Narcomedusae
| Narcomedusae | ||||||||||
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Narcomeduses from the " Art Forms of Nature " by Ernst Haeckel |
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| Systematics | ||||||||||
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| Scientific name | ||||||||||
| Narcomedusae | ||||||||||
| Haeckel , 1879 |
The Narcomedusae are an order of jellyfish-like hydrozoans from the subclass Trachylinae . There are over 60 species that live mainly free-swimming in the high seas. However, some species also live on the seabed in the sand gap system .
features
The umbrella of the Narcomedus is always clearly lobed. The number of lobes is always the same as the number of tentacles that do not sit on the edge of the screen, but a little further up on the top of the screen. The gastric space has no radial canals as in the trachymedusae , but is greatly widened so that it almost reaches the edge of the umbrella, or forms pockets that reach the edge of the umbrella. The families of the Narcomedus can be distinguished by the shape of the gastric pockets. The gonads sit above the gastric space.
Narcomeduses develop from eggs via actinula larvae. In many species, before the metamorphosis of the actinula larvae into medusa , medusae develop on the upper side of the larva, which then live parasitically in a gastric pouch of the mother medusa or on other hydrojellyfish.
Systematics
The systematics given here follows the information in the Hydrozoa Directory .
- Order Narcomedusae
- Family Cuninidae
- Family Solmarisidae
- Family Aeginidae
- Family Tetraplatiidae
Individual evidence
- ^ Peter Schuchert, The Hydrozoa Directory (accessed September 25, 2009)
literature
- Gruner, H.-E., Hannemann, H.-J., Hartwich, G., Kilias, R .: Urania Tierreich, Invertebrates 1 (Protozoa to Echiurida) . Urania-Verlag, ISBN 3332005014
