Purple sea urchin

Key facts

• Purple sea urchin lives in United States, Mexico, and Canada.
• Group: Sea animals.
• It weighs about 0.2 kg (0.441 lb).
• A typical adult is about 8 cm (3.15 in) long.
• It lives about 20 years.
• Diet: herbivore.
• Habitat: ocean.
• A sea urchin chews with five teeth inside its mouth, a set of parts known as Aristotle's lantern.