Eigenmannia and other weakly electric fish use active electrolocation – they can locate objects by generating an electric field and detecting distortions in the field caused by interference from those objects. Electric fish use their electric organ to create electric fields, and they detect small distortions of these fields using special electroreceptive organs in the skin. All fish with the JAR are wave-discharging fish that emit steady quasi-sinusoidal discharges. For the genus Eigenmannia, frequencies range from 240 to 600 Hz. The EOD frequency is very steady, typically with less than 0.3% variation over a 10-minute time span.
