Fig. 4 in On Apteronotus magdalenensis (Miles, 1945) (Gymnotiformes: Apteronotidae): a poorly known species endemic to the río Magdalena basin, Colombia

Fig. 4. Electric Organ Discharge (EOD) waveform (left) and Power Spectral Density (PSD) (right) of Apteronotus magdalenensis. (a): IAvH-P 9836, WC 2005-09-27-01, male, 360 mm TL, Nikolsky gonad stage 4 (fully mature). (b): IAvH-P 7026, WC 2005-09- 27-03, female, 326 mm TL, Nikolsky gonad stage 4 (fully mature). Waveforms are plotted head-positivity upwards, time on abscissa (scale bar = 1 ms), voltage on ordinate, horizontal dashed line = 0 volts. PSD were computed by 65536=point fast Fourier transform from 3s digital recordings. Amplitude on ordinate is scaled so that the peak power frequency is 0dB.