The dorsal surface of the body is black, with pink, grey, greenish or bluish tubercles forming longitudinal rows.

The front-most tubercles are set obliquely, sloping towards the centre of the back.

It has neither a radula, jaws, or a stomach, and feeds by turning part of its gut inside out, using its digestive enzymes to break down the sponge's tissues, and sucking in the liquified product.

A pair of individuals move close to each other while facing in opposite directions, and transfer sperm to each other.

There is no larval stage and the embryos undergo direct development into juveniles.