Zoogeography of Ouachita Highland fishes

Abstract

Knowledge about species distributions in space and time is a central goal of comparative phylogeography, and essential to understanding evolution, ultimately providing the mechanisms for the origin and maintenance of biological diversity. The Ouachita Highlands of central North America, together with the Ozark and Eastern Highlands, comprised a once continuous upland region now separated by intervening lowland habitats unsuitable for most highland species. These disjunct upland habitats now support exceptional richness in aquatic taxa. The complex biogeographic history of the Ouachita Highlands provides an excellent opportunity to investigate taxa with distinctive distributional patterns. In this dissertation I use mtDNA and microsatellite variation to assess the phylogeographic history, demographic changes and conservation status of small-bodied fishes of the Ouachita Highlands. The first study examines phylogeographic history of Notropis suttkusi (rocky shiner) to infer historical factors governing the composition of the fish assemblage. My second study investigates the impacts of reservoirs on the genetic structure of Percina pantherina (leopard darter), a federally threatened species of the Little River system. My third study examines how intrinsic life-history attributes mediate patterns of genetic variation and gene flow in two syntopic darters, P. pantherina and P. caprodes (logperch). Last, my final two chapters are methodological notes describing the development of microsatellite markers used to conduct the above investigations.