FWF / Project P 17752: “A Revision of Aloricate Oligotrichea (Ciliophora, Spirotricha), a Group of Ecologically Important Ciliates” – Grant amount: € 155.160. Period: 01.01.2005–31.12.2007
The major goal of the research project was to compile the knowledge about the aloricate Oligotrichea (Protista, Ciliophora) in a monograph. This kind of organisms represents an important link in the planktonic (water column) food web of marine and freshwaters, often dominating the community of minute, unicellular animals. Since the last revisions of the aloricate Oligotrichea, many new species were discovered and new investigation methods were introduced, e.g., cell staining techniques and electron microscopy. Due to the fragmented publication of the descriptions in many different journals and thus out of ignorance, the same species was occasionally described under different names. On the other hand, misidentifications caused a lumping of different species under the same name. After the fresh revision of the aloricate Oligotrichea in the monograph, 160 species are regarded as valid, while further descriptions are too insufficient to allow an unequivocal identification of the species. Taking this reassessment of the aloricate Oligotrichea, it was possible to connect the descriptions of the individual species with the ecological and biogeographical data (e.g., food items and spatial distribution) and to affiliate all available illustrations (line drawings and photos). Moreover, own descriptions of a new species, a new genus, and a new subgenus as well as improved descriptions of five further species were incorporated into the monograph. The detailed survey of the data, including new own results about the cell morphology, ultrastructure, cell division pattern, sexual behaviour, and morphology of the resting cysts (capsules enclosing the cell during uncomfortable conditions) allowed for the first time the reconstruction of the evolution in the Oligotrichea. The comparison of the “morphologic” tree and the gene tree, to which data of four further species could be added, revealed congruities, but also mismatches; further studies are required to reconcile both kinds of genealogies by incorporating new morphologic and genetic data. The improved insight into the cell morphology of aloricate Oligotrichea permitted the establishment of identification keys guiding even non-specialists to the species descriptions. Hence, the monograph with about 750 pages, 2,500 line drawings, and 1,350 photos will serve as an essential guide to the taxa and a valuable tool for all who deal with the identification and ecology of ciliates.
Link zu FWF-Projekt P 17752
Project associated publications:
- Agatha S., Strüder-Kypke M. C., Beran A. & Lynn D. H. (2005): Pelagostrobilidium neptuni (Montagnes and Taylor, 1994) and Strombidium biarmatum spec. (Ciliophora, Oligotrichea): phylogenetic position inferred from morphology, ontogenesis, and gene sequence data. Europ. J. Protistol. 41: 65–83. https://doi.org/10.1016/j.ejop.2004.09.005
- Agatha S. & Riedel-Lorjé J. C. (2006): Redescription of Tintinnopsis cylindrica Daday, 1887 (Ciliophora, Spirotricha) and unification of tintinnid terminology. Acta Protozool. 45: 137–151.
- Agatha S. & Strüder-Kypke M. C. (2007): Phylogeny of the order Choreotrichida (Ciliophora, Spirotricha, Oligotrichea) as inferred from morphology, ultrastructure, ontogenesis, and SSrRNA gene sequences. Europ. J. Protistol. 43: 37–63. https://doi.org/10.1016/j.ejop.2006.10.001
- Foissner W., Müller H. & Agatha S. (2007): A comparative fine structural and phylogenetic analysis of resting cysts in oligotrich and hypotrich Spirotrichea (Ciliophora). Europ. J. Protistol. 43: 295–314. https://doi.org/10.1016/j.ejop.2007.06.001
- Agatha S. & Tsai S.-F. (2008): Redescription of the tintinnid Stenosemella pacifica Kofoid and Campbell, 1929 (Ciliophora, Spirotricha) based on live observation, protargol impregnation, and scanning electron microscopy. J. Euk. Microbiol. 55: 75–85. https://doi.org/10.1111/j.1550-7408.2008.00309.x
- Agatha S. & Foissner W. (2009): Conjugation in the spirotrich ciliate Halteria grandinella (Müller, 1773) Dujardin, 1841 (Protozoa, Ciliophora) and its phylogenetic implications. Eur. J. Protistol. 45: 51–63. https://doi.org/10.1016/j.ejop.2008.07.004
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