Cavanaugh 9314457 This project will study the biogeography of chemoautotrophic symbioses in marine oligochaetes. The objectives are to answer the following questions: Are the symbionts species-specific? What are their phylogenetic relationships among each other, to symbionts from other marine phyla, and to free-living bacteria? Are the symbionts within a monophyletic host group themselves monophyletic? If they did not co-evolve with their host, is the symbiont distribution paralleled by its ecological or geographic distribution? These questions can be addressed with a technically straightforward approach by analyzing the ribosomal RNA sequences of the prokaryotic symbionts in hosts from four geographically distant locations (Bermuda, Belize, Australia and the New England coast). The significance of the project lies in its ability to characterize for the first time the taxonomy, phylogeny, and biogeography of chemoautotrophic symbionts in a phylum previously not investigated. The results will show how wide spread the symbioses are and contribute to a better understanding of the biodiversity of chemoautotrophic symbioses in marine habitats. ***
