Diversity and evolutionary origin of Polish freshwater dinoflagellates

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Unambiguous scientific names are the prerequisite for proper identification and therefore any subsequent application of biological species. Unicellular organisms, which can only be identified under the microscope, are particularly prone to taxonomic confusion, and corresponding standard (i.e., type) material often is poorly preserved or entirely lost. Recently, molecular methods have become an essential tool to resolve identification issues. An ecologically and economically important group of unicellular plankton organisms are dinoflagellates, the subject of this proposal. Poland is the country, from which the greatest number of freshwater dinoflagellate species have been described, partly a century ago. With more than 10,000 lakes mostly originated during the past Glacial Maximum, the country is also an extraordinary system to study evolutionary diversification of freshwater organisms. Here we aim to collect living material at type localities and to establish living strains, allowing re-investigation of the corresponding algae. Study of morphology using light and electron microscopy will circumscribe Polish species and will shed more light on character evolution in dinoflagellates. Phylogenetic relationships will be inferred from molecular trees based on rRNA and other informative loci using maximum likelihood methods. We will test whether freshwater dinoflagellates are widely distributed across Europe or rather occur in isolated habitats (such as lakes) as endemic species. Composition of dinoflagellate communities may result from both a) radiations after recent transitions from the marine into the freshwater environment as well as b) adaptation to freshwater prior to the formation of the Baltic Ridge older then the Plesitocene and subsequent dispersal to the current habitats. Timing divergence events will further enlighten origin and diversification of Central European freshwater dinoflagellates. Results of this project will contribute to the permanent documentation of the morphological and molecular diversity of dinoflagellates in public data bases and collections.