| Gymnotiformes are South American weakly electric fish that produce weak electric organ discharges (EOD) for orientation, foraging and communication purposes. Because EOD properties vary widely across species, electric signals could serve a species recognition function. We quantified the electric signals of various species and used discriminant function analyses to verify whether these signals are species-specific based on different signal parameters. We found that the EOD waveform was a more specific cue than EOD frequency. Using Apteronotus leptorhynchus as a focal species, we complemented these measurements with playback experiments using stimuli of different species (varying in frequency, waveform, or both). In both a free-swimming experiment and a communication assay with restrained fish, we found that the subjects' behaviour was strongly influenced by the frequency of the stimuli but, opposite to what we predicted, the waveform of the stimuli had no measurable effect on either communication or locomotor behaviors. |
