Molecular ecology of mountain sucker in Western North America

Authors: Marlis R. Douglas, Michael E. Douglas

Year: 2012 (xliv)

Abstract

A combination of 2 mitochondrial (mt) DNA genes and 16 microsatellite DNA loci were employed to define distinct evolutionary lineages (ESUs) and demographically independent populations (MUs) in 847 Mountain Sucker [Catostomus (Pantosteus) platyrhynchus] across 57 sites (Colorado River Basin = 51; Bonneville Basin = 5; Columbia River Basin = 1; Missouri River Basin = 1). ESUs (N=4) were distributed primarily by basin (i.e., Missouri, Bonneville/ Snake, Colorado, River, and Price River within the Colorado River drainage). Haplotypes from the Price River may well represent a residual from ancient Lake Bonneville as they clustered with Missouri and Bonneville/ Snake basin haplotypes. Individuals were also assigned to 12 distinct adrainage-specific clades based upon multi-locus msat genotypes. However, only 9 of these qualified as demographically independent MUs in subsequent analyses (i.e., migrants/ generation <10%). Drainage specificity in Mountain Sucker is not surprising, particularly given its propensity to populate smaller streams at greater elevations, and suggests the potential for elevated endemism in this species, much more than in Bluehead Sucker. Mountain Sucker will become considerably more restricted in its distribution as its habitat fragments, and thus vulnerable to additional anthropogenic threats as temperatures elevate and waters warm.