Purple Urchin (IMAGE) BMC (BioMed Central) Caption Pictured is the sea urchin, Strongylocentrotus purpuratus. Credit Ziegler et al., Frontiers in Zoology Usage Restrictions Please credit Ziegler et al., Frontiers in Zoology License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.