The Hidden Hitchhiker


The Hidden Hitchhiker


Semi-finalist in the Graduate Image of Research Contest 2016.


I have been exploring the reproductive health of Illinois River fishes. The river begins below Chicago where it connects to the Chicago Sanitary and Ship Canal and flows into the Mississippi. Based on long-term data, it appears that some sportfish may be facing population declines, particularly in the upper part of the river. This may or may not be coincidental of the fact that there could be higher pollution loads the closer one gets to the
urbanization. Although there are wastewater treatment facilities in place, many detrimental chemicals pass into our rivers and affect fish that are particularly susceptible due to their intake of water through the gills. My research focuses on chemicals that wreak havoc on the reproduction of fishes by acting as synthetic hormones or toxic compounds, eventually taxing their bodies enough to decrease their overall health. I examined this slide of male fish reproductive organs in order to observe potential hermaphroditism induced by said chemicals, when I discovered parasitic infections. This could indicate that the defenses in fish are being compromised by poor water quality and such infections in fish could become
decreased reproductive health in our fish populations.


Madeleine VanMiddlesworth




Copyright 2016 Madeleine VanMiddlesworth


Natural Resources and Environmental Sciences

Original Format





Madeleine VanMiddlesworth, “The Hidden Hitchhiker,” Image of Research: Celebrating Student Research at Illinois, accessed December 10, 2018,