Paracatenula, an ancient symbiosis between thiotrophic Alphaproteobacteria and catenulid flatworms
by Harald Ronald Gruber-Vodicka, Ulrich Dirks, Nikolaus Leisch, Christian Baranyi, Kilian Stoecker, Silvia Bulgheresi, Niels Robert Heindl, Matthias Horn, Christian Lott, Alexander Loy, Michael Wagner, and Jörg Ott
PNAS 2011 - published ahead of print June 27, 2011, doi:10.1073/pnas.1105347108
The article is open access - go to http://www.pnas.org/content/early/2011/06/22/1105347108
You should really watch the Paracatenula movie here and you might as well read the University press release here.
First detection of thiotrophic symbiont phylotypes in the pelagic marine environment by Niels R. Heindl, Harald R. Gruber-Vodicka, Christoph Bayer, Sebastian Lücker, Joerg A. Ott, Silvia Bulgheresi
FEMS Microbiology Ecology 77:1 223-227 - online here
"Sequence variability of the pattern recognition receptor Mermaid mediates specificity of marine nematode symbioses" by Silvia Bulgheresi*, Harald R Gruber-Vodicka*, Niels R Heindl, Ulrich Dirks, Maria Kostadinova, Heimo Breiteneder and Joerg A Ott
*these authors contributed equally
ISME Journal 5, 986–998 - online here