Mantamonas | |
---|---|
Scientific classification | |
Domain: | Eukaryota |
Clade: | Opimoda |
Clade: | CRuMs |
Class: | Glissodiscea Cavalier-Smith 2013 emend. 2021 [1] |
Order: | Mantamonadida Cavalier-Smith 2011 [2] |
Family: | Mantamonadidae Cavalier-Smith 2011 [2] |
Genus: | Mantamonas Cavalier-Smith & Glücksman 2011 [2] |
Type species | |
Mantamonas plastica Glücksman & Cavalier-Smith 2011 [2] | |
Species | |
Diversity | |
3 species [3] |
Mantamonads are a group of free-living heterotrophic flagellates that move primarily by gliding on surfaces (rather than swimming). They are classified as one genus Mantamonas in the monotypic family Mantamonadidae, order Mantamonadida and class Glissodiscea. [1] Previously, they were classified in Apusozoa as sister of the Apusmonadida on the basis of rRNA analyses. [2] [4] However, mantamonads are currently placed in CRuMs on the basis of phylogenomic analyses that identify their closest relatives as the Diphylleida and Rigifilida. [5] [6]
Mantamonas are heterotrophic unicellular protists. Their cells are flattened, relatively plastic and asymmetric. They have one thin anterior flagellum and one conspicuous posterior flagellum, on which they glide. The cells have a right hump, likely caused by the nucleus, and a blunt projection on the left side. They are typically 2 μm thick, [2] 5 μm long and 5 μm wide, but vary in size and shape depending on their growth phase and the bacterial density in the medium. [3] When wide-shaped, they present lateral "wings" that resemble the fins of a manta ray (hence the name Mantamonas). [3]
Mantamonas are marine gliding heterotrophic flagellates. M. plastica was isolated from marine sediments, while M. vickermani was isolated from marine lagoon sediments. M. sphyraenae was obtained from the skin surface of a barracuda, suggesting that it could be an epizootic species. [3]
When discovered in 2011, a phylogenetic analysis based on 28S and 18S rRNA recovered Mantamonas as a lineage closely related to Planomonadida and Apusomonadida, within the paraphyletic Apusozoa. [2] Later in 2018, a phylogenomic analysis recovered Mantamonas as the sister group of a clade comprising Collodictyonidae and Rigifilida. Together, the three groups compose the CRuMs clade, which is the sister group to Amorphea (Amoebozoa + Obazoa) in a clade known as Podiata. [6]
Eukaryota |
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
There are currently three species of Mantamonas. [3]
Amorphea is a taxonomic supergroup that includes the basal Amoebozoa and Obazoa. That latter contains the Opisthokonta, which includes the Fungi, Animals and the Choanomonada, or Choanoflagellates. The taxonomic affinities of the members of this clade were originally described and proposed by Thomas Cavalier-Smith in 2002.
The Apusozoa are a paraphyletic phylum of flagellate eukaryotes. They are usually around 5–20 μm in size, and occur in soils and aquatic habitats, where they feed on bacteria. They are grouped together based on the presence of an organic shell or theca under the dorsal surface of the cell.
Ancyromonas is a genus of basal Eukaryote consisting of heterotrophic flagellates.
Telonemia is a phylum of microscopic eukaryotes commonly known as telonemids. They are unicellular free-living flagellates with a unique combination of cell structures, including a highly complex cytoskeleton unseen in other eukaryotes.
Malawimonadidae is a family of unicellular eukaryotes of outsize importance in understanding eukaryote phylogeny.
Breviata anathema is a single-celled flagellate amoeboid eukaryote, previously studied under the name Mastigamoeba invertens. The cell lacks mitochondria, much like the pelobionts to which the species was previously assigned, but has remnant mitochondrial genes, and possesses an organelle believed to be a modified anaerobic mitochondrion, similar to the mitosomes and hydrogenosomes found in other eukaryotes that live in low-oxygen environments.
Bigyra is a phylum of microscopic eukaryotes that are found at the base of the Stramenopiles clade. It includes three well-known heterotrophic groups Bicosoecida, Opalinata and Labyrinthulomycetes, as well as several small clades initially discovered through environmental DNA samples: Nanomonadea, Placididea, Opalomonadea and Eogyrea. The classification of Bigyra has changed several times since its origin, and its monophyly remains unresolved.
The apusomonads are a group of protozoan zooflagellates that glide on surfaces, and mostly consume prokaryotes. They are of particular evolutionary interest because they appear to be the sister group to the Opisthokonts, the clade that includes both animals and fungi. Together with the Breviatea, these form the Obazoa clade.
Ancyromonadida or Planomonadida is a small group of biflagellated protists found in the soil and in aquatic habitats, where they feed on bacteria. Includes freshwater or marine organisms, benthic, dorsoventrally compressed and with two unequal flagellae, each emerging from a separate pocket. The apical anterior flagellum can be very thin or end in the cell membrane, while the posterior flagellum is long and is inserted ventrally or laterally. The cell membrane is supported by a thin single-layered theca and the mitochondrial crests are discoidal/flat.
Rigifilida is a clade of non-ciliate phagotrophic eukaryotes. It consists of two genera: Micronuclearia and Rigifila.
Podiates are a proposed clade containing the Amorphea and the organisms now assigned to the clade CRuMs. Ancyromonadida does not appear to have emerged in this grouping. Sarcomastigota is a proposed subkingdom that includes all the podiates that are not animals or fungi. Sulcozoa is a proposed phylum within Sarcomastigota that does not include the phyla Amoebozoa (clade) and Choanozoa (paraphyletic), i.e. it includes the proposed subphyla Apusozoa and Varisulca
Varisulca was a proposed basal Podiate taxon. It encompassed several lineages of heterotrophic protists, most notably the ancyromonads (planomonads), collodictyonids (diphylleids), rigifilids and mantamonadids. Recent evidence suggests that the latter three are closely related to each other, forming a clade called CRuMs, but that this is unlikely to be specifically related to ancyromonads
Obazoa is a proposed sister clade of Amoebozoa. The term Obazoa is based on the OBA acronym for Opisthokonta, Breviatea, and Apusomonadida, the group's three constituent clades.
CRuMs or Crumalia is a proposed clade of microbial eukaryotes, whose name is an acronym of the following constituent groups: i) collodictyonids also known as diphylleids, ii) rigifilids and iii) mantamonadids as sister of the Amorphea. It more or less supersedes Varisulca, as Ancyromonadida are inferred not to be specifically related to the orders Diphylleida/Collodictyonida, Rigifilida and Mantamonadida.
Syssomonas is a monotypic genus of unicellular flagellated protists containing the species Syssomonas multiformis. It is a member of Pluriformea inside the lineage of Holozoa, a clade containing animals and their closest protistan relatives. It lives in freshwater habitats. It has a complex life cycle that includes unicellular amoeboid and flagellated phases, as well as multicellular aggregates, depending on the growth medium and nutritional state.
Mantamonas sphyraenae is a species of marine heterotrophic flagellates described in 2021. It belongs to the Mantamonadida, a basal eukaryotic lineage within a clade known as CRuMs. Its diploid genome is the first to be assembled within the CRuMs group.
Mantamonas vickermani is a species of marine heterotrophic flagellates described in 2021. It belongs to the Mantamonadida, a basal eukaryotic lineage within a clade known as CRuMs.
Mantamonas plastica is a species of marine heterotrophic biflagellates described in 2011. It is the type species of the Mantamonadida, a basal eukaryotic lineage within a clade known as CRuMs.
Chelonemonas is a genus of heterotrophic protists. They are unicellular eukaryotes with two flagella, characterized by the presence of a honeycomb or turtle shell pattern on the dorsal surface of their cells that is visible under electron microscopy. They belong to the Apusomonadida, a clade of flagellates related to the opisthokonts, the group containing animals, fungi and their closest protist relatives.
Thecamonadinae is a subfamily of heterotrophic protists. It is a monophyletic group, or clade, of apusomonads, a group of protozoa with two flagella closely related to the eukaryotic supergroup Opisthokonta. The subfamily contains two genera Chelonemonas and Thecamonas, which are found in marine habitats.