Date of Award

Spring 1998

Document Type



Life & Environmental Sciences

First Advisor

John Addis

Second Advisor

Guido Bugni

Third Advisor

Joan Stottlemyer


Allozyme electrophoresis was used to discriminate between two types of freshwater sponges that previously could not be distinguished using morphological criteria. One of these types was a well-characterized species, Ephydatia muelleri, whereas the other could not be identified because of an absence of gemmules and gemmoscleres, structures on which classification of freshwater sponges largely depends. Homogenates prepared from five individuals of each sponge type were electrophoresed in cellulose acetate gels. The gels were then stained to localize bands of enzyme activity. Analyzing the stained gels revealed migration rates of hexokinase and sorbitol dehydrogenase that differed between the two sponge types. The absence of any electrophoretic bands common to the two sponge types argues that the sponges are different species.