Layered Spicules (IMAGE) Brown University Caption The anchor spicules that hold the sponge species Euplectella aspergillum to the ocean floor have an intricately layered internal structure. Similar layered structures are known to increase the toughness of materials like bone and nacre. But this new research finds that the layering in the spicules does little to enhance toughness. The research could help to avoid "naive biomimicry," the researchers say. Credit Kesari Lab / Brown University Usage Restrictions None 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.