Free-living Heterotrophic Flagellates from Freshwater Sites in Tasmania (Australia), a Field Survey

In order to contribute to an understanding of the geographic distribution of free-living freshwater flagellates, we have investigated the diversity of heterotrophic flagellates occurring in a number of freshwater sites in Tasmania (Australia). This community of organisms has not previously been studied in Tasmania, and the isolation of the freshwater habitats from like habitats elsewhere in the world increases the probability of the emergence of an endemic community. Forty-four species are described with uninterpreted records based on lightmicroscopy of living cells in natural communities. The records include an account of one new species: Ploeotia tasmanica sp. n. Of the 44 species (excluding unidentified taxa), 23 species are new to Australian freshwater sites but the majority of the species encountered here have also been found at other locations worldwide including Australian marine sites. The new records for Australian freshwater sites are: Adriamonas peritocrescens, Ancyromonas sigmoides, Astasia cfr. gomphonema, Bodo saltans, Ciliophrys infusionum, Colpodella vorax, Goniomonas truncata, Gyromonas ambulans, Heteromita globosa, Heteronema exaratum, H. globuliferum, Microcometes paludosa, Neobodo designis, N. saliens, Parabodo caudatus, Petalomonas poosilla, Ploeotia tasmanica sp. n., Protaspis obliqua, P. simplex, Reclinomonas americana, Rhynchomonas nasuta, Trepomonas agilis, Urceolus cyclostomus. The relative lack of novelty provides little support for the existence of endemic biota among this group of organisms, as has been shown to also be the case with marine species. This suggests that contiguity of habitats has not been a major determinant of the distribution of heterotrophic flagellates.