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Breviata anathema is one of just a few described species of 'breviates', a recently discovered group of free-living protozoa that live in oxygen-poor saline habitats. Breviata anathema is a small single celled organism that can swim though fluids using its single flagellum (though some other 'breviates' have two flagella), but more often slowly creeps across surfaces in an amoeboid form. Creeping breviates usually extend fine pseudopodia from the anterior portion of the cell at regular intervals. These extend laterally and fix to surface, leading to a 'caterpillar track' effect as the cell moves forward past its own pseudopodia. The pseudopodia are also used to ingest bacterial prey. The mitochondrial organelles of breviates lack the ability to perform aerobic respiration, a feature they share with many protozoa from similar habitats. More surprisingly, in at least one breviate (Pygsuia biforma), the standard mitochondrial iron-sulfur cluster assembly machinery (the ISC system) has been replaced by a 'SUF system' acquired from Archaea. It has recently been demonstrated that breviates are amongst the closest relatives of Opisthokonta, the taxonomic group that includes both animals and true fungi. Researchers are now examining systems involved in multicellularity in animals (e.g. cell adhesion and communication systems) to determine whether there are recognizable antecedents of these systems in breviates (and other single-celled relatives of animals).