Biology:Onychopoda
Onychopoda, from Ancient Greek ὄνυχος (ónukhos), meaning "claw", and πούς poús, meaning "foot", are a specialised order of branchiopod crustaceans, belonging to the superorder Cladocera.
The order Onychopoda is "one of the most morphologically distinctive groups of cladocerans".[1] They have only four pairs of legs, compared to five or six pairs in Ctenopoda and Anomopoda.[2] Unusually among branchiopod crustaceans, Onychopoda share with Haplopoda the presence of segmented appendages, which are used for grasping prey.[3]
Most species of Onychopoda live in the waters of the Ponto-Caspian basin (Caspian Sea, Aral Sea, Black Sea including Sea of Azov), in remnants of the ancient Paratethys ocean.[4] Some other species live in fresh water or in the oceans, where they can be widespread.[4] The Onychopoda have accidentally been introduced to areas outside of their native range.[5]
There are three families, containing 10 genera and around 33 described species, most of which are endemic to the Ponto-Caspian basin:[1]
- Cercopagididae Mordukhai-Boltovskoi, 1968 – 2 genera (Cercopagis and Bythotrephes), 14 species; Black Sea & Caspian Sea
- Podonidae Mordukhai-Boltovskoi, 1968 – 7 genera, 17 species; Pont-Caspian (Caspievadne, Cornigerius and Podonevadne) and marine (Evadne, Pleopis, Podon and Pseudevadne)
- Polyphemidae Baird, 1845 – 1 genus (Polyphemus), 2 species; fresh water
The embryos are protected by a brood pouch, which also secretes nutrients to aid their development. This may be related to the colonisation of the oceans, since the only other marine cladoceran, Penilia avirostris, has a similar pouch as a result of convergent evolution.[1]
See also
References
- ↑ 1.0 1.1 1.2 M. E. A. Cristescu; P. D. N. Hebert (2002). "Phylogeny and adaptive radiation in the Onychopoda (Crustacea, Cladocera): evidence from multiple gene sequences". Journal of Evolutionary Biology 15 (5): 838–849. doi:10.1046/j.1420-9101.2002.00466.x. http://www.bioinfo.uqam.ca/bif7001/articles/BIF7001-Phylo-JEB15.pdf. Retrieved 2011-05-20.
- ↑ D. R. Khanna (2004). "Segmentation in arthropods". Biology of Arthropoda. Discovery Publishing House. pp. 316–394. ISBN 978-81-7141-897-8. https://books.google.com/books?id=Hd4OEDo4gbwC&pg=PA351.
- ↑ G. Fryer (1998). "A defence of arthropod polyphyly". Arthropod Relationships. Volume 55 of Systematics Association Series. Springer. pp. 23–34. ISBN 978-0-412-75420-3. https://books.google.com/books?id=Pj-q9eHyIx0C&pg=PA26.
- ↑ 4.0 4.1 Stefan Richter; Anke Braband; Nikolai Aladin; Gerhard Scholtz (2001). "The phylogenetic relationships of "predatory water-fleas" (Cladocera: Onychopoda, Haplopoda) inferred from 12S rDNA". Molecular Phylogenetics and Evolution 19 (1): 105–113. doi:10.1006/mpev.2000.0901. PMID 11286495. Bibcode: 2001MolPE..19..105R.
- ↑ Kotov, Alexey A.; Karabanov, Dmitry P.; Van Damme, Kay (2022-09-09). "Non-Indigenous Cladocera (Crustacea: Branchiopoda): From a Few Notorious Cases to a Potential Global Faunal Mixing in Aquatic Ecosystems". Water 14 (18): 2806. doi:10.3390/w14182806. ISSN 2073-4441. Bibcode: 2022Water..14.2806K.
External links
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Wikispecies has information related to Onychopoda |
- Podon sp. fact sheet - Guide to the marine zooplankton of south eastern Australia
- Evadne sp. fact sheet - Guide to the marine zooplankton of south eastern Australia
Template:Branchiopoda Wikidata ☰ Q2024726 entry
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