Real sea urchins
| Real sea urchins | ||||||||||||
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Purple sea urchin ( Strongylocentrotus purpuratus ) |
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| Scientific name | ||||||||||||
| Echinoida | ||||||||||||
| Claus , 1876 | ||||||||||||
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The order of the real sea urchins (Echinoida) includes the most common and best-known sea urchins of the European coasts, z. B. the edible sea urchin ( Echinus esculentus ) and the stone sea urchin ( Paracentrotus lividus ) from the family of Echinidae and the species-rich genus Strongylocentrotus from the family of Strongylocentrotidae .
features
The real sea urchins belong morphologically to the "regular" sea urchins (formerly known as regularia). A five-point, radially symmetrical limestone skeleton and an apple-shaped shape are characteristic of these. The mouth lies on the underside in the middle of a membranous mouth field. The anal opening is in the center of the top. In the middle of the mouth are the tips of the five teeth, which are anchored in a complex jaw structure, which Pliny the Elder called " Aristotle's Lantern " because of its shape . In the Echinoida, as in the order of the Temnopleuroida, the cutouts in the jaw structure that widens upwards are bridged by braces. However, the Echinoida have no special depressions on the shell surface and the gill slits are indistinct and not cut as deeply as in the Temnopleuroida.
literature
- Bernhard Grzimek (ed.): Grzimeks animal life. Encyclopedia of the Animal Kingdom in 13 volumes. Volume 3: molluscs and echinoderms. Unchanged reprint of the dtv edition from 1979/80. Bechtermünz-Weltbildverlag, Augsburg, 2000 ISBN 3-8289-1603-1
