Date of Award

Spring 1995

Document Type



Life & Environmental Sciences

First Advisor

John Addis

Second Advisor

Marilyn Schendel

Third Advisor

Joan Stottlemyer


Assays based on histocompatibility were used to test whether sponges belonging to the species Ephydatia muelleri and Spongilla lacustris occupy single clonal populations. The histocompatibility assay consists of two individual sponges of the same species being bound together to form a sample pair. After seven days the sample pairs were observed as exhibiting fusion or non-fusion. Two individuals that did not fuse with each other were considered to be of different strains. The results show that neither species of sponge, E. muelleri or S. lacustris. grow as a single clonal population in Salmon Lake. Three strains of E. muelleri and two strains of S. lacustris were identified.