- Kingdom: Animalia
- Phylum: Chordata
- Subphylum: Tunicata
- Class: Ascidiacea
- Order: Stolidobranchia
- Family: Pyuridae
- Scientific name: Boltenia echinata
- Norwegian: piggsekkedyr
This egg-shaped sea squirt is easily recognized by the branched tentacles giving it a cactus-like appearance. The diameter can reach 45 mm, 35 is more common. The color is usually yellow or light brown, sometimes with a tint of red or green.
Is most common on locations with a hard substrate from 10-15 and down to 350 meters depth.
It can be found in the North Atlantic Ocean, from the Arctic and as far south as the British Isles.