Description
This colonial ascidian was first detected in the Oosterschelde in 1977. In 1988 it was first observed in the Grevelingen. Its rounded shape feels smooth and looks like a spongy mass. The colony consists of small individuals (also called zoids) that are irregularly arranged side by side. They filter their food from the water. An inflow of water comes through body openings and the filtered water leaves through the cloacal openings. In many colonial ascidian individuals share a common outlet. In this species, each individual has its own cloacal opening.

Size
The colonies can reach a diameter of 100 mm and a height of 30 mm.

Colour
Semi-translucent bluish white to yellowish pink.

Habitat
On firm substrate.

Distribution
North Atlantic. Originally an arctic species, but also in the Netherlands since 2007.