- Kingdom: Animalia
- Phylum: Echinodermata
- Subphylum: Echinozoa
- Class: Echinoidea
- Order: Camarodonta
- Family: Echinidae
- Scientific name: Echinus esculentus
- Norwegian: rød kråkebolle
Characteristics:
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.
Habitat:
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.
Distribution:
The common sea urchin is known from the North-East Atlantic Ocean, from Norway and Sweden to the Azores.