DISSERTATION RESEARCH: Remnants of a Diverse Past: Assessing the Phylogenetic position of recently extinct Pleurocerid snails (Gastropoda: Pleuroceridae)

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Freshwater snails of the family Pleuroceridae are of high conservation priority, but little is known about their biology. The objective of this project is to infer the evolutionary relationships of Leptoxis (11 extant and 13 extinct species) and the recently extinct Gyrotoma (6 extinct species) in order to aid in defining biologically-relevant conservation units. Mitochondrial and nuclear DNA sequences of extant and recently extinct Leptoxis and Gyrotoma will be used to infer their evolutionary relationships. Dried tissue from shells that were deposited in natural history collections will be used to obtain DNA of extinct species. Inclusion of extinct species, in addition to extant species, will increase the robustness of evolutionary hypotheses resulting from this study. This will be the first evolutionary study that includes all Leptoxis and Gyrotoma species.Aquatic ecosystems are essential to the health of society, but these systems are subject to high levels of anthropogenic stress. The health of water resources in the southeastern U.S. depends on the continued survival of pleurocerid snails which are cornerstone species in these systems. The genus Leptoxis presents special conservation concerns as 13 Leptoxis species have gone extinct in the last 50 years. This project will ultimately increase the effectiveness of conservation plans for Leptoxis by aiding in the definition of management units.