The bacteria under the microscope (IMAGE) Max Planck Institute for Marine Microbiology Caption Microscopy image (fluorescence in situ hybridization (FISH) confocal microscopy) of tissues from a deep-sea mussel showing the intranuclear parasite Ca. Endonucleobacter in yellow, and the beneficial symbiotic bacteria in green and red. Cell nuclei are stained blue. The right panel is a zoom-in of the white square in the left panel. Credit Miguel Angel Gonzalez-Porras/Max Planck Institute for Marine Microbiology Usage Restrictions Only to be used in the context of this publication and citing the correct copyright. 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.