Paramormyrops hopkinsi (Taverne & Thys van den Audenaerde, 1985)

A large, head-positive peak, P1, which reaches about 75% of the peak to peak height, is followed by a small head-negative peak, P2, which is only 25% of the peak-peak height. Following P2, the voltage trace returns toward baseline, but then with a delay of three to six msec shows another characteristic head-negative peak. Female EODs tend to be shorter than males but the overall waveform is the same. The average duration of EOD pulses is 4.32 msec for all fish tested. The power spectrum of the EOD peaks at 0 Hz (i.e. D.C.) as expected for pulses that are predominantly monophasic. The electric organ has electrocytes with non-penetrating stalks innervated on the posterior surface. A second variant EOD has been observed in populations of P. hopkinsi from the Ivindo River.