Labyrinthulomycetes

Labyrinthulomycetes
The cell with the network of filaments Aplanochytrium sp.
Scientific classification
Domain: Eukaryota
Kingdom: Chromalveolata
Phylum: Heterokontophyta
Class: Labyrinthulomycetes Arx, 1970,
Dick, 2001, or
Labyrinthulea Olive, 1975
ex Cavalier-Smith, 1989
Genera

Labyrinthulids
Labyrinthula
Thraustochytrids
Aplanochytrium
Labyrinthuloides
Japonochytrium
Schizochytrium
Thraustochytrium
Ulkenia
Diplophryids
Diplophrys

Synonyms
  • Labyrinthulomycota Whittaker, 1969
  • Labyrinthomorpha Page in Levine et al., 1980

The Labyrinthulomycetes (ICBN) or Labyrinthulea[1] (ICZN), are a class of protists that produce a network of filaments or tubes,[2] which serve as tracks for the cells to glide along and absorb nutrients for them. There are two main groups, the labyrinthulids (or slime nets) and thraustochytrids. They are mostly marine, commonly found as parasites on alga and seagrass or as decomposers on dead plant material. They also include some parasites of marine invertebrates.[3]

Although they are outside the cells, the filaments are surrounded by a membrane. They are formed and connected with the cytoplasm by a unique organelle called a sagenogen or bothrosome. The cells are uninucleate and typically ovoid, and move back and forth along the amorphous network at speeds varying from 5-150 μm per minute. Among the labyrinthulids the cells are enclosed within the tubes, and among the thraustochytrids they are attached to their sides.

Classification

Further information: Wikispecies:Labyrinthulomycetes

Labyrinthulomycetes/Labyrinthulea used to belong to the defunct fungal phylum Labyrinthulomycota. They were originally considered unusual slime moulds, although they are not very similar to the other sorts. The structure of their zoospores and genetic studies show them to be a primitive group of heterokonts, but their classification and treatment remains somewhat unsettled.

This class has usually two orders, Labyrinthulales and Thraustochytriales (ICBN), or Labyrinthulida and Thraustochytrida (ICZN).[4]

References

  1. ↑ Cavalier-Smith, T. (1997). "Sagenista and bigyra, two phyla of heterotrophic heterokont chromists". Archiv für Protistenkunde 148 (3): 253–267. doi:10.1016/S0003-9365(97)80006-1.
  2. ↑ Tsui CK, Marshall W, Yokoyama R et al. (January 2009). "Labyrinthulomycetes phylogeny and its implications for the evolutionary loss of chloroplasts and gain of ectoplasmic gliding". Mol. Phylogenet. Evol. 50 (1): 129–40. doi:10.1016/j.ympev.2008.09.027. PMID 18977305.
  3. ↑ Schärer, L.; Knoflach, D.; Vizoso, D. B.; Rieger, G.; Peintner, U. (2007). "Thraustochytrids as novel parasitic protists of marine free-living flatworms: Thraustochytrium caudivorum sp. nov. Parasitizes Macrostomum lignano". Marine Biology 152 (5): 1095. doi:10.1007/s00227-007-0755-4.
  4. ↑ "www.ncbi.nlm.nih.gov". Retrieved 2009-04-04.

External links