This purple sea urchin feeding (Strongylocentrotus purpuratus) on a piece of kelp seems very interested as its many tube feet grasp towards the morsel. Purple sea urchins literally dig themselves a protective recess into the surrounding rock and then rely on algae to drift and settle nearby as a food source.
These urchins live close to the surface, and use their strong spines to dig deep depressions. These hollowed out rock areas provide protection from crashing waves and violent storms that hammer the open ocean coastline. The purple sea urchin has a range that includes Japan, as well as northern Alaska to northern Mexico, and they can grow to 6 inches (15 cm) across. These urchins live in the intertidal zone down to around 215 feet (65 m) of depth, and may live as long as 70 years of age.