The Chromadorea are a class of the roundworm phylum, Nematoda. They contain a single subclass (Chromadoria) and several orders. With such a redundant arrangement, the Chromadoria are liable to be divided if the orders are found to form several clades, or abandoned if they are found to constitute a single radiation.
Chromadorea | |
---|---|
Anisakid larvae in the body cavity of an Atlantic herring | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Nematoda |
Class: | Chromadorea Inglis, 1983 |
Subclass: | Chromadoria Pearse, 1942 |
Formerly, they were treated as a subclass in the paraphyletic "Adenophorea" assemblage, which has been mostly abandoned by modern authors. It is also suspected that the Chromadorea may not be monophyletic as delimited here; at least the Monhysterida seem to be a distinct and far more ancient lineage than the rest.
Members of this class' bodies usually have annules, their amphids elaborate and spiral, and they all have three esophageal glands. They usually live in marine sediments, although they can live elsewhere. They have a more sophisticated pharynx than most roundworms.
Members of this class can be identified by the presence of eight conserved signature indels (CSIs) exclusively shared by the class.[1] These molecular markers are found in essential proteins such as tRNA (guanine-N(1))-methyltransferase and can serve as a reliable molecular method of distinguishing the Chromadorea from other classes within the phylum Nematoda.[1]
Orders
editProvisionally, the following orders are placed here:
- Araeolaimida
- Ascaridida[2]
- Chromadorida
- Desmodorida
- Desmoscolecida
- Monhysterida[3]
- Rhabditida
- Rhigonematida[2]
Notes
editThe Benthimermithida are also occasionally placed here.
The Ascaridida appear to be nested within Rhabditida.[4]
References
edit- ^ a b Khadka, Bijendra; Chatterjee, Tonuka; Gupta, Bhagwati P.; Gupta, Radhey S. (2019-09-24). "Genomic Analyses Identify Novel Molecular Signatures Specific for the Caenorhabditis and other Nematode Taxa Providing Novel Means for Genetic and Biochemical Studies". Genes. 10 (10): 739. doi:10.3390/genes10100739. ISSN 2073-4425. PMC 6826867. PMID 31554175.
- ^ a b Martina Wijova; Frantisˇek Moravec; Alesˇ Hora'k; Julius Lukes (April 2006). "Evolutionary relationships of Spirurina (Nematoda: Chromadorea:Rhabditida) with special emphasis on dracunculoid nematodes inferred from SSU rRNA gene sequences". Elsevier. Archived from the original on 2018-03-03. Retrieved 2018-10-03.
- ^ "Phylum Nematoda". THE "NEMATODE-PLANT EXPERT INFORMATION SYSTEM" A Virtual Encyclopedia on Soil and Plant Nematodes. November 2017.
- ^ Park, JK; Sultana, T; Lee, SH; Kang, S; Kim, HK; Min, GS; Eom, KS; Nadler, SA (2011). "Monophyly of clade III nematodes is not supported by phylogenetic analysis of complete mitochondrial genome sequences" (PDF). BMC Genomics. 12: 392. doi:10.1186/1471-2164-12-392. PMC 3163570. PMID 21813000.
External links
edit- Tree of Life Web Project (ToL) (2002): Nematoda. Version of 2002-JAN-01. Retrieved 2008-NOV-02.