The struggle to survive
Instead of taking up food with the mouth, little gutless tubeworms house sulfur bacteria in their body. They pick them up from the environment as soon as they settle on rocks after dispersing as larvae in the water. Tubeworms provide shelter for the bacteria. They feed their symbionts with inorganic gases so that they can grow like plants on land. In return the symbionts provide food to the tubeworm host so that they grow and reproduce in the absence of a digestive system. Both partners benefit from each other in this mutualistic relationship. However, life may be short because vent fluid eventually ceases. What happens to the bacteria after a tubeworm dies? They are trapped in a dead body that decays without gases to sustain autotrophic growth. Not to die with their host, the symbionts must leave the dead tubeworm.
How they manage we study in high-pressure aquaria where we incubate live symbionts in dead host tissue. We offer them food like sugar to investigate whether they can switch to a heterotroph life style during their escape. Such experiments were done during the cruise to the East Pacific Rise with the research vessel Atlantis and collecting samples with the submersible Alvin in October 2016.
Go to the blog in facebook hydrothermal vent for more details.
What do anemone, shipworms, roundworms and clams have in common?
The first course in Marine Microbial Symbiosis took place at the Institute of Marine Biology in Piran, Slovenia in July 2016. Supported by the teachers Monika Bright and Silvia Bulgheresi, the tutor Lukas Schuster and the PhD students Gabriela Paredes and Salvador Espada Hinojosa, the eleven students of the course investigate four different symbioses: the anemone Anemonia viridis and its photoautotrophic microalgae, the shipworm Teredo navalis and its nitrogen-fixing bacteria, a newly discovered stilbonematinae roundworm Eubostrichus sp. and its chemoautotrophic ectosymbionts, and the clam Loripes lacteus and its chemoautotrophic endosymbionts.
To follow the course, go to facebook – hydrothermal vent
Julia Klose completes her PhD
Julia Klose defended her Ph.D. thesis successfully on March, 26, 2016. Congratulations!
Prof. Horst Felbeck from Scripps Institution of Oceanography, San Diego, Prof. François Lallier from SNRS UPMC Station Biologique Roscoff, and Dr. Silvia Bulgheresi from the University of Vienna were the examiners of her thesis committee headed by the study program director Prof. Walter Jäger.
She has moved on to Dr. Jillian Petersen lab, Forschungsverbund Chemistry meets Microbiology, as postdoc to work on the lucinid clam symbiosis. Since her new lab is located in the same building, fortunately we still see her often.
Hertha Firnberg grant on “Benthic Ecosystem Functioning across Arctic Shelves, Slopes and Basins” to Renate Degen
Renate Degen received the three-year Hertha Firnberg grant from the Austrian Science Fund (FWF) to study the functions of macro- and megabenthic communities in the Arctic Ocean. While in recent years some information was gathered about the structural variability of Arctic benthos, information on the functional variability is currently still lacking. The aim of this project is to fill these knowledge gaps by means of a pan-Arctic, integrated approach, including i) the analysis of benthic functioning on Arctic shelves and basins and along a shelf-slope-basin gradient in the Eurasian and the Amerasian part of the Arctic, ii) the identification of functions and regions most susceptible to changes, and iii) the prediction of benthic ecosystem functioning in a future, seasonally ice free Arctic Ocean.