- Kingdom: Animalia
- Phylum: Chordata
- Subphylum: Tunicata
- Class: Ascidiacea
- Order: Stolidobranchia
- Family: Styelidae
- Scientific name: Botryllus schlosseri
- Norwegian: kolonisekkedyr
Characteristics:
These colonial sea squirts form 2-4 mm thick sheets. The zooids (animals) are positioned in star shaped formations. In the center of each star there is a common cloak siphon (opening). Each formation includes between 6 and 12 individuals. The color may vary, but white or pale yellow stars on a brown background is common.
Habitat:
These beautiful formations encrust hard surfaces or algae, from the intertidal zone and down to 40 meters depth.
Distribution:
It is widespread in the Atlantic Ocean, on both hemispheres.