Intertidal Invertebrates of the Monterey Bay Area, California

Compiled & photographed by Gary McDonald, Long Marine Laboratory, University of California, Santa Cruz

Description: May be red, orange-brown, yellow-tan, salmon-red, terra cotta, or mustard, forming an encrustation up to 8mm thick on rocks; oscules not elevated, often with radiating stellate pattern of grooves around oscules. As with many sponges, the spicules must be examined identify this species.
Notes: This is one of several red or orange sponges on which the nudibranch Rostanga pulchra feeds.