Harmonic and temporal structure of electric organ discharges of the wave-type in Amazonian knifefishes (Gymnotiformes)

Communication and Waveform Analysis in Weakly Electric Fishes With Special Emphasis on Mormyrids

“…There is also the great waveform diversity of the EOD pulse itself, especially in mormyrids, and of continuous wave signals in apteronotid gymnotiforms (Kramer et al, 1981;Albert and Crampton, 2005;Hopkins, 1981;Kramer, 2019). Already early students of electric fish, such as Bennett (1971a), had observed and documented some of the great species diversity of EOD pulse waveforms in mormyrids and gymnotiforms, as well as of waveforms in certain wave gymnotiforms.…”

“…electric organ (Kirschbaum, 1983) of apteronotids soon degenerates and is replaced by a neurogenic organ that persists in adulthood (de Oliveira-Castro, 1955;Bennett, 1971a). The neurogenic organ affords the Apteronotidae waveforms of a higher frequency, of greater harmonic distortion, and great flexibility regarding the phase relationships among the constituent harmonics, resulting in a multitude of EOD waveforms (Kramer, 2019). The comparison of waveform diversity in mormyrids and apteronotids, and how it is achieved, shows that evolution can find similar solutions -species-specific EOD waveform diversity -by totally different means.…”

“…The JAR subserves a waveform discrimination function that would enable Eigenmannia sp. also to detect, for example, approaching apteronotid predators (that are reported to bite off Eigenmannia tails, or worse; Lundberg et al, 1996) by their characteristic EOD waveforms (Kramer, 1990(Kramer, , 2019.…”