Linnaeus, 1758
Common Sea Urchin
Description
Test usually globular, more rarely depressed or subconical; up to 16 cm in horizontal diameter. Colour of test an intense red, on which the white spines are very conspicuous. More rarely it is pale purplish or pale green.
Buccal plates
Buccal membrane with few, usually thin, plates, mostly imbedded in the skin, which appears rather naked. Three pore pairs in each ambulacral plate (E. esculentus test).
Spines
Test closely covered with short spines, among which the primaries are scarcely conspicuous. In smaller specimens, the secondary spines are not as large as the primary ones. Only every second or third ambulacral plate carries a primary spine.
Pedicellariae
Ophicephalous pedicellariae are found on the buccal plates. Globiferous pedicellariae are fairly large, usually with only one lateral tooth on each side, below the end tooth. Tridentate pedicellariae have long and slender blades.
Habitat
It is mostly found on hard-substrata with algae, but is found till depths of 1200 m.
Distribution
In the North Sea, the species is common in all areas with hard-substrata. Elsewhere it is distributed from Finmark and Iceland to the coast of Portugal. It is not known from the Mediterranean.
Remarks
This species can form hybrids with Echinus acutus and Psammechinus miliaris.