Euglenozoa
| Euglenozoa | |
|---|---|
| |
| Two Euglena | |
| Scientific classification | |
| Domain: | |
| (unranked): | |
| Phylum: | Euglenozoa Cavalier-Smith, 1981[1]
|
| Classes and unplaced genera | |
| Synonyms | |
| |
The Euglenozoa are a large group of flagellate protozoa. They include a variety of common free-living species, as well as a few important parasites, some of which infect humans. There are two main subgroups, the euglenids and kinetoplastids. Euglenozoa are unicellular, mostly around 15-40 µm in size, although some euglenids get up to 500 µm long.[2]
Structure
Most euglenozoa have two flagella, which are inserted parallel to one another in an apical or subapical pocket. In some these are associated with a cytostome or mouth, used to ingest bacteria or other small organisms. This is supported by one of three sets of microtubules that arise from the flagellar bases; the other two support the dorsal and ventral surfaces of the cell.[3]
Some other euglenozoa feed through absorption, and many euglenids possess chloroplasts and so obtain energy through photosynthesis. These chloroplasts are surrounded by three membranes and contain chlorophylls A and B, along with other pigments, so are probably derived from a captured green alga. Reproduction occurs exclusively through cell division. During mitosis, the nuclear membrane remains intact, and the spindle microtubules form inside of it.[3]
The group is characterized by the ultrastructure of the flagella. In addition to the normal supporting microtubules or axoneme, each contains a rod (called paraxonemal), which has a tubular structure in one flagellum and a latticed structure in the other. Based on this, two smaller groups have been included here: the diplonemids and Postgaardi.[4]
Classification
The euglenozoa are generally accepted as monophyletic. They are related to Percolozoa; the two share mitochondria with disk-shaped cristae, which only occurs in a few other groups.[5] Both probably belong to a larger group of eukaryotes called the excavates.[6] This grouping, though, has been challenged.[7]
Phylogeny
The phylogeny based on the work of Cavalier-Smith 2016.[8]
Taxonomy
Phylum Euglenozoa Cavalier-Smith 1981 emend. Simpson 1997[8] [Euglenobionta]
- Subphylum Postgaardia Cavalier-Smith 2016
- Class Postgaardea Cavalier-Smith 1998 s.s. [Symbiontida Yubuki et al., 2009]
- Order Bihospitida Cavalier-Smith 2016
- Family Bihospitidae Cavalier-Smith 2016
- Order Postgaardida Cavalier-Smith 2003
- Family Calkinsiidae Cavalier-Smith 2016
- Family Postgaardidae Cavalier-Smith 2016
- Order Bihospitida Cavalier-Smith 2016
- Class Postgaardea Cavalier-Smith 1998 s.s. [Symbiontida Yubuki et al., 2009]
- Subphylum Glycomonada Cavalier-Smith 2016
- Class Diplonemea Cavalier-Smith 1993 emend. Simpson 1997 [Diplosonematea; Diplonemia Cavalier-Smith 1993]
- Order Diplonemida Cavalier-Smith 1993 [Hemistasiida]
- Family Hemistasiidae Cavalier-Smith 2016 [Entomosigmaceae]
- Family Diplonemidae Cavalier-Smith 1993 [Rhynchopodaceae]
- Order Diplonemida Cavalier-Smith 1993 [Hemistasiida]
- Class Kinetoplastea Honigberg 1963 emend. Margulis 1974 [Kinetoplastida Honigberg 1963; Kinetoplasta Honigberg 1963 stat. nov.]
- Order Bordnamonadida
- Family Bordnamonadidae Cavalier-Smith 2013
- Order Trypanophidida
- Family Trypanophididae Poche 1911
- Subclass Prokinetoplastina Vickerman 2004
- Order Prokinetoplastida Vickerman 2004
- Family Ichthyobodonidae Isaksen et al., 2007
- Order Prokinetoplastida Vickerman 2004
- Subclass Metakinetoplastina Vickerman 2004
- Order Neobodonida Vickerman 2004
- Family Rhynchomonadidae Cavalier-Smith 2016
- Family Neobodonidae Cavalier-Smith 2016
- Order Parabodonida Vickerman 2004
- Family Parabodonidae Cavalier-Smith 2016 [Cryptobiaceae Poche 1911; Trypanoplasmatidae Hartmann & Chagas 1910]
- Order Bodonida Hollande 1952 emend. Vickerman 1976 [Eubodonida Vickerman 2004]
- Family Bodonidae Bütschli 1883 [Bodonaceae]
- Order Trypanosomatida Kent 1880 stat. n. Hollande, 1952 emend. Vickerman 2004
- Family Trypanosomatidae Doflein 1901
- Order Neobodonida Vickerman 2004
- Order Bordnamonadida
- Class Diplonemea Cavalier-Smith 1993 emend. Simpson 1997 [Diplosonematea; Diplonemia Cavalier-Smith 1993]
- Subphylum Euglenoida Bütschli 1884 emend. Senn 1900 stat. nov. Cavalier-Smith, 1993 [Euglenophyta; Euglenida Buetschli 1884; Euglenoidina Buetschli 1884]
- Infraphylum Entosiphona Cavalier-Smith 2016
- Class Entosiphonea Cavalier-Smith 2016
- Order Entosiphonida Cavalier-Smith 2016
- Family Entosiphonidae Cavalier-Smith 2016
- Order Entosiphonida Cavalier-Smith 2016
- Class Entosiphonea Cavalier-Smith 2016
- Infraphylum Dipilida Cavalier-Smith 2016
- Class Stavomonadea Cavalier-Smith 2016
- Subclass Heterostavia Cavalier-Smith 2016
- Order Heterostavida Cavalier-Smith 2016
- Family Serpenomonadidae Cavalier-Smith 2016
- Order Heterostavida Cavalier-Smith 2016
- Subclass Homostavia Cavalier-Smith 2016
- Order Decastavida Cavalier-Smith 2016a
- Family Decastavidae Cavalier-Smith 2016a
- Family Keelungiidae Cavalier-Smith 2016a
- Order Petalomonadida Cavalier-Smith 1993
- Family Sphenomonadidae Kent 1880 [Sphenomonadales Leedale 1967; Sphenomonadina Leedale 1967]
- Family Petalomonadidae [Petalomonadaceae Buetschli 1884; Notosolenaceae Stokes 1888; Scytomonadaceae Ritter von Stein 1878; Petalomonadea Cavalier-Smith 1993; Petalomonadophyceae]
- Order Decastavida Cavalier-Smith 2016a
- Subclass Heterostavia Cavalier-Smith 2016
- Class Ploeotarea Cavalier-Smith 2016
- Order Ploeotiida Cavalier-Smith 1993
- Family Lentomonadidae Cavalier-Smith 2016
- Family Ploeotiidae Cavalier-Smith 2016
- Order Ploeotiida Cavalier-Smith 1993
- Superclass Spirocuta Cavalier-Smith 2016
- Class Peranemea Cavalier-Smith 1993 emend. Cavalier-Smith 2016
- Subclass Acroglissia Cavalier-Smith 2016
- Order Acroglissida Cavalier-Smith 2016
- Family Teloproctidae Cavalier-Smith 2016a
- Order Acroglissida Cavalier-Smith 2016
- Subclass Peranemia Cavalier-Smith 2016
- Order Peranemida Bütschli 1884 stat. nov. Cavalier-Smith 1993
- Family Peranematidae [Peranemataceae Dujardin 1841; Pseudoperanemataceae Christen 1962]
- Order Peranemida Bütschli 1884 stat. nov. Cavalier-Smith 1993
- Subclass Anisonemia Cavalier-Smith 2016
- Order Anisonemida Cavalier-Smith 2016 [Heteronematales Leedale 1967]
- Family Anisonemidae Saville Kent, 1880 em. Cavalier-Smith 2016 [Heteronemidae; Zygoselmidaceae Kent 188]
- Order Natomonadida Cavalier-Smith 2016
- Suborder Metanemina Cavalier-Smith 2016
- Family Neometanemidae Cavalier-Smith 2016
- Suborder Rhabdomonadina Leedale 1967 emend. Cavalier-Smith 1993 [Astasida Ehrenberg 1831; Rhabdomonadia Cavalier-Smith 1993; Rhabdomonadophyceae; Rhabdomonadales]
- Family Distigmidae Hollande, 1942
- Family Astasiidae Saville Kent, 1884 [Rhabdomonadaceae Fott 1971; Menoidiaceae Buetschli 188; Menoidiidae Hollande, 1942; Rhabdomonadidae]
- Suborder Metanemina Cavalier-Smith 2016
- Order Anisonemida Cavalier-Smith 2016 [Heteronematales Leedale 1967]
- Subclass Acroglissia Cavalier-Smith 2016
- Class Euglenophyceae Schoenichen 1925 emend. Marin & Melkonian 2003 [Euglenea Bütschli 1884 emend. Busse & Preisfeld 2002; Euglenoidea Bütschli 1884; Euglenida Bütschli 1884] (Photosynthetic clade)
- Subclass Rapazia Cavalier-Smith 2016
- Subclass Euglenophycidae Busse and Preisfeld, 2003
- Order Eutreptiida [Eutreptiales Leedale 1967 emend. Marin & Melkonian 2003; Eutreptiina Leedale 1967]
- Family Eutreptiaceae [Eutreptiaceae Hollande 1942]
- Order Euglenida Ritter von Stein, 1878 stat. n. Calkins, 1926 [Euglenales Engler 1898 emend. Marin & Melkonian 2003; Euglenina Buetschli 1884; Euglenomorphales Leedale 1967; Colaciales]
- Family Euglenamorphidae Hollande, 1952 stat. n. Cavalier-Smith 2016 [Euglenomorphaceae; Hegneriaceae Brumpt & Lavier 1924]
- Family Phacidae [Phacaceae Kim et al. 2010]
- Family Euglenidae [Euglenaceae Dujardin 1841 emend. Kim et al. 2010] (Mucilagenous clade)
- Order Eutreptiida [Eutreptiales Leedale 1967 emend. Marin & Melkonian 2003; Eutreptiina Leedale 1967]
- Class Peranemea Cavalier-Smith 1993 emend. Cavalier-Smith 2016
- Class Stavomonadea Cavalier-Smith 2016
- Infraphylum Entosiphona Cavalier-Smith 2016
References
- ^ T. Cavalier-Smith (1981). "Eukaryote Kingdoms: Seven or Nine?". BioSystems. 14 (3–4): 461–481. doi:10.1016/0303-2647(81)90050-2. PMID 7337818.
- ^ "Euglenozoa". Retrieved 21 May 2013.
- ^ a b David J. Patterson (1999). "The Diversity of Eukaryotes". American Naturalist. 154 (S4): S96–S124. doi:10.1086/303287. PMID 10527921.
- ^ Alastair G. B. Simpson (1997). "The Identity and Composition of Euglenozoa". Archiv für Protistenkunde. 148: 318–328. doi:10.1016/s0003-9365(97)80012-7.
- ^ Baldauf, S. L.; Roger, A. J.; Wenk-Siefert, I.; Doolittle, W. Ford (2000). "A Kingdom-Level Phylogeny of Eukaryotes Based on Combined Protein Data". Science. 290 (5493): 972–977. doi:10.1126/science.290.5493.972. PMID 11062127.
- ^ Alastair G. Simpson (2003). "Cytoskeletal organization, phylogenetic affinities and systematics in the contentious taxon Excavata (Eukaryota)". International Journal of Systematic and Evolutionary Microbiology. 53 (Pt 6): 1759–1777. doi:10.1099/ijs.0.02578-0. PMID 14657103.
- ^ Cavalier-Smith T (December 2009). "Kingdoms Protozoa and Chromista and the eozoan root of the eukaryotic tree". Biol Lett. 6 (3): 342–5. doi:10.1098/rsbl.2009.0948. PMC 2880060. PMID 20031978.
- ^ a b Thomas Cavalier-Smith (2016). "Higher Classification and Phylogeny of Euglenozoa". European Journal of Protistology. doi:10.1016/j.ejop.2016.09.003.
{{cite web}}:|access-date=requires|url=(help); Missing or empty|url=(help)