Theses and Dissertations

Issuing Body

Mississippi State University


Brooks, Christopher P.

Committee Member

Dibble, Eric D.

Committee Member

Ervin, Gary N.

Date of Degree


Document Type

Graduate Thesis - Open Access


Biological Sciences

Degree Name

Master of Science


College of Arts and Sciences


Department of Biological Sciences


More than half the North American freshwater mussel species in the family Unionidae (unionids) are imperiled or extinct. Alteration of rivers is considered a major contributor to unionid population declines. Losses could occur through disruption of the reproductive cycle. Unionid reproduction requires attachment of larva (glochidia) to host fishes; therefore, changes in the host fish community could alter the reproductive potential in unionid communities. There have been few attempts to compare reproductive success before and after alteration. I examined the pattern of glochidia use on two common host fishes, Lepomis megalotis and Cyprinella venusta, before and after alteration of the Tombigbee River. While both host species declined in the river, the number of glochidia per infested fish and proportion of infested fish increased post-impoundment in L. megalotis but not C. venusta. My results demonstrate the importance of considering reproductive changes as a driver of unionid mussel declines in North America.