Glass Knifefish (IMAGE) Johns Hopkins University Caption Native to South America, the glass knifefish's ability to emits weak electrical signals makes it a superb subject for the study of how the brain uses sensory information to control locomotion. Credit Noah Cowan/JHU Usage Restrictions None 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.