Enoplea

Enoplea
Mermis nigrescens
Scientific classification
Kingdom: Animalia
Phylum: Nematoda
Class: Enoplea
Inglis, 1983
Subclasses

Enoplea (enopleans) is a class within the phylum Nematoda.[1][2][3]

Description

The Enoplea are distinguished from the Chromadorea by a number of characteristics. The enoplean esophagus is cylindrical or "bottle-shaped", compared to the bulbous chromadorean esophagus. Enopleans have pocket-like amphids, while chromadoreans have amphids shaped like slits, pores, coils, or spirals. An enoplean is smooth or marked with fine lines, while a chromadorean may have rings, projections, or setae. The enoplean excretory system is simple, sometimes made up of a single cell, while chromadoreans have more complex, tubular systems, sometimes with glands.[4][5]

Taxonomy

Phylogenetic analysis of phylum Nematoda suggests three distinct basal clades, the dorylaims, enoplids and chromadorids.[6] These represent Clades I, II and C+S of Blaxter (1998).[7] Of these, the first two appear to have sister clade status, allowing resolution into two classes, Enoplea and Chromadorea, and division of the former into two subclasses corresponding to Clades I and II respectively, the Enoplia and Dorylaimia.

However, some researchers have contested this hypothesis, finding instead support for Dorylaimia and Chromadoria being sister groups while Enoplia is sister to all other nematodes, making Enoplea paraphyletic.[8][9] The classification proposed by Hodda (2022) removes Dorylaimia from Enoplea, making it a separate class,[10] as shown below.

Subdivision

Two subclasses are divided into orders.[4][6][11]

Classification proposed by Hodda (2022)

Class Dorylaimea

  • Subclass Dorylaimia
  • Subclass Bathyodontia
  • Subclass Trichocephalia

Class Enoplea

  • Subclass Enoplia
    • Superorder Enoplica
    • Superorder Rhaptothyreica
      • Order Rhaptothyreida
  • Subclass Oncholaimia
  • Subclass Triplonchia

Ecology

Several orders of enopleans are mainly freshwater animals, and several include marine species.[12]

Many enopleans are parasites of plants and animals, including humans. The orders Triplonchida and Dorylaimida include plant-parasitic nematodes that are vectors of plant pathogens. The orders Mermithida and Marimermithida include parasites of invertebrates. The orders Dioctophymatida, Trichinellida, and Muspiceida include parasites of vertebrates such as birds and mammals. Examples are Trichinella spiralis, a nematode known for causing trichinosis in humans who consume it in undercooked pork, Haycocknema perplexum which can be life-threatening to humans,[13] and whipworms (genus Trichuris), which are parasites of mammals, including cats, dogs, and humans.[4]

References

  1. ^ Phylum Nematoda. Archived 2013-10-12 at the Wayback Machine Nemaplex: Nematode-Plant Expert Information System. University of California, Davis. Version October 4, 2012.
  2. ^ Jühling, F.; et al. (2012). "Armless mitochondrial tRNAs in Enoplea (Nematoda)". RNA Biology. 9 (9): 1161–66. doi:10.4161/rna.21630. PMC 3579883. PMID 23018779.
  3. ^ Hyman, B. C.; et al. (2011). "Rampant gene rearrangement and haplotype hypervariation among nematode mitochondrial genomes". Genetica. 139 (5): 611–15. doi:10.1007/s10709-010-9531-3. PMC 3089818. PMID 21136141.
  4. ^ a b c Class Enoplea. Archived 2013-09-28 at the Wayback Machine Nemaplex: Nematode-Plant Expert Information System. University of California, Davis. Version October 9, 2012.
  5. ^ Class Chromadorea. Archived 2013-12-31 at the Wayback Machine Nemaplex: Nematode-Plant Expert Information System. University of California, Davis. Version October 4, 2012.
  6. ^ a b Lee 2010, p. 13.
  7. ^ Blaxter 1998.
  8. ^ Smythe, Ashleigh B.; Holovachov, Oleksandr; Kocot, Kevin M. (2019). "Improved phylogenomic sampling of free-living nematodes enhances resolution of higher-level nematode phylogeny". BMC Evolutionary Biology. 19 (1). doi:10.1186/s12862-019-1444-x. ISSN 1471-2148. PMC 6567515. PMID 31195978.
  9. ^ Ahmed, Mohammed; Roberts, Nickellaus G.; Adediran, Funmilola; Smythe, Ashleigh B.; Kocot, Kevin M.; Holovachov, Oleksandr (2022-01-28). "Phylogenomic Analysis of the Phylum Nematoda: Conflicts and Congruences With Morphology, 18S rRNA, and Mitogenomes". Frontiers in Ecology and Evolution. 9. doi:10.3389/fevo.2021.769565. ISSN 2296-701X.
  10. ^ Hodda, M. (2022-03-10). "Phylum Nematoda: a classification, catalogue and index of valid genera, with a census of valid species". Zootaxa. 5114 (1): 1–289. doi:10.11646/zootaxa.5114.1.1. ISSN 1175-5334.
  11. ^ Zhang 2011, p. 63.
  12. ^ Tahseen, Q (2012). "Nematodes in aquatic environments: adaptations and survival strategies" (PDF). Biodiversity Journal. 3 (1): 13–40.
  13. ^ Basuroy, Ron; Pennisi, Robert (February 2008). "Parasitic myositis in tropical Australia". Medical Journal of Australia. 188 (4): 254–256. doi:10.5694/j.1326-5377.2008.tb01601.x. PMID 18279140. S2CID 44551136. Retrieved 10 December 2017.

Bibliography