A communication signal in an African freshwater electric fish, its pulse-like Electric Organ Discharge (EOD), was investigated in order to determine whether inter- or intraindividual variability of the EOD waveform provides a putative cue for communication, in addition to the electric cues already identified. In contrast to an individual's highly stereotyped EODs showing extremely low variation (fig. 1), variability between individuals was considerable (fig. 2). The dependence of an individual's EOD duration on temperature was weak with a Q10 of close to 1.5. In none of four quantitative EOD waveform measures can a sexual dimorphism be discerned (table).Gnathonemus petersii very likely relies on mechanisms other than discrimination of intraspecific EOD waveforms for mate recognition.