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A large-scale investigation of warm water loricate choanoflagellate communities has revealed the presence of close to 80 species, which is approximately half of all loricate choanoflagellate taxa described when including also hitherto undescribed forms known to us. We are in the process of stepwise providing a monographic treatment of these communities. The overall aim is to contribute the best possible account of species diversity, based on traditional light and electron microscopical techniques, as a tool for future identification work based on microscopy, and in support of the work in progress with establishing a quality assured molecular tool for future recognition of diversity. In this paper we summarize our findings of species of Acanthocorbis and Stephanoeca , which include the description of several new taxa: A. conicella sp. nov., A. gladiella sp. nov., S. broomia sp. nov., S. naja sp. nov., and S. andemanica sp. nov. [ABSTRACT FROM AUTHOR]

Sex is found in all major eukaryotic groups of organisms. It has been known for some time that the choanoflagellates also possess the genes involved in meiosis and a full sexual cycle was also recently accounted for in Salpingoeca rosetta . With reference to the loricate choanoflagellates the current status is that only circumstantial evidence, from wild material of Bicosta spinifera , exists in favour of documenting division patterns that go beyond plain asexual division, and that has the potential to represent stages in a sexual life cycle. Here we present further evidence from wild material documenting possible morphotype changes that might similarly indicate the existence of complex life cycles. In this particular case, it revolves around the existence of so-called ‘combination loricas’ (i.e. two loricas that occur physically united), representing consistent species combinations from the genera Acanthocorbis and Stephanoeca . [ABSTRACT FROM AUTHOR]

Abstract: A new acanthoecid choanoflagellate species, Acanthocorbis mongolica sp. nov. was found in preserved phytoplankton samples from the freshwater lake Bayan Nuur (Uvs Nuur Basin, NW Mongolia) in concentrations of up to 1.8×105 cellsL−1. It is the first well-documented species of the mainly marine order Acanthoecida to be found in a freshwater lake. The lorica structures were studied with scanning electron microscopy. Key morphological features of the vase-shaped lorica are spine bases that are composed of multiple (2–4) parallel costal strips, and the existence of two transverse costae. The ecological implications of this find are discussed. [Copyright &y& Elsevier]