| 释义 |
Definition of Acanthocephala in English: Acanthocephalaplural noun əˌkanθə(ʊ)ˈsɛfələəˌkanθə(ʊ)ˈkɛfələəˌkanTHōˈsefələ Zoology A small phylum of parasitic invertebrates that comprises the thorny-headed worms. Example sentencesExamples - Limnognathia maerski has dorsal plates formed by an intracellular matrix, as in Rotifera and Acanthocephala, but ventrally the epidermis is ‘naked’ only with a thin glycocalyx.
- Significant amounts of character loss versus character innovation is expected if the evolution of parasitism in Acanthocephala is truly ‘degenerative.’
- Because the new taxon lacks syncytia, a key character for the Rotifera and Acanthocephala, the Micrognathozoa cannot be included in Syndermata.
- The dotted line with a question mark denotes the suggestion of Ahlrichs that Acanthocephala and Seisonida are sister groups.
- Rotifera and Acanthocephala comprise a monophyletic group with high bootstrap pseudoreplicate recovery and decay score.
- Also, within Acanthocephala there have been multiple shifts between aquatic and terrestrial intermediate and definitive hosts.
- The 18S rRNA inferred phylogeny provides a framework to investigate the evolutionary diversification of features associated with parasitism in Acanthocephala.
- Like the Acanthocephala, they are probably evil rotifers.
- Nielsen and Nielsen et al. come to generally comparable results, although sometimes the additional taxa Rotifera, Acanthocephala and Chaetognatha were included in Aschelminthes.
- The sister - group relationship between Gnathostomulida and Rotifera + Acanthocephala was first mentioned by Rieger and Tyler.
- Perversely, they failed to include any sequences from rotifers, gnathostomulids, chaetognaths, or, in fact, anything that might actually be comparable to Acanthocephala.
- However, our molecular data show they may be related to Rotifers + Acanthocephala inside the taxon Gnathifera.
- The remaining members of this novel metazoan clade were Rotifera, Acanthocephala (together Syndermata), and Cycliophora.
- Micrognathozoa lack this characteristic feature and, therefore, are postulated to be more basal in the Gnathifera, as a sister-group either to Gnathostomulida or Rotifera / Acanthocephala.
- The shift between aquatic and terrestrial hosts in Acanthocephala is probably driven by availability of appropriate arthropod intermediate hosts in the particular habitat.
- An earlier study using morphological evidence hypothesized that Acanthocephala is the sister taxon of the rotifer class Bdelloidea, making Rotifera paraphyletic.
- However, the relationship between Rotifera and Acanthocephala has not been resolved.
- Although the ICL has little taxonomic significance, it is synapomorphic with phylum Acanthocephala, indicating a close phylogenetic relationship.
- Traditionally, the taxonomic groups in Acanthocephala have been identified based on morphological features and host characteristics.
Derivatives adjective & noun Zoology Parsimony analyses recover a paraphyletic Rotifera, where a bdelloid rotifer and acanthocephalans form a monophyletic clade. Example sentencesExamples - Alewives caught off the Atlantic coast were found to host the following parasites: acanthocephalans, cestode, trematodes, copepods, and nematodes.
- Maximum-parsimony and maximum-likelihood inferred trees differ significantly with regard to relationships among acanthocephalans and rotifers.
- However, among helminth parasites, e.g., trematodes, cestodes, nematodes, and acanthocephalans, this is not the case.
- This constraint may limit acanthocephalan lineages to particular arthropod hosts, whereas the use of particular vertebrate hosts may be more free to vary.
- Guidance and encouragement for my research involving acanthocephalans has been provided by Steven A. Nadler.
- Third, substantial phylogenetic evidence from both morphology and molecular data indicates that acanthocephalans have a close evolutionary relationship with Rotifera.
- Other animals with a pseudocoel, such as rotifers and acanthocephalans, appear to be more closely related to Lophotrochozoa, a large alliance of protostomes that includes molluscs, annelids, brachiopods, etc.
- For example, in some morphologically based studies the issue is whether the lemnisci and proboscis of acanthocephalans are homologous to the hypodermic cushions and apical rostrum of bdelloids.
- The acanthocephalan Leptorhynchoides is a parasite of vertebrate carnivores which looks a little like a nemertine worm with training wheels.
- The solution of several apicomplexan, acanthocephalan and trematode parasites to this problem is a particularly efficient yet improbable one.
- Information on 113 trematode, 86 cestode, 13 acanthocephalan, 37 nematode, 5 leech, 12 mite, and 15 lice species is included.
- Challenges-Rotifers appear to be very different from acanthocephalans.
- Many sea otters died from being infected by a parasitic acanthocephalan worm found in sand crabs the sea otters ate when other more natural prey was scarce.
- Unlike the situation in nematodes and platyhelminths, substantial evidence supports a close phylogenetic affinity of acanthocephalans to the predominately free-living rotifers.
- The inferred phylogenetic relationships between acanthocephalans and rotifers differ appreciably.
- In addition, I reexamine the controversy regarding the relationships of acanthocephalans and rotifers using all available 18S rRNA sequences.
- The study of Garey et al., which used two genes (18S rRNA and mt 16S rRNA) and B. plicatilis, yielded a tree in which acanthocephalans cluster as modified bdelloids.
adjective & noun Zoology Numerous acanthocephalids are also attached to the mucosa of the cecum and the cecal-colic junction.
Origin Modern Latin (plural), from acantho- 'thornlike' + Greek kephalē 'head'. Definition of Acanthocephala in US English: Acanthocephalaplural nounəˌkanTHōˈsefələ Zoology A small phylum of parasitic invertebrates that comprises the thorny-headed worms. Example sentencesExamples - Traditionally, the taxonomic groups in Acanthocephala have been identified based on morphological features and host characteristics.
- Nielsen and Nielsen et al. come to generally comparable results, although sometimes the additional taxa Rotifera, Acanthocephala and Chaetognatha were included in Aschelminthes.
- The sister - group relationship between Gnathostomulida and Rotifera + Acanthocephala was first mentioned by Rieger and Tyler.
- Because the new taxon lacks syncytia, a key character for the Rotifera and Acanthocephala, the Micrognathozoa cannot be included in Syndermata.
- However, the relationship between Rotifera and Acanthocephala has not been resolved.
- Like the Acanthocephala, they are probably evil rotifers.
- Also, within Acanthocephala there have been multiple shifts between aquatic and terrestrial intermediate and definitive hosts.
- The dotted line with a question mark denotes the suggestion of Ahlrichs that Acanthocephala and Seisonida are sister groups.
- Although the ICL has little taxonomic significance, it is synapomorphic with phylum Acanthocephala, indicating a close phylogenetic relationship.
- Rotifera and Acanthocephala comprise a monophyletic group with high bootstrap pseudoreplicate recovery and decay score.
- Micrognathozoa lack this characteristic feature and, therefore, are postulated to be more basal in the Gnathifera, as a sister-group either to Gnathostomulida or Rotifera / Acanthocephala.
- Perversely, they failed to include any sequences from rotifers, gnathostomulids, chaetognaths, or, in fact, anything that might actually be comparable to Acanthocephala.
- Limnognathia maerski has dorsal plates formed by an intracellular matrix, as in Rotifera and Acanthocephala, but ventrally the epidermis is ‘naked’ only with a thin glycocalyx.
- The remaining members of this novel metazoan clade were Rotifera, Acanthocephala (together Syndermata), and Cycliophora.
- The 18S rRNA inferred phylogeny provides a framework to investigate the evolutionary diversification of features associated with parasitism in Acanthocephala.
- Significant amounts of character loss versus character innovation is expected if the evolution of parasitism in Acanthocephala is truly ‘degenerative.’
- The shift between aquatic and terrestrial hosts in Acanthocephala is probably driven by availability of appropriate arthropod intermediate hosts in the particular habitat.
- However, our molecular data show they may be related to Rotifers + Acanthocephala inside the taxon Gnathifera.
- An earlier study using morphological evidence hypothesized that Acanthocephala is the sister taxon of the rotifer class Bdelloidea, making Rotifera paraphyletic.
Origin Modern Latin (plural), from acantho- ‘thornlike’ + Greek kephalē ‘head’. |