[citation needed] Members of this family are all obligate anaerobes, and occur in habitats such as rivers, lakes, and the intestines of vertebrates.
They range from spherical forms, such as Megasphaera and Veillonella, to curved rods, as typified by the Selenomonads.
[2] Selenomonas has a characteristic crescent-shape, with flagella inserted on the concave side, while Sporomusa is similar but non-motile.
[3] The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN)[4] and National Center for Biotechnology Information (NCBI)[5] Veillonella Megasphaera [incl.
Allisonella] Megasphaera paucivorans Juvonen & Suihko 2006 Anaeroglobus Carlier et al. 2002 (incl.