This common compund ascidian is usually found on jetty pylons, where it forms pale pink lobed colonies. Each lobe has a terminal cloacal aperture, which can be small and circular, or a long and irregular channel. These channels continue under the test, where they are usually visible as semi-transparent zooid-free "veins" in the colony. Branchial apertures are irregularly arranged, and have a thick white rim. There are a number of species that are almost identical to this, and positive ID is extremely difficult. However, in some cases, it can be distinguished from the soft and jelly-like Aplidium multiplicatum by its comparatively firmer, gelatinous test, which is less affected by wave action than A. multiplicatum.
