Fig. 3.

16S rDNA-based phylogenetic tree based on Treepuzzle analysis showing the relationship of the Robbea symbionts (in bold) with other stilbonematid and oligochaete symbionts, as well as other bacteria belonging to the Chromatiaceae and other vestimentiferan and mussel symbionts. Treepuzzle support values are depicted above the respective branches and maximum parsimony bootstrap values below the branches. Only Treepuzzle support values above 75% are displayed. The scale bar represents 10% estimated sequence divergence.