It has a deep red hue both on the outside and inside. The surface is covered by a translucent whitish membrane with radial canals that meet at the openings (oscula). It forms either low or tall masses in various shapes, such as bushy, rounded, or fan-shaped structures. Occasionally, it develops short, tube-like protrusions that terminate in oscules. There are also short, irregular branched extensions, ridges, or lumps supported by subdermal skeletal elements. The oscules are elevated. Transparent exhalant canal systems may converge around the oscules, revealing a red to reddish-orange interior color, but this collapses and becomes inconspicuous when the animal is removed from water.