Cercomonads are small

flagellate A flagellate is a cell or organism with one or more whip-like appendages called flagella. The word ''flagellate'' also describes a particular construction (or level of organization) characteristic of many prokaryotes and eukaryotes and thei ...

s, 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 biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were am ...

, but do not use them for locomotion, which usually takes place by gliding along surfaces. Most members have two

flagella A flagellum (; ) is a hairlike appendage that protrudes from certain plant and animal sperm cells, and from a wide range of microorganisms to provide motility. Many protists with flagella are termed as flagellates. A microorganism may have fro ...

, 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 Cercozoa is a phylum of diverse single-celled eukaryotes. They lack shared morphological characteristics at the microscopic level, and are instead defined by molecular phylogenies of rRNA and actin or polyubiquitin. They were the first major euk ...

, a diverse group of amoeboid and flagellate protozoans. They are divided into two families. * The

Heteromitidae 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 ...

tend to be relatively rigid, and produce only temporary pseudopods. * The

Cercomonadidae 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 ...

are more plastic, and when food supplies are plentiful may become amoeboid 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 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 ...

'', ''

Sainouron 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 ...

'' 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

has been moved to

Glissomonadida The glissomonads are a group of bacterivorous gliding flagellated protists that compose the order Glissomonadida, in the amoeboflagellate phylum Cercozoa. They comprise a vast, largely undescribed diversity of soil and freshwater organisms. Th ...

. * Order Cercomonadida Poche 1913 sensu Bass et al. 2009 ** Genus '' Paracercobodo'' Hovasse & Combescot 1959 ** Family ? Krakenidae Dumack, Mylnikov & Bonkowski 2017 *** Genus ''

Kraken The kraken () is a legendary sea monster of enormous size said to appear off the coasts of Norway. Kraken, the subject of sailors' superstitions and mythos, was first described in the modern age at the turn of the 18th century, in a travelog ...

'' Dumack et al. 2016 ** Family

Paracercomonadidae The paracercomonads are a group of cercozoan protists. Taxonomically, they comprise the family Paracercomonadidae, order Paracercomonadida and subclass Paracercomonada. Due to their morphological similarities to the cercomonads, members of this ...

Cavalier-Smith & Karpov 2012 *** Genus '' Brevimastigomonas'' Brabender et al. 2012 *** Genus '' Metabolomonas'' Brabender et al. 2012 *** Genus '' Nucleocercomonas'' Brabender et al. 2012 *** Genus ''

Paracercomonas ''Paracercomonas'' is a genus of rhizaria. It includes the species ''Paracercomonas marina''. Species * '' P. ambulans'' Howe & Cavalier-Smith 2009 * '' P. astra'' Howe & Cavalier-Smith 2009 * '' P. baikali'' Howe et al. 2011 * '' P. bassi'' B ...

'' Cavalier-Smith & Bass 2006 ** Family

Kent 1880 sensu Karpov et al. 2006 ercobodonidae Hollande 1942*** Genus ''

Eocercomonas ''Eocercomonas'' is a genus of cercozoa Cercozoa is a phylum of diverse single-celled eukaryotes. They lack shared morphological characteristics at the microscopic level, and are instead defined by molecular phylogenies of rRNA and actin or p ...

'' Karpov et al. 2006 *** Genus '' Filomonas'' Cavalier-Smith & Karpov 2012 *** Genus '' Cavernomonas'' Vickerman 2009 *** Genus ''

Cercomonas 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 ...

'' 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