Cercomonads are small flagellates, widespread in aqueous habitats and common in soils.

Characteristics

The cells are generally around 10 μm in length, without any shell or covering. They produce filose

pseudopod A pseudopod or pseudopodium (plural: pseudopods or pseudopodia) is a temporary arm-like projection of a eukaryotic cell membrane that is emerged in the direction of movement. Filled with cytoplasm, pseudopodia primarily consist of actin filament ...

s to capture

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of prokaryotic microorganisms. Typically a few micrometr ...

, but do not use them for locomotion, which usually takes place by gliding along surfaces. Most members have two flagella, one directed forward and one trailing under the cell, inserted at right angles near its anterior. The

nucleus Nucleus ( : nuclei) is a Latin word for the seed inside a fruit. It most often refers to: *Atomic nucleus, the very dense central region of an atom * Cell nucleus, a central organelle of a eukaryotic cell, containing most of the cell's DNA Nucl ...

is connected to the flagellar bases and accompanied by a characteristic paranuclear body.

Classification

Genetic studies place the cercomonads among the Cercozoa, a diverse group of amoeboid and flagellate protozoans. They are divided into two families. * The Heteromitidae tend to be relatively rigid, and produce only temporary pseudopods. * The Cercomonadidae are more plastic, and when food supplies are plentiful may become

amoeboid An amoeba (; less commonly spelled ameba or amœba; plural ''am(o)ebas'' or ''am(o)ebae'' ), often called an amoeboid, is a type of cell or unicellular organism with the ability to alter its shape, primarily by extending and retracting pseudopo ...

and even

multinucleate Multinucleate cells (also known as multinucleated or polynuclear cells) are eukaryotic cells that have more than one nucleus per cell, i.e., multiple nuclei share one common cytoplasm. Mitosis in multinucleate cells can occur either in a coordina ...

. The classification of genera and species continues to undergo revision. Some genera have been merged, like ''Cercomonas'' and '' Cercobodo''. Others like '' Helkesimastix'', '' Sainouron'' and ''

Cholamonas Cercomonads are small flagellates, widespread in aqueous habitats and common in soils. Characteristics The cells are generally around 10 μm in length, without any shell or covering. They produce filose pseudopods to capture bacteria, but do n ...

'' have been moved to Helkesida, while the rest of the family Heteromitidae has been moved to Glissomonadida. * Order Cercomonadida Poche 1913 sensu Bass et al. 2009 ** Genus '' Paracercobodo'' Hovasse & Combescot 1959 ** Family ? Krakenidae Dumack, Mylnikov & Bonkowski 2017 *** Genus '' Kraken'' Dumack et al. 2016 ** Family Paracercomonadidae Cavalier-Smith & Karpov 2012 *** Genus '' Brevimastigomonas'' Brabender et al. 2012 *** Genus '' Metabolomonas'' Brabender et al. 2012 *** Genus '' Nucleocercomonas'' Brabender et al. 2012 *** Genus '' Paracercomonas'' Cavalier-Smith & Bass 2006 ** Family Cercomonadidae Kent 1880 sensu Karpov et al. 2006 ercobodonidae Hollande 1942*** Genus '' Eocercomonas'' Karpov et al. 2006 *** Genus '' Filomonas'' Cavalier-Smith & Karpov 2012 *** Genus '' Cavernomonas'' Vickerman 2009 *** Genus '' Cercomonas'' Dujardin 1841 emend. Karpov et al. 2006 non emend. Ekelund et al. 2004 [''Neocercomonas'' Ekelund, Fredslund & Daugbjerg 2004; ''Cercobodo'' Krassilstschick 1886; ''Cercomastix'' Lemmermann 1913; ''Dimastigamoeba'' Blochmann 1894; ?''Mukdeniamonas'' Skwortzov 1960; ?''Changia'' Skwortzov 1960 non Sun 1924; ?''Reptomonas'' Kent 1880; ''Dimorpha'' Klebs 1892 non Gruber 1882] *** Genus ''Neocercomonas'' Ekelund, Daugbjerg & Fredslund 2004

References

{{Taxonbar, from=Q724194 Cercomonadida, Cercozoa orders