Nausithoidae
Nausithoe aurea
The Nausithoidae are a family of screen Jellyfish ( Scyphozoa ). Currently, about 26 species are known to live mostly in deeper waters.
Features
The family includes both metagenetic genres as well as a genus (yet ) forms only a polyp stage. The polyps sit in sleek Peridermröhren of chitin and can produce by strobilation Ephyralarven, which develop into medusae on, but also Planuloide (or planulalarven - like structures ), which only grow again polyps. The medusae have eight Rhopalia, eight tentacles, 16 randliche cloth and 16 radial stomach bags. The medusae are usually relatively small ( 9-35 mm).
Geographical occurrence
The species of the family are found worldwide. Most species occur at greater depths. Nausithoe werneri Jarms, 1990 comes, for example, at depths of 200 to 3000 m depth before. In contrast Thecoscyphus zibrowii has only been found in the caves at 5 and 15 m water depth.
System
Currently, the family Nausithoidae be assigned three genera:
- Nausithoe Kölliker, 1853
- Palephyra Haeckel, 1880, and
- Thecoscyphus Werner, 1984, with: Thecoscyphus zibrowii Werner, 1984.
After the first molecular genetic studies, the Nausithoidae but are probably polyphyletic.