- Kingdom: Animalia
- Phylum: Echinodermata
- Subphylum: Echinozoa
- Class: Echinoidea
- Order: Camarodonta
- Family: Echinidae
- Scientific name: Gracilechinus acutus
- Norwegian: langpigget kråkebolle
The long spines are characteristic for this sea urchin. However, hybrids exist, that can be difficult to identify. The shell is usually white, perhaps with shades of red or black. The color of the spines varies, both white, black and red is common. The diameter of the shell can reach 16 cm. This sea urchin is formerly known as Echinus acutus.
It is usually found on gravel or rocky substrate, deeper than 20 meters.
G. acutus is distributed from the Barents Sea to the Azores and the Mediterranean.