Difflugia

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Difflugia
Critique of the Theory of Evolution Fig 092.jpg
Races of Difflugia. (After Leidy.)
Scientific classification
Domain: Eukaryota
(unranked): Amoebozoa
Class: Tubulinea
Order: Arcellinida
Suborder: Difflugina
Family: Difflugiidae
Genus: Difflugia
Leclerc, 1815

Difflugia is the largest genus of Arcellinida, one of several groups of Tubulinea within the eukaryote supergroup Amoebozoa.[1] Arcellinida species produce shells or tests from mineral particles or biogeonic elements (e.g. diatom frustules) and are thus commonly referred to as testate amoebae or shelled amoebae. Difflugia are particularly common in marshes and other freshwater habitats.

The particles used to build the shell are collected by the amoeba directly from the environment, or from their prey. During cell division they pass into the daughter cell, where they are assembled in shape and joined by a sheet-like organic cement.[2] The test has a single terminal opening (the pseudostome). The shape of the shell ranges from spherical to elongated, sometimes with ornamentation such as horns or a collar,[3] sometimes both, as in Difflugia corona.[4]

Difflugia use pseudopods to move around and capture their prey as do other amoeboid protists. Most species of Difflugia are heterotrophs, feeding on organic matter or various prey organisms. Some species however contain endo-symbiotic algae and are therefore mixotrophic, i.e. combining autotrophy and heterotrophy,.[5][6]

Molecular phylogenetic studies suggest that the genus Difflugia is not monophyletic. The definition of the genus is problematic and future research will most likely result in major taxonomic revision of this group.[3]

References[edit]

  1. ^ Adl SM, Simpson AG, Lane CE, Lukeš J, Bass D, Bowser SS, Brown MW, Burki F, Dunthorn M, Hampl V, Heiss A, Hoppenrath M, Lara E, le Gall L, Lynn DH, McManus H, Mitchell EA, Mozley-Stanridge SE, Parfrey LW, Pawlowski J, Rueckert S, Shadwick L, Schoch CL, Smirnov A, Spiegel FW (2012). "The Revised Classification of Eukaryotes". Journal of Eukaryotic Microbiology. 59: 429–514. doi:10.1111/j.1550-7408.2012.00644.x. PMC 3483872free to read. PMID 23020233. 
  2. ^ Ralf Meisterfeld: Arcellinida, In: John J. Lee, Gordon F. Leedale, Phyllis Bradbury (Hrsg.): The Illustrated Guide to the Protozoa, 2nd Edition. Vol. 2, Society of Protozoologists, Lawrence, Kansas 2000, ISBN 1-891276-23-9, pp. 827-860
  3. ^ a b Gomaa F, Todorov M, Heger TJ, Mitchell EA, Lara E (2012). "SSU rRNA Phylogeny of Arcellinida (Amoebozoa) Reveals that the Largest Arcellinid Genus, Difflugia Leclerc 1815, is not Monophyletic". Protist. 163: 389–99. doi:10.1016/j.protis.2011.12.001. 
  4. ^ Silva-Briano M, Martínez-Hernández SL, Adabache-Ortíz A, Ventura-Juárez J, Salinas E, Quintanar JL (August 2007). "Ultrastructural analysis and identification of membrane proteins in the free-living amoeba Difflugia corona". Biocell. 31 (2): 225–8. PMID 17902270. 
  5. ^ Ralf Meisterfeld: Arcellinida, In: John J. Lee, Gordon F. Leedale, Phyllis Bradbury (Hrsg.): Illustrated Guide to the Protozoa, 2nd Edition. Vol. 2, Society of Protozoologists, Lawrence, Kansas 2000, ISBN 1-891276-23-9, pp. 827-860
  6. ^ Schönborn W (1965). "Untersuchungen über die Zoochlorellen-Symbiose der Hochmoor-Testaceen". Limnologica. 3: 173–176. 

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