Knifefish (IMAGE) PLOS Caption A computer model of the knifefish illustrates the estimated SV for active sensing of prey (red) and stopping MV (blue). The backdrop shows a color map of the fish's simulated self-generated electric field. SV barely exceeds the stopping MV, revealing that the fish invests just enough energy into active sensing to detect prey in time to stop. Credit MacIver et al. Usage Restrictions All images are considered open access as long as the author is attributed. 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.