<i>Eubostrichus fertilis</i> (IMAGE) University of Vienna Caption This is a scanning electron microscopy image of a Eubostrichus fertilis worm (left) and its crescent-shaped bacterial partners arranged on its surface like the layers of an onion (right). Credit Copyright: Silvia Bulgheresi Usage Restrictions The image may only be used with appropriate caption or credit. 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.