Date of Award


Document Type


Degree Name

Master of Science (MS) in Biology




"The purpose of this study was to determine the distribution of New Zealand mud snails (Potamopyrgus antipodarum) in the lower Snake River and three tributaries and to determine if this invasive snail is competing with native gastropods. Potamopyrgus antipodarum is a successful invader in much of the Western United States and has been shown to impact nutrient cycling and community structure in invaded ecosystems. This study is divided into two chapters: the first chapter focuses on the current density and genera richness of native gastropods and the distribution of P. antipodarum in the Lower Snake River and three tributaries near Lewiston, Idaho; while the second chapter explores the possibility that P. antipodarum may be competing for food resources with the native pebble snail, Fluminicola. The field survey of native gastropods serves the dual purpose of determining the level of invasion of P. antipodarum in the Lower Snake River and surrounding tributaries as well as providing a baseline survey of native gastropod density and genus richness. Limited studies of the pre-invasion distribution and abundance of native gastropods exist making this baseline survey an important study which may provide insights into how native gastropod populations change as levels of P. antipodarum increase. Conflicting results from competition experiments between native gastropods and P. antipodarum has resulted in an ambiguous understanding of the impacts P. antipodarum may be having on native gastropods. The second chapter of this study looks at the grazing rates of Fluminicola under intra- and inter-specific competition to aid in the understanding of how P. antipodarum may be impacting native gastropods"--Document.


Typescript. Vita.

Included in

Biology Commons