Contemporary evolution of neutral genetic structure in introduced Klamath smallscale suckers (Catostomus rimiculus) recapitulates native patterns

Abstract

We investigated the riverscape genetic structure of Klamath smallscale suckers (Catostomus rimiculus) in the Smith River, California, a population believed to have been introduced and founded by approximately six individuals within the last 100 years. Analyzing 15 microsatellites from larval samples across the species’ entire known Smith River range, we discerned: (1) increased genetic diversity downstream, (2) increased within-site differentiation upstream, and (3) isolation by river distance. These introduced suckers displayed a genetic profile expected for native species in river networks, indicating post-introduction contemporary evolution of neutral genetic structure unconstrained by a small founding population size. Application of available models of processes generating genetic variation in river networks suggested that upstream colonization generated the patterns we observed. The Smith River population of Klamath smallscale suckers may be in genetic equilibrium or may be continuing to expand since a likely introduction between the 1890s and 1970s.

Citation

Kinziger, Andrew P.; Fong, Steven R.; Nakamoto, Rodney J.; White, Jason L.; Harvey, Bret C. 2024. Contemporary evolution of neutral genetic structure in introduced Klamath smallscale suckers (Catostomus rimiculus) recapitulates native patterns. Conservation Genetics. 90(7): 612. https://doi.org/10.1007/s10592-024-01651-5.