Figure 4. Sound production of spotted seatrout throughout study period.

Sound production by wild caught spotted seatrout (Cynoscion nebulosus) held in captivity throughout the entire study period. The number of drums, grunts, and staccatos in each 2 min ‘wav file’ was manually counted by an observer and plotted versus date with corresponding water temperatures for (A) Tank 1, (B) Tank 2, and (C) Tank 3. The numbers above the horizontal arrows indicate the number of hours of light present in the respective photoperiod. Boxes indicate rapid fluctuations in water temperature. Generally, abrupt rises in temperature were followed by an increase in calling, while abrupt drops were followed by a decrease in the amount of calling.