The South American electric fish (Order Gymnotiformes) possess, among their principal diagnostic features, a specialized electrogenic tissue, an electric organ, that generates discharges continually, since from several hours after hatching throughout their entire lives. Concomitantly, the gymnotiforms also have, embedded in their skin, a collection of specialized electroreceptor organs, which monitor the strength (amplitude) and the timing (phase) of the electrical field generated by their electric organ, in the space surrounding the fish. Any type of interference in the otherwise normal pattern of the electric field detected by the array of electroreceptors may become relevant information, as it can imply prey or predator, large or small, soft or hard, fast or slow, or a conspecific male or female. Because the electric organ discharges (EODs) are so vital for the fish, EOD waveforms and their possible variations are of utmost evolutionary relevance, as they become key elements for co-specifics’ recognition, sexual selection, reproductive isolation, agonistic interactions, hierarchical settlements, as well as to broadcast internal physiological states, gender and ontogenetic stages. Electrodes placed in the water near the fish can easily capture the EODs of individual fish and the electric signal can be digitized and subsequently visualized at an oscilloscope screen, or played as a sound through a loudspeaker. As consequence, we can “see” and “hear” the EODs of the different species, in real time. This possibility allows us to envision several opportunities to utilize these fish to capture the interest and the curiosity of visitors in scientific exhibitions and museums. Our laboratory in the Amazon has been interested in several aspects of the evolutionary biology of electric fish, from molecular systematics, to biogeography, to behavioral physiology. We also use the electric fish as a biosensor do infer about water quality, once these fish change their EODs’ pattern according to physic-chemical status of the water. In this Symposium I will describe our current research interests on electric fish in the Amazon and present a compiled review of our most recent discoveries in each respective field.