Thick-horned water lily
| Thick-horned sea anemone | ||||||||||||
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Thick-horned sea anemone ( Urticina felina ) |
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| Scientific name | ||||||||||||
| Urticina felina | ||||||||||||
| Linnaeus , 1767 |
The thick-horned water lily ( Urticina felina ) is a sea anemone (Actiniaria) that occurs in the northern Atlantic , the Arctic Ocean , the English Channel , the North Sea and the western Baltic Sea . There it lives on rocky ground, on moles and bridge piers from the intertidal zone to a depth of 600 m.
features
This water lily can easily be recognized by its compact, cylindrical and very strong developed trunk, which is attached to the ground with a strong, but not protruding foot disk. Around the large mouth area there are 80 to 160 strong tentacles, which do not taper off like in the horse action line , but end bluntly. Numerous nipples on the outside of the fuselage hold a lot of algae , sand and schill particles and thus cover the actual body wall. The coloring of the animals is very variable. In addition to monochrome specimens (e.g. bright red or green, then easily confused with the horse line), there are numerous drawing variations. The outside of the trunk can be banded or spotted, the base of the tentacles is often flanked by two longitudinal strips that unite at the base of the tentacles and continue to the mouth / anal opening. The tentacles themselves are often banded in bright colors. The colors vary between dirty white, yellow, red, brown, green, blue and almost black. When stretched out, the animals reach a height of 15 cm. The span of the tentacle crown is up to 20 cm.
Way of life
The water lily can be found particularly often in smaller groups, standing close together in larger, light-flooded tidal pools. The water lilies unfold their full activity at nightfall. Then they catch small fish , shrimps and other small crustaceans from the water with their strong arms and, after eating them vigorously, stuff them directly into the body opening. A person who holds his finger in the tentacle crown feels the sticky adhesive effect of the tentacles very clearly, but the touch is harmless and he is not dangerously stinged. In the resting state, the tentacles are withdrawn. The same behavior can also be observed when the animals that live in the intertidal zone fall dry and are threatened with excessive water loss. To the viewer, they only appear as an unsightly, small, soft lump that gives no idea of the beauty that the anemone unfolds under water. Due to the camouflage with attached particles and algae, the water lilies are very difficult to make out in the open. The water lilies survive longer periods of hunger due to their low metabolic activity without damage. In an emergency, they can feed on their own body reserves. Their frugality makes them popular exhibits in public marine aquariums. Water lilies are sexually separated. For reproduction, the males release their sperm into the open water. From there, they enter the interior of the female and fertilize the eggs. Depending on the quality of the environmental conditions (e.g. salt content of the water, temperature level and fluctuations), the fertilized eggs are either released into the open water or retained in the body cavity until fully developed young animals have finally formed. These are expelled through the body orifice and drift with the flow of water.
literature
- Josef H. Reichholf and Gunther Steinbach (editors): Mollusks and other invertebrates, invertebrates, molluscs, single-celled organisms, microorganisms. The large Bertelsmann Lexikothek - Naturenzyklopädie der Welt, Volume 6, Mosaik Verlag, 1993, ISBN 3-576-10106-3
- Jürgen Lange, Rainer Kaiser: Lower animals of tropical and cold seas . Ulmer, Stuttgart 1991, ISBN 3-8001-7222-4
