- Kingdom: Animalia
- Phylum: Echinodermata
- Subphylum: Echinozoa
- Class: Echinoidea
- Order: Camarodonta
- Family: Echinidae
- Scientific name: Echinus esculentus
- Norwegian: rød kråkebolle
It is the largest sea urchin in Norway, the shell may reach a diameter of 16 cm. The spines are relatively short. It sometimes hybridize with the Gracilechinus acutus or Psammechinus miliaris, producing offspring that are hard to identify.
It lives on all depths down to at least 1200 meters. It seems to thrives in a large variety of habitats, but is perhaps most frequent on hard substrate, among algae.
The common sea urchin is known from the North-East Atlantic Ocean, from Norway and Sweden to the Azores.