Apodida
| Apodida | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
Opheodesoma spectabilis at Coconut Island, in Kaneohe Bay, Oahu , Hawai'i |
||||||||||
| Systematics | ||||||||||
|
||||||||||
| Scientific name | ||||||||||
| Apodida | ||||||||||
| Brandt , 1835 |
The Apodida (from the Greek ἀ- a- 'without' [ negative particle ], and πούς pous 'foot') are an order of sea cucumbers . The animals live in all oceans worldwide, mostly in relatively shallow water, in coral reefs or in mangroves , but also in the deep sea . In the Philippines Trench , the species Myriotrochus bruuni , which is only 1.2 centimeters long, was found at a depth of 10,200 meters. Three species of Apodida live in the North Sea , Leptosynapta bergensis , Leptosynapta inhaerens and Leptosynapta minuta . They also include the largest sea cucumber, the 2.5 meter long Synapta maculata .
features
The Apodida are very slender and elongated worm-like, the skin is thin and sensitive. All apodidae lack the ambulacral feet and papillae on the body surface. In German they are therefore also called footless sea cucumbers . They have 15 to 20 simple or pinnate mouth tentacles that they cannot withdraw. They feed by wiping or dabbing the sea floor with their tentacles, ingesting small food particles or swallowing them, like the sea cucumbers of the order Aspidochirotida sand and sediment. There are always no water lungs or breathing tufts, statocysts are well developed. The gas exchange is made possible by the thin skin. Only the ring canal is left of the blood vessel system, radial vessels are missing.
Most of the species are hermaphrodites. Some species take care of the brood and guard the fertilized eggs in the ovary or in the body cavity.
Systematics
There are three families in the order, 32 genera and 269 species.
- Order Apodida
- Family Chiridotidae Östergren, 1898
- Family Myriotrochidae
- Family worm sea cucumbers (Synaptidae) Östergren, 1898
literature
- Volker Storch, Ulrich Welsch: Systematic Zoology . G. Fischer, Stuttgart 1997, ISBN 3-437-25160-0
- Horst Füller u. a .: Urania animal kingdom, invertebrates 2nd 2nd edition. Urania-Verlag, Leipzig 2000, ISBN 3-332-01175-8
- Alexander M. Kerr: Phylogeny of the Apodan Holothurians (Echinodermata) inferred from morphology . Zoological Journal of the Linnean Society (2001) 133: 53-62. doi : 10.1006 / zjls.2000.0279 PDF
Web links
- Integrated Taxonomic Information System Apodida Brandt, 1835
- ↑ Kerr, Alexander M. 2000. Holothuroidea. Sea cucumbers. Version 01 December 2000. in The Tree of Life Web Project