Echinus esculentus is a globular sea urchin between 10 and 17 cm in
diameter. Spines are short, around 1,5 cm long, thick and regular. Their colour is variable: greenish
or pale purple. The thick
test is purple and red with five clearer bands on the ambulacral plates. When extending, tube-feet are
clearly visible among the spines. They are used to adhere to subtratum. The common sea urchin lives on
rocks where it feeds on seaweeds, especially laminaria, or bryozoans or other small invertebrates.
It is found from surface to 50 m deep, and sometimes at depths up to 1200m, in the Atlantic Ocean from Norway
to Portugal, in the English Channel and the North sea.
Phylum Echinodermata, class Echinoidea, order Echinoida, family Echinidae, Echinus esculentus Linnaeus, 1758.
Test: Rigid skeleton of sea urchins.
Ambulacral plates: Test plates pierced by numerous holes through which tube-feet can extend.
Tube foot: Tube-shaped element ending by a sucker-disc used to attach to subtratum.
Photograph: © Wilfried Bay-Nouailhat. Published with author's kind permission.
Echinus esculentus, Bay of Concarneau, South-Brittany, West of France. Depth 7 meters.
Text: Anne Bay-Nouailhat © 2005-2008.
Translation: Anne Bay-Nouailhat © 2007-2008.
