Collecting samples of Pocillopora corals (IMAGE) Rice University Caption Marine biologists sample reefs of Pocillopora corals. Researchers at Rice University and Oregon State University studied corals and found fragments of non-retroviruses in the genomes of their symbionts, perhaps the result of infections millions of years ago. (Credit: Andrew Thurber/Oregon State University) Credit Credit: Andrew Thurber/Oregon State University Usage Restrictions Must credit: Andrew Thurber/Oregon State University License Original 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.