Overlap and discrepancies between ecotypes, genotypes and morphotypes of Antarctic and Arctic nanofauna
Professor Dr. Hartmut Arndt
Universität zu Köln
Heterotrophic nanoflagellates are major consumers of bacteria in the polar regions and contribute significantly to the carbon flux from DOC via bacteria to larger organisms such as ciliates and metazoans. Heterotrophic flagellate biomass may greatly exceed bacterial biomass in the sea ice. According to our recent molecular biological and morphological studies of Antarctic and Arctic nanofauna, morphological investigations reveal only limited taxonomic resolution for these tiny organisms (mainly 2-8um cell size). Many morphotypes contain several genotypes with sometimes high evolutionary distances (p-distances of SSU rDNA). To study the role of endemism in polar waters, we want to analyze discrepancies and overlaps between morphotypes, genotypes and ecotypes of selected nanoflagellates to draw conclusions regarding the possible effects of small changes in temperature on the sensitive Antarctic and Arctic ice biota. We will take samples from Antarctic and Arctic sites, establish cultures of nanoflagellates and analyse them combining morphological, molecular biological and ecological methods. We will use new clonal cultures in addition to already established cultures of Antarctic and Arctic isolates to study the tolerance of single genotypes regarding temperature, salinity and food composition. Knowing more about the role of biodiversity of the most important bacterivorous components of Antarctic and Arctic ecosystems should support our understanding of ecological processes in polar regions.
Förderung von 2006 bis 2009