Description
The colony consists of small individuals that are tightly arranged. There are several similar species that can only be identified by studying the larvae under a microscope. Thees are the compound ascidians Botrylloides leachi, Botrylloides simodensis and Botrylloides violaceus. It is assumed that the single-colored dark red form, is the Botrylloides violaceus

Size
A colony can cover area's of 20 to 30 cm.

Colour
The colour can vary from bright orange to dark red, but never bicolored. The bicolored white, pink and or purple colonies are Botrylloides diegensis.

Habitat
On hard substrate in shallow subtidal waters.

Distribution
This species originates from the north western Pacific, but is now thought to have a world wide distribition.