Trachymedusae
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| Haeckel , 1866 (1879) |
The Trachymedusae are an order of jellyfish-like hydrozoans from the subclass Trachylinae . They contain over 50 species , can have a screen diameter of a few millimeters up to ten centimeters and live in the high seas around the world.
features
Trachymedusae, in contrast to the Narcomedusae, have an unlapped umbrella with many radial canals. The radial canals connect the gastric space with an annular canal on the edge of the screen. Families and genera can be distinguished, among other things, by the number of radial channels .
At the edge of the screen there are tentacles in different numbers, which are mostly not hollow. The underside of the umbrella has strong muscles. The velum is large and well developed.
Systematics
The systematics given here follows the information in the Hydrozoa Directory .
The trachymedusae are divided into five families:
literature
- Gruner, H.-E., Hannemann, H.-J., Hartwich, G., Kilias, R .: Urania Tierreich, Invertebrates 1 (Protozoa to Echiurida) . Urania-Verlag 1993 ISBN 3-332-00501-4
- Jean Bouillon, Ferdinando Boero: Synopsis of the families and genera of the Hydromedusae of the world, with a list of the worldwide species , in: Thalassia Salentina, Vol. 24, 2000, pp. 65-66, PDF
