CC BY
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6 • "PROTIST—2016
belonging to Spirotrichs. Maximum number of oxytrichids were found in Rithala sewage site though ciliate diversity was less. Maximum ciliate diversity was found in ANDC whereas ciliate diversity was less in Karnal. Colpodids were present in all the sites examined but most abundant in sewage site. Variation in soil ciliate diversity can be correlated with soil quality of studied habitats.
SOIL PROTIST BACTERIA CONSUMPTION IS CENTRAL TO NUTRIENT CYCLING Adl S.M.
University ofSaskatchewan [email protected]
Protists are the most abundant consumers of bacteria in soils. Their diversity covers most lineages making them the most diversity group of organisms in soils. Communities assemble along abiotic microgradients, such as pO2, pCO2, pH, temperature, etc. Species of protist bacterivores are not homologous or interchangeable. Species in functional groups have differing ecological preferences, occupying distinct niches. There are significant measurable species specific differences regarding prey ingestion rates and prey preferences. It has been well recognised in both soil and aquatic ecology that ignoring inter-species variability in behaviour and consumption rates is problematic. The top-down grazing pressure on bacteria was calculated for a variety of species representing a variety of feeding types, from functional response curves. We calculated threshold prey levels that sustained growth and initial rate slopes for ingestion rates, to compare competitive ability at low food conditions. Together with maximum growth rates and maximum ingestion rates inter-specific competitiveness and niche preferences could be distinguished. Data will be presented for several well established cercozoa cultures, amoebae cultures, ciliates, and other protists. This information helps to improve our calculations of global bacteria biomass turnover rates in soils. It also helps to understand how soils can support dozens of bacterivorous species in each gram of soil, in a seemingly similar habitat.
BIODIVERSITY STUDIES IN LORICATE PROTISTS: THE CASE OF TINTINNIDS (ALVE-OLATA, CILIOPHORA, SPIROTRICHA) Agatha S.1, Santoferrara L.F.2
1 - Dept. of Ecology and Evolution, University of Salzburg, Salzburg, Austria
2 - Dept. Marine Sciences, University of Connecticut, Groton, Connecticut, USA [email protected]
Species identification is crucial in biodiversity research (ecology, taxonomy, barcoding etc.). In tintinnids, taxonomy and classification are almost exclusively based on features of their vase-shaped loricae (houses). The lorica-based species circumscriptions are, however, problematic as loricae might show a considerable intraspecific variability and interspecific similarity and might be influenced by the cell cycle and physico-chemical factors. To overcome the difficulties with deviating species limitations suggested by "lumpers" or "splitters" in revisionary treatises, it is recommend to "go back to the roots", i.e., to use exclusively the original descriptions or authoritative redescriptions for identification. Additionally, good documentation of the identified loricae by means of illustrations and morphometric data is advisable. Depending on the aim of the tintinnid study, further procedures are proposed to generate at high rates long-lasting high-quality species re-/ descriptions and/or DNA barcodes, which are essential for reliable phylogenetic analyses and thus for the establishment of a natural tintinnid classification. These suggestions represent a compromise between data quality and work effort and can most easily be followed by collaborations of molecular biologists and morphologic taxonomists. Financially supported by FWF project P28790.
MICROBIAL EUKARYOTES IN OILSANDS-ASSOCIATED ENVIRONMENTS OF NORTHERN ALBERTA
Aguilar M.1, Richardson E.1, Paoli L.2, Nesbo C.3, Foght J.3, Dunfield P.F.4, Dacks J.B.15
1 - Department of Cell Biology, University of Alberta. Edmonton, Canada
2 - Département de Biologie, Ecole normale supérieure, Paris, France
3 - Department of Biological Sciences, University of Alberta, Edmonton, Canada
4 - Department of Biological Sciences, University of Calgary, Calgary, Canada
5 - Department of Life Sciences, Natural History Museum, London, UK
The oil sands in Northern Alberta are the second largest bitumen deposit in the world, and comparable in magnitude to world's reserves of conventional petroleum. They have global significance as energy reservoirs. However, some aspects of their exploitation are also cause for environmental concern. Fluid wastes from bitumen extraction are retained in enormous tailings 'ponds' under a policy of no release to the environment. The estimated surface area of tailings ponds in Alberta ranges from 77-176
