Date of Award

Fall 12-7-2018

Degree Type


Degree Name

Master of Science in Integrative Biology (MSIB)



Committee Chair/First Advisor

Dr. Joseph Dirnberger

Major Professor

Dr. William Ensign

Second Committee Member

Dr. Joel McNeal


Pleurocerid snail diversity in the Southeastern United States is thought to be high, but estimates of overall diversity are compromised by uncertain taxonomy. This is particularly true for the genus Elimia, where reliance on conchological characters described by early naturalists for species designation failed to recognize significant variability in shell morphology. In this study we examine three putative species of Elimia to determine if quantifiable conchological characters are associated with differences in life history characteristics. Individuals of E. modesta, E. carinocostata, and E. cariniferawere collected from nine sites in three streams in the lower Etowah River Basin. Females were separated by species and placed in mono-specific tanks where egg deposition could be monitored. Shell shape was assessed using Geometric Morphometrics. Although there was some overlap, shell shapes differ significantly among the three forms. Shell sculpture differences appear early in juvenile forms and the three species are distinguishable by the establishment of the fourth whorl. Differences in egg oviposition among species were observed in the lab and in substrate samples obtained from the field. Our results suggest that there are at least three distinct species of Elimia occurring in lower Etowah River Basin tributaries.