Kinorhyncha
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| Kinorhynchs | ||||
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Order Cyclorhagida
Order Homalorhagida
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Kinorhyncha (Gr. kīneō 'move' + 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.
[edit] External links
ca:Quinorrinc cs:Rypečky da:Mudderdrage de:Hakenrüssler et:Siilussid es:Kinorhyncha fr:Kinorhyncha gl:Kinorhyncha it:Kinorhyncha la:Cinorhyncha ja:動吻動物 oc:Kinorhyncha pl:Ryjkogłowy pt:Kinorhyncha ru:Киноринхи sr:Kinorhyncha fi:Okapäämadot sv:Pansarmaskar tr:Derisi dikenli solucanlar zh:动吻动物门
