Red Encrusting Sponge (Clathria pennata)

Description: Red encrusting sponge is a bright red to red-orange color. The pores are very small and not very noticeable, especially compared to the purple encrusting sponge. Since the sponge conforms to the shape of the rock it’s living on, they often look like part of the rock itself.

Habitat: The red encrusting sponge is found in the high intertidal zone to depths of 90 m and from Alaska to Baja California, Mexico.

Diet: Like other sponges, the red encrusting sponge filter feeds for detritus, plankton, and other particles in the water column.

Tide Pool Tidbits:

• Red sponge eating nudibranchs are often found on top of or next to patches of red sponge. They are the exact color of the sponge, so to see them you need to look very closely for a tiny dorid shaped lump.

• There are several species of sponge that look very similar to this species and a microscope is needed to differentiate between them. The species listed here (Clathria pennata) is the most common species.

Reference: The New Beachcomber’s Guide to the Pacific Northwest by J Duane Sept