Publication Date


Document Type


First Advisor

Koop, Jennifer A.

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Biological Sciences


Invasive species pose a major threat to biodiversity and are becoming increasingly common across the globe. The success of these invasive species often comes down to an ability to disperse effectively into novel environments over time and at multiple scales. Aquatic invasive species can be particularly challenging as they are not readily visible and are often well established before being formally observed. In the Upper Mississippi River region, an invasive European snail species, the faucet snail (Bithynia tentaculata) has invaded from Europe via the Great Lakes. The snail serves as an intermediate host for several species of trematode parasites that have been implicated in causing large-scale waterfowl die-offs in the region. It is unclear currently whether the trematodes co-invaded with the faucet snails or if they are a product of spillback (i.e., invasive species serving as alternative hosts for native parasites). Here, we analyzed faucet snail movement both a small-scale and large-scale range. For small-scale dispersal analysis, we created a framework for undergraduate-level, student-driven experiments addressing abiotic and biotic factors’ affect on faucet snail movement within their immediate surroundings. This framework offers opportunity for continued research on small-scale dispersal as well as promoting students’ applied skills and continued engagement in the field of science. For large-scale dispersal analysis, we used genomic sequencing and population analyses to estimate the overall population structure and likely invasion pathway for the faucet snail. Adult snails were collected from Europe (native range), the Erie Canal (assumed early point of introduction) and several points along the Mississippi River (current invasion forefront). Population genomic analyses indicate a large degree of differentiation between snails in the native and invasive ranges. There was a lesser degree of differentiation between Erie canal and Mississippi river populations, and almost no genetic differentiation between populations within the Mississippi river. These analyses show that gene flow is the highest among populations at the current invasion forefront indicating that populations are not moving or becoming separated after movement due to individual external factors rather that they are able to consistently move amongst themselves as they spread down the Mississippi River. This study lays the groundwork in assessing the invasion history of the faucet snail so that a similar genetic analysis of the movement of the trematodes can be used to create a parallel invasion history for the two groups to assess the likelihood of co-invasion.


65 pages




Northern Illinois University

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