Monas (heterokont)

Monas
Scientific classification
Domain:	Eukaryota
Clade:	Diaphoretickes
Clade:	SAR
Clade:	Stramenopiles
Phylum:	Gyrista
Subphylum:	Ochrophytina
Class:	Chrysophyceae
Order:	Chromulinales
Family:	Chromulinaceae
Genus:	Monas; O.F. Müller, 1773

Monas is a genus of Chrysophyceae, described by Otto Friedrich Müller in 1773 as a group of Infusoria. Throughout time, it represented an aggregate genus.

Taxonomic history

Many organisms were transferred to this genus, and most Monas spp. have later been synonymised with or integrated in other genera. The organisms once affiliated with Monas spp. truly belong to all major eukaryotic lineages (Opisthokonta, Amoebozoa, Rhizaria, Archaeplastida, Stramenopiles, Alveolata, Cryptophyta, Excavata), and even to prokaryotic lineages.^[2]

The genus was also included in other groups, as in Mastigophora or Flagellata. The current practice is the (questionable) synonymous use, based on morphological similarity, of the generic names Monas (mostly used in the east-Asian literature) and Spumella (synonymously used in the European and American literature) as unpigmented biflagellates in Chrysophyceae. However, there is a conflict between the morphological and molecular investigations. The present-day taxon Monas/Spumella is still polyphyletic, comprising at least three to five lineages, and evidence about the identity of the type species of Monas is missing.^[2]

This problem in the circumscription of groups, using the practical morphological (or taxonomic) species concept or the biological species concept (based on the degree of molecular similarity), is also faced in the taxonomy of other microorganisms,^[3] like other flagellates (e.g., Bodo, Cercomonas)^[2] and microalgae (e.g., Chlorococcales).^[4]

References

^ Guiry, M.D. & Guiry, G.M. 2014. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org/search/genus/detail/?genus_id=44073; searched on 13 October 2014.
^ ^a ^b ^c Boenigk, Jens (2008). "The Past and Present Classification Problem with Nanoflagellates Exemplified by the Genus Monas". Protist. 159 (2): 319–337. doi:10.1016/j.protis.2008.01.001. PMID 18321779.
^ Lahr, D. J.; Laughinghouse, H. D.; Oliverio, A. M.; Gao, F.; Katz, L. A. (2014). "How discordant morphological and molecular evolution among microorganisms can revise our notions of biodiversity on Earth". BioEssays. 36 (10): 950–959. doi:10.1002/bies.201400056. PMC 4288574. PMID 25156897.
^ Krienitz, Lothar; Bock, Christina (2012). "Present state of the systematics of planktonic coccoid green algae of inland waters" (PDF). Hydrobiologia. 698 (1): 295–326. doi:10.1007/s10750-012-1079-z.

[1] Guiry, M.D. & Guiry, G.M. 2014. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org/search/genus/detail/?genus_id=44073; searched on 13 October 2014.

[Boenigk2008-2] Boenigk, Jens (2008). "The Past and Present Classification Problem with Nanoflagellates Exemplified by the Genus Monas". Protist. 159 (2): 319–337. doi:10.1016/j.protis.2008.01.001. PMID 18321779.

[3] Lahr, D. J.; Laughinghouse, H. D.; Oliverio, A. M.; Gao, F.; Katz, L. A. (2014). "How discordant morphological and molecular evolution among microorganisms can revise our notions of biodiversity on Earth". BioEssays. 36 (10): 950–959. doi:10.1002/bies.201400056. PMC 4288574. PMID 25156897.

[Krienitz&Bock2012-4] Krienitz, Lothar; Bock, Christina (2012). "Present state of the systematics of planktonic coccoid green algae of inland waters" (PDF). Hydrobiologia. 698 (1): 295–326. doi:10.1007/s10750-012-1079-z.

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