth Bass is native to portions of the Ohio, Tennessee, upper Mississippi, and Saint Lawrence-Great Lakes systems of central and eastern North America (Scott and Crossman 1973). Spawning, migration, as well as historical events, including vicariance and climate change, influence the native distribution (Stepien et al. 2007). The northern form, M. d. dolomieu, is the more widespread subspeciesand occurs northeast of the Missouri and Meramec rivers, Missouri. The northern form intergrades with the Neosho subspecies, M. d. velox, in the Ozark highlands, and the Neosho subspecies is endemic to the extreme southwest Ozark streams of the Arkansas River basin (Hubbs and Bailey 1940; Stark and Echelle 1998). A genetically distinct population, without current formal taxonomic assignment, occupies streams of the Ouachita Mountains in Oklahoma and Arkansas at the extreme southwestern extent of the native range (MacCrimmon and Robbins 1974; Stark and Echelle 1998). Dispersal through drainage networks has resulted in some natural range expansion (Robbins and MacCrimmon 1974; Borden and Krebs 2009). Anticipated changes in thermal regime via climate change may facilitate northward expansion (Sharma and Jackson 2008); however, regions at the southern extent of the range lacking sufficient groundwater contributions may experience range contractions or population declines (Brewer et al. 2007; Brewer 2013b).