Coral Skeletons 3 (IMAGE) Johns Hopkins University Caption Johns Hopkins University post-doc Justin Ries and collaborators demonstrated that corals can build their skeletons out of different minerals depending on the chemical composition of the seawater around them. Credit Will Kirk/JHU 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.