Red Sea Urchin

Red Sea Urchin (Strongylocentrotus franciscanus ) as seen in our Coastal Waters exhibit.

Red Sea Urchins can range in color from pink to deep red to purple. These large urchins have long, straight, smooth spines. They eat a variety of brown and red algae but prefer giant kelp, Macrocytis. They have movable jaw parts called an Aristotle’s lantern that cut seaweed into portions small enough for them to ingest. Like Sea Stars, urchins move by flexing their spines together with their tube feet. All urchins are related to Sea Stars, California Stichopus (Sea Cucumbers) and Sand Dollars. Large adults may live as long as 20 years.

Range & Habitat 

Red Sea Urchins can be found Alaska to Baja California. They’re uncommon in the very low intertidal zone but become more abundant subtidally to a depth of 295 feet (90m). Juvenile Red sea urchins are often found beneath the outspread spines of adults.

Conservation Status