This species has been given many scientific names in the past. Because it is so variable in size, shape and colour, scientists classified it as many different species only to find they were all the same.
The Dark Ascidian may sometimes be difficult to distinguish from encrusting sponges in Sydney as they are both found in similar habitats.
The Dark Ascidian is found in coastal waters to a depth of 25 m. The Dark Ascidian is a common species, occurring on seaweeds on the lower shore and in shallow water.
Other behaviours and adaptations
The Dark Ascidian is an example of a colonial ascidian, meaning that many individual animals live together embedded in a jelly-like substance. Each individual in the colony has its own intake siphon for feeding, but several individuals may combine to share one exit siphon.