Biodiversity of Marine Tintinnids (Protista, Ciliophora)

The project is addressed to the main questions in ciliate alpha-taxonomy and the hotly debated problems in biodiversity. Its results should allow an estimation of the biogeography of a species-rich group of marine plankton protists, i.e., the tintinnids. Tintinnid ciliates (Protozoa, Ciliophora, Oligotrichea) are an important component of the marine microzooplankton. They feed on autotrophic nanoflagellates and thus influence sequestration of CO 2 and global warming. Furthermore, harmful and/or bloom-forming algae are ingested by some species. Our understanding of ecosystem functioning largely depends on the identification of the species involved and the detailed knowledge about their ecology. However, the last comprehensive tintinnid revisions date back to the years 1929 and 1939, and tintinnid morphology and diversity are still poorly explored. The majority of the ~ 1200 tintinnid species has been established, using minute differences in the shape, size, and surface texture of the lorica (house), although these features apparently have a considerable phenotypic plasticity. Accordingly, it has been proposed that the number of real species is distinctly lower. On the other hand, cell morphology has been investigated in only 18 species, and possibly hundreds of distinct species might be distinguishable by cell features. Thus, the proposed project will perform a unique and comprehensive study of the cell morphology in more than 30 tintinnid species and an analysis of the intraspecific cytological variability in correlation with their temporal and spatial distribution and some environmental factors. The findings will assess whether several cytologically distinct populations (pseudocryptic species) underlie a "Formenkreis" (group of similar loricae) or whether a single species possesses multiple lorica morphotypes. Furthermore, my results will allow a delimitation of species, an estimation of the real tintinnid diversity, and an assessment of the biogeography, including literature data. Additionally, the descriptions of the species will be extraordinary in the respect that they will be based on several populations studied in vivo, after protargol impregnation, and in the electron microscope. A collaboration with pending French and American projects will provide a unique opportunity for a synergistic study, connecting morphological, genetical, biochemical, and ecological data for tintinnid species definitions and a far-reaching estimation of tintinnid diversity and biogeography. Morphological taxonomy as a distinct scientific field is threatened by extinction because the number of alpha- taxonomists drastically decreases. Therefore, the present project will not only strengthen Austria as a "hot-spot" for ciliate taxonomy, but will also enable training of students in the basics of ciliate taxonomy.

The project is addressed to the main questions in ciliate alpha-taxonomy and the hotly debated problems in biodiversity. Its results should allow an estimation of the biogeography of a species-rich group of marine plankton protists, i.e., the tintinnids. Tintinnid ciliates (Protozoa, Ciliophora, Oligotrichea) are an important component of the marine microzooplankton. They feed on autotrophic nanoflagellates and thus influence sequestration of CO 2 and global warming. Furthermore, harmful and/or bloom-forming algae are ingested by some species. Our understanding of ecosystem functioning largely depends on the identification of the species involved and the detailed knowledge about their ecology. However, the last comprehensive tintinnid revisions date back to the years 1929 and 1939, and tintinnid morphology and diversity are still poorly explored. The majority of the ~ 1200 tintinnid species has been established, using minute differences in the shape, size, and surface texture of the lorica (house), although these features apparently have a considerable phenotypic plasticity. Accordingly, it has been proposed that the number of real species is distinctly lower. On the other hand, cell morphology has been investigated in only 18 species, and possibly hundreds of distinct species might be distinguishable by cell features. Thus, the proposed project will perform a unique and comprehensive study of the cell morphology in more than 30 tintinnid species and an analysis of the intraspecific cytological variability in correlation with their temporal and spatial distribution and some environmental factors. The findings will assess whether several cytologically distinct populations (pseudocryptic species) underlie a "Formenkreis" (group of similar loricae) or whether a single species possesses multiple lorica morphotypes. Furthermore, my results will allow a delimitation of species, an estimation of the real tintinnid diversity, and an assessment of the biogeography, including literature data. Additionally, the descriptions of the species will be extraordinary in the respect that they will be based on several populations studied in vivo, after protargol impregnation, and in the electron microscope. A collaboration with pending French and American projects will provide a unique opportunity for a synergistic study, connecting morphological, genetical, biochemical, and ecological data for tintinnid species definitions and a far-reaching estimation of tintinnid diversity and biogeography. Morphological taxonomy as a distinct scientific field is threatened by extinction because the number of alpha-taxonomists drastically decreases. Therefore, the present project will not only strengthen Austria as a "hot-spot" for ciliate taxonomy, but will also enable training of students in the basics of ciliate taxonomy.