On the Bacterial Endosymbionts of Placobdella (Annelida: Hirudinea: Glossiphoniidae)

The objective of this project was to survey the diversity of bacterial endosymbionts of the genus Reichenowia inhabiting the esophageal organs of the blood feeding leech genus Placobdella. I aimed to (1) place these symbionts in a phylogeny among other bacterial phyla, (2) compare the evolutionary histories of these symbionts with those of their hosts, and (3) to explore the mode of transmission between parent and offspring to shed light on the vertical transmission of the bacteria inside of the leeches. I confirmed the presence of bacteria in ten previously untested Placobdella species by recovering bacterial DNA from bacteriome tissues and used TEMs to capture bacterial morphology and their location within their host. Lastly, phylogenetic analyses based on 16S and 23S rRNA found Reichenowia to be a monphyletic group of bacteria placing within the alphaproteobacterial family Rhizobiaceae and found no evidence of expected cospeciation between hosts and symbionts.M.Sc