Purple sea urchin can refer to one of several species of sea urchin:

• Arbacia punctulata, a species of sea urchin from the family Arbaciidae commonly known as the Atlantic purple sea urchin
• Paracentrotus lividus, a species of sea urchin in the family Parechinidae commonly known as the purple sea urchin
• Strongylocentrotus purpuratus, a species of sea urchin in the family Strongylocentrotidae commonly known as the purple sea urchin

This disambiguation page lists articles associated with the title Purple sea urchin.
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