Variabilität und Diversität der Nanofauna in den Tiefseebecken des Mittelmeeres, des Südost- und Südwestatlantiks
Final Report Abstract
The abyssal seafloor is the largest benthic habitat on earth. The continuous nature of the habitat and the deep oceans flow regime suggest that extreme endemism amongst microbial eukaryotes may be rare. In the first part of this project, we used both evolutionary (SSU rDNA) and to some extent fast-evolving (ITS1 rDNA) genetic markers to study the distribution of several isolated strains of commonly found nanoflagellates from abyssal deep-sea sites of the South-East Atlantic and the Mediterranean. Our results show that at least some ribotypes of the opportunistic species studied have wide distribution ranges throughout the South-East Atlantic and, to a lesser extent, the Mediterranean, although potential endemism at abyssal depths cannot be ruled out. In the second part of this project, we studied the community structure of a specific class of microbial eukaryotes, the kinetoplastids. We analyzed samples from all abyssal plains of the South Atlantic as well as the Ierapetra Basin and Pliny Trench from the Eastern Mediterranean using partial small subunit ribosomal DNA gene clone libraries. Our analysis revealed very similar communities from both the South-East Atlantic (Angola and Guinea Basin) and the South-West Atlantic (Angola and Brazil Basin) at spatial scales of 1000—3000 km, whereas all other communities were significantly differentiated from one another. It seems likely that multiple processes operate at the same time to shape communities of deep-sea kinetoplastids, but constant and homogenous environmental conditions over large spatial scales at abyssal depths, together with high-dispersal capabilities of microbial eukaryotes, may best explain our findings of statistically indistinguishable communities at larger spatial scales. The PNAS-paper received considerable interest by the public press.
Publications
- (2010): Large-scale patterns in biodiversity of microbial eukaryotes from the abyssal sea floor. Proc. Nat. Acad. Sci. U.S.A 107(1): 115-120
Scheckenbach, F., Hausmann, K. Wylezich, C., Weitere, M., & Arndt, H.
- (2011) Novel cultured protists identify deep-branching environmental DNA clades of Cercozoa: new genera Tremula, Micrometopion, Minimassisteria, Nudifila, Peregrinia. Protist 162: 332-372
Howe, A.T., Bass, D., Scoble, J.M., Lewis, R., Vickerman, K., Arndt, H., Cavalier-Smith, T.
