Most representatives of this species are omnivorous. Sea urchins eat a variety of algae, mollusks, sponges, carrion, as well as starfish and sea urchins of smaller size. Some representatives of this species are known for the power to catch and eat a mantis cancer. Sea urchins, which live in sandy or soft ground, eat silt and sand, swallowing with it microscopic organisms.
Food sea urchins absorb the mouth, which is in the lower part of the trunk. In the mouth of the hedgehog there are five jaws, each of which is placed along a row of powerful teeth growing throughout life. With their mouthpiece, sea urchins easily scrape off algae and other small organisms from stones.
In turn, sea urchins serve as food for many species of fish, birds, sea stars, lobsters, fur seals, but the largest hunter on sea urchins is the sea otter. Many otters from using a large number of hedgehogs, bones and insides are sometimes stained with a purple pigment.