Fig. 3. Relationship between dominant frequency and pulse duration for (A) fish ranging from 25 to 36 cm in total length (recorded at 18 °C, N=11) and (B) fish recorded at 12, 18 and 23 °C (28-31 cm in total length, N=8). (C) A plot of dominant frequency divided by a frequency calculated from the period of the second cycle of acoustic energy (shaded bar in inset). Frequency was calculated as [1000/(the duration of the second cycle of acoustic energy)]. Note that the dominant frequency is closely matched (expressed as values near to 1) by the inverse of the duration of the second cycle of acoustic energy. Figures modified from Connaughton et al. (2000).