This montage illustrates two brown ghost knifefish (Apteronotus leptorhynchus) communicating by means of electric signals. The spectrogram in the middle highlights a sequence of so called “chirps” that these neotropical fish use to synchronize spawning. Recordings of courtship, spawning, and aggression behaviors in natural habitats in Panamá revealed unexpected electrosensory stimuli that have been neglected so far in neurophysiological studies. For more information, see the article by Henninger and colleges (page 5456–5465).