Ichthyosporea

Source: Wikipedia, the free encyclopedia.

Ichthyosporea
Temporal range: Ediacaran–recent
"Sphaeroforma arctica"
Sphaeroforma arctica
Scientific classification Edit this classification
Domain: Eukaryota
Clade: Amorphea
Clade: Obazoa
(unranked): Opisthokonta
(unranked): Holozoa
Class: Ichthyosporea
Cavalier-Smith, 1998[1]
Orders
Synonyms

Mesomycetozoa Mendoza et al., 2002

The Ichthyosporea (or DRIP

parasites
of fish and other animals.

Significance

They are not particularly distinctive morphologically, appearing in host tissues as enlarged spheres or ovals containing spores, and most were originally classified in various groups as fungi, protozoa, or colorless algae. However, they form a coherent group on molecular trees, closely related to both animals and fungi and so of interest to biologists studying their origins. In a 2008 study they emerge robustly as the sibling-group of the clade Filozoa, which includes the animals.[2][3]

Huldtgren et al., following

x-ray tomography of microfossils of the Ediacaran Doushantuo Formation, has interpreted them as mesomycetozoan spore capsules.[4]

Terminology

The name DRIP is an acronym for the first protozoa identified as members of the group,[5] Cavalier-Smith later treated them as the class Ichthyosporea, since they were all parasites of fish.

Since other new members have been added (e.g. the former fungal orders

Amoebidiales), Mendoza et al. suggested changing the name to Mesomycetozoea, which refers to their evolutionary position. On Eukaryota tree, in Opisthokont clade, Mesomycetozoea is in the middle ("Meso-") of the fungi ("-myceto-") and the animals ("-zoea").[6] Note the name Mesomycetozoa (without a third e) is also used to refer to this group, but Mendoza et al. use it as an alternate name for basal Opisthokonts.[7]

Phylogeny

Eukaryota tree. Note "Ichthyosporea" at bottom left, in Opisthokont clade. "Metazoa" are animals, and Choanoflagellates are closely aligned. Fungi is at other end of Opisthokont clade, with Cristidiscoidea closely aligned. Ichthyosporea is in the middle ("Meso-") of the fungi ("-myceto-") and the animals ("-zoea").
Ichthyosporea[8][9]
Dermocystida

Dermocystidaceae

Ichthyophonida

Creolimacidae

Psorospermidae

Piridae

Trichomycina

Amoebidiidae

Ichthyophonidae

Paramoebidiidae

Eccrinida

Parataeniellaceae

Eccrinaceae

Taxonomy

  • Class Ichthyosporea Cavalier-Smith 1998[10][11]
    • Order Dermocystida Cavalier-Smith 1998
      • Family Rhinosporidiaceae Mendoza et al. 2001
    • Order Ichthyophonida Cavalier-Smith 1998
      • Suborder Sphaeroformina Cavalier-Smith 2012
        • Family Creolimacidae Cavalier-Smith 2012
        • Family Psorospermidae Cavalier-Smith 2012
        • Family Piridae Cavalier-Smith 2012
      • Suborder Trichomycina Cavalier-Smith 2012
        • Genus †Paleocadus Poinar 2016
        • Family Amoebidiidae Lichtenstein 1917 ex Kirk et al. 2001
        • Family Ichthyophonidae Cavalier-Smith 2012
        • Family Paramoebidiidae Reynolds et al. 2017
        • Family Parataeniellaceae Manier & Lichtward 1968
        • Family Eccrinaceae Leger & Duboscq 1929 [Palavasciaceae Manier & Lichtward 1968]

References

  1. ^ Cavalier-Smith, T. 1998. Neomonada and the origin of animals and fungi. In: Coombs GH, Vickerman K, Sleigh MA, Warren A (ed.) Evolutionary relationships among protozoa. Kluwer, London, pp. 375-407,
  2. PMID 18461162
    .
  3. ISBN 978-0544859937
    .
  4. ^ Douglas Fox, "How life got complicated", Discover Magazine, December 2012.
  5. PMID 8876236
    .
  6. PMID 10449446
    .
  7. PMID 12142489
    .
  8. S2CID 52977120
    .
  9. PMID 28219758
    .
  10. PMID 23085100
    .
  11. doi:10.1017/S0953756204221554
    .
Retrieved from "https://en.wikipedia.org/w/index.php?title=Ichthyosporea&oldid=1198007050"