This encrusting colonial ascidian is common on jetty pylons and rock walls, consisting of branching vertical lobes that rejoin each other in various places, creating a network of irregularly-shaped gaps. Its surface test is packed with spicules, giving the colony an opaque, yellowish-cream colouration, interspersed with black zooids and large cloacal apertures with transparent rims. It is similar in appearance to Trididemnum nobile, although that species reportedly has much less dense spicules, and appears more black and translucent.
