Keeled Heart Urchin

Like regular sea urchins, keeled heart urchins have a flower-shaped or star-shaped pattern of holes on their bodies known as a petaloid. Tube feet extend out from these holes, helping the keeled heart urchin to breathe underwater!

However, unlike regular sea urchins, which have a more uniformly dome-shaped body, the body of the keeled heart urchin is more elongated, like an egg! This oval body shape helps it to burrow in sand and other sediments more effectively