Figure 2. Call Types.

Different call types produced by wild caught spotted seatrout (Cynoscion nebulosus) held in captivity. Spotted seatrout produced three different call types. These calls were characterized as “drums,” “grunts,” or “staccatos” following similar nomenclature published in other studies (Mok & Gilmore, 1983; Sprague et al., 2000; Walters et al., 2009). (A) A continuous spectrogram illustrating a staccato (labeled 1), grunts (labeled 2), and a series of drums (labeled 3). Time domain of (B) a staccato, (C) a grunt, and (D) a drum call. Power spectral density (PSD) plots of (E) a staccato, (F) a grunt, and (G) a drum call. The sample rate was 50 kHz. In (A) the spectrogram was created using Adobe Audition with a spectral resolution of 2,048 and time duration of 10 s. Brighter colors correspond to higher sound pressure levels. Time domain and PSD figures correspond to the calls outlined in solid white lines in (A). PSDs of background noise in the tanks were calculated from recordings when fish were not present in the tanks. PSDs were determined using a FFT size of 1,024 samples, which corresponded to a frequency resolution of 48.8 Hz.