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Date of Award

Spring 2007

Document Type

Restricted Thesis: Campus only access

Degree Name

Bachelor of Science



First Advisor

Dr. Malcolm Hill


Sponges are an appropriate organism for studying biodiversity because of the significant portion of their biomass composed of microbial biota. These sponge-microbe associations are suggested to benefit the host in several ways including secondary metabolite production, and current research has suggested that some of these metabolites recovered from sponges and their symbionts have antimicrobial, cytotoxic, and antitumor activities. With our ever-changing environment, it is becoming increasingly significant to study bacterial symbiont stability for not only their pharmaceutical and biotechnological importance but their ecological and evolutionary significance as well. Denaturing gradient gel electrophoresis (DOGE) of amplified bacterial ribosomal DNA was used to detect patterns and changes in symbiont communities of the sponge Clathria prolifera temporally, under environmentally stressful conditions, and through transmission. Transmission electron microscopy (TEM) and fluorescence in situ hybridization (FISH) were used to investigate the distribution of symbionts in the sponges Halichondria bowerbanki and Chondrilla nucula respectively. Molecular results supported that changes occur in the symbiont community under many conditions, both naturally and stressed, and microscopy results illustrated the great diversity and distribution of bacteria in sponge tissue.