What Drives Sponge Symbioses?
Ute Hentschel Humeida
Professor of Marine microbiology, RD3 Marine Symbioses,
GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany
The term “holobiont” (syn. “metaorganism”) was coined in recognition of the fact that in the environment, all multicellular hosts (animals, plants) associate with microorganisms. The concept has profound impacts on our understanding of ecology which seeks to understand the interactions between organisms and between organisms and their environment. There is a growing awareness that such microbial communities may fulfill many essential functions, from nutrition to development and defense against pathogens. Sponges are excellent examples of such holobionts, because many species harbor enormously dense and diverse communities of symbiotic microorganisms in their tissues. More than 40 bacterial phyla and candidate phyla as well as two archaeal lineages representing potentially thousands of symbiont lineages per sponge individual have been recorded. This diverse array of microbial communities has received considerable research attention over the last two decades and the mechanisms of host-microbe interactions within the sponge holobiont and with its environment are beginning to be understood. This presentation will attempt to provide answers to the question of what drives sponge symbioses.