This MedLibrary.org supplementary page on Kinorhyncha is provided directly from the open source Wikipedia as a service to our readers. Please see the note below on authorship of this content, as well as the Wikipedia usage guidelines. To search for other content from our encyclopedia supplement, please use the form below:
Related Sponsors
| Please help improve this article or section by expanding it. Further information might be found on the talk page or at requests for expansion. (January 2007) |
| Kinorhynchs | ||||
|---|---|---|---|---|
| Scientific classification | ||||
|
||||
| Subdivisions | ||||
|
Order Cyclorhagida
Order Homalorhagida
|
Kinorhyncha (Gr. κίνηω, kīneō 'move' + ρυνχος, rhynchos 'snout') is a phylum of small (1 mm or less) marine pseudocoelomate invertebrates that are widespread in mud or sand at all depths as part of the meiobenthos. They are also called mud dragons.
They are segmented, with a body consisting of a head, neck, and a trunk of eleven segments. They do not have external cilia, but instead have a number of spines along the body, plus up to seven circles of spines around the head,[1] which they use for locomotion, withdrawing the head and pushing forward, then holding with the spines while drawing up the body. The spines are part of a cuticle secreted by the epidermis; this is molted several times while growing to adulthood. The head is completely retractable, and is covered by a set of neck plates called placids when retracted.
Kinorhynchs eat diatoms and other things found in the mud.
There are two sexes that look alike, and the larvae are free-living, but little else is known of their reproductive process.
Their closest relatives are thought to be the phyla Loricifera and Priapulida. Together they constitute the Scalidophora.
The two groups of Kinorhynchs are still generally characterized as orders rather than classes, about 150 species are known.
References
- ^ Brusca and Brusca, Invertebrates, pp. 347
External links
Wikipedia content modification information:
- This page was last modified on 23 July 2008, at 19:05.
Wikipedia Authorship and Review
Wikipedia content provided here is not reviewed directly by MedLibrary.org. Wikipedia content is authored by an open community of volunteers and is not produced by or in any way affiliated with MedLibrary.org.
Wikipedia Usage Guidelines
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article on "Kinorhyncha".
The URL for this specific entry is:
All Wikipedia text is available under the terms of the GNU Free Documentation License. (See Copyrights for details). Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc.
