Amastigomonas

Genus of protozoa with two flagella

Amastigomonas

Amastigomonas Bar is 10 micrometres.
Scientific classification
Domain:	Eukaryota
Class:	Thecomonadea
Order:	Apusomonadida
Family:	Apusomonadidae
Genus:	Amastigomonas de Saedeleer 1931^[1]
Type species
Amastigomonas debruynei de Saedeleer 1931
Species
A. caudata A. debruynei A. marisrubri

Amastigomonas is a genus of protists belonging to a lineage of biciliated zooflagellates known as Apusomonadida.^[2] It was first described in 1931 by Henri de Saedeleer.^[1] The current use of Amastigomonas is as a descriptive archetype, with no phylogenetic or taxonomic implications. The term "Amastigomonas-like" is used to refer to all apusomonads that lack the 'derived' characteristics of Apusomonas.^[3]

Description

Organisms under the name "Amastigomonas" have an oval or oblong cell that can generate pseudopodia from the ventral surface. They lack a mastigophore, a projection of the cell body that contains both basal bodies at its end. Like all Apusomonadida, they have two flagella, and the anterior flagellum is surrounded by a membranous sleeve.^[3]

Current use of the name

Historically, the name Amastigomonas was used for any apusomonad species that had 'primitive' characteristics compared to the more 'derived' characteristics of Apusomonas. Molecular phylogenetic analyses have shown that Apusomonas branches inside Amastigomonas, making this genus paraphyletic. As a result, many species of Amastigomonas have been reassigned to new genera—Thecamonas, Podomonas, Manchomonas, Multimonas,^[4] Chelonemonas,^[5] Catacumbia, Cavaliersmithia, Karpovia, Mylnikovia and Singekia—, and no currently cultured apusomonad matches the original description of Amastigomonas.^[3]

Apusomonadida

	Apusomonas

	Manchomonas

Karpovia

Singekia

	Chelonemonas

	Thecamonas

	Cavaliersmithia

	Catacumbia

Mylnikovia

Multimonas

Podomonas

"Amastigomonas-like" organisms

Species and distribution

Amastigomonas caudata Karpov & Mylnikov 1989 (marine strain, possibly related to Multimonas).^[5]
Amastigomonas debruynei de Saedeleer 1931 (synonymized into Thecamonas trahens Larsen & Patterson, 1990)
Amastigomonas marisrubri Mylnikov & Mylnikova 2012^[6]

References

^ ^a ^b de Saedeleer H (1931). "Niewe of weinig bekende Flagellaten" [New or little known Flagellates]. Natuurwetenschappelijk Tijdschrift (in Dutch). 13: 89–97.
^ Cavalier-Smith T, Chao EE (May 2003). "Phylogeny of choanozoa, apusozoa, and other protozoa and early eukaryote megaevolution". J. Mol. Evol. 56 (5): 540–63. Bibcode:2003JMolE..56..540C. doi:10.1007/s00239-002-2424-z. PMID 12698292. S2CID 30773513.
^ ^a ^b ^c Torruella G, Galindo LJ, Moreira D, Ciobanu M, Heiss AA, Yubuki N, et al. (2022). "Expanding the molecular and morphological diversity of Apusomonadida, a deep-branching group of gliding bacterivorous protists". Journal of Eukaryotic Microbiology. 00: e12956. doi:10.1111/jeu.12956. hdl:2117/404026.
^ Cavalier-Smith T, Chao EE (May 2010). "Phylogeny and Evolution of Apusomonadida (Protozoa: Apusozoa): New Genera and Species". Protist. 161 (4): 549–76. doi:10.1016/j.protis.2010.04.002. PMID 20537943.
^ ^a ^b Heiss AA, Lee WJ, Ishida KI, Simpson AGB (2015). "Cultivation and Characterisation of New Species of Apusomonads (the Sister Group to Opisthokonts), Including Close Relatives of Thecamonas (Chelonemonas n. gen.)". Journal of Eukaryotic Microbiology. 62: 637–649. doi:10.1111/jeu.12220.
^ Mylnikov AP, Mylnikova ZM (2012). "НОВЫЙ ПСЕВДОПОДИАЛЬНЫЙ ЖГУТИКОНОСЕЦ AMASTIGOMONAS MARISRUBRI (APUSOMONADIDA) ИЗ КРАСНОГО МОРЯ" [A NEW PSEUDOPODIAL FLAGELLATE AMASTIGOMONAS MARISRUBRI (APUSOMONADIDA) FROM THE RED SEA]. Зоологический журнал (Zoological Journal) (in Russian). 91 (4): 387–387.