Sclerites (IMAGE) University at Buffalo Caption Calcium carbonate structures called clubs and spindles isolated from Plexaura homomalla, as viewed under a microscope. This visual is a composite that combines focus-stacked microscope images of individual sclerites. Areas of light and shadow have been enhanced to better visualize the structures. A new study finds variation in the shape and size of sclerites produced by P. kükenthali and P. homomalla. Credit Credit: Jessie Pelosi, adapted from an image published in Coral Reefs. https://link.springer.com/article/10.1007/s00338-021-02175-x#rightslink Usage Restrictions Credit must be given to the creator. License CC BY 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.