marine animals  |
|
|
|
|
Phoronida (Bartwürmer) Phoronida |
Horseshoe worms live in tropical and subtropical seas. They live in chitin tubes interspersed with foreign bodies, often in association with cylinder roses in sea sediments at depths of up to 400 meters. The name "horseshoe worms" refers to the characteristic, U-shaped curved tentacle apparatus with which the animals filter their food. This tentacle apparatus is called the Lophophore organ (gr. Lophos "hairhead"), the Lophophore is the U-shaped carrier on which the individual tentacles sit. A similarly constructed tentacle ring around the mouth opening is also found in the armpits (brachiopoda) and mosses (Bryozoa), so these two groups were often combined with the horseshoe worms as a large group of lophophorata or tentaculata (wreath feelers). Molecular biology could only partially confirm this kind of relationship hypothesis. Horseshoe worms and caterpillars are sister groups, and various names such as "Brachiozoa" and "Phoronozoa" have been proposed for this taxon. The third traditional "Lophophorata" group, the Moostierchen, seem however not to be closely related to the other two lines. |
|
root  |
Phoronida (Bartwürmer) Phoronida |
class |
|
|