The Disease Affects Gill Tissue (IMAGE) University of Veterinary Medicine -- Vienna Caption Necrotic gill tissue of a diseased koi. Credit Courtesy of Eva Lewisch/Vetmeduni Vienna Usage Restrictions The photo may only be used in the context of this press release. 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.