Table 1.

Acoustic characteristics of L. griseus sounds; larval sounds were recorded in the field in the DISC, and in a tank in the laboratory; adult sounds were recorded in tanks by Fish & Mowbray [12], data are from the Macaulay Library [15]. In the field, larvae were placed inside an acoustically transparent cylindrical mesh chamber (38 cm diameter, 10 cm height) located 70 cm above the hydrophone. Therefore, the amplitude can be considered the approximate ‘source level’, because source level is typically measured at 1 m distance.

dominant frequency (Hz)duration (ms)amplitude (dB re: 1 µPa)
mean ± s.d.rangemean ± s.d.rangemean ± s.d.range
field knocks (n = 679)363.8 ± 56.9234.4–507.823.8 ± 4.211.1–42.2122.0 ± 2.65121.7–142.4
field growls (n = 172)291.6 ± 45.0102.5–395.5107.0 ± 71.022.6–140.0119.5 ± 6.6111.9–145.9
tank knocks (n = 162)287.2 ± 76.4239.6–582.718.9 ± 8.15.7–73.0
tank growls (n = 14)294.6 ± 12.4259.7–309.5220.2 ± 85.574.0–360.0
adult knocks (n = 12)247.0 ± 40.9129.2–273.431.5 ± 9.022.0–49.1