Translations:Fish/88/en

Some fish produce sounds by rubbing or grinding their bones together. These sounds are stridulatory. In Haemulon flavolineatum, the French grunt fish, as it produces a grunting noise by grinding its teeth together, especially when in distress. The grunts are at a frequency of around 700 Hz, and last approximately 47 milliseconds. The longsnout seahorse, Hippocampus reidi produces two categories of sounds, 'clicks' and 'growls', by rubbing their coronet bone across the grooved section of their neurocranium. Clicks are produced during courtship and feeding, and the frequencies of clicks were within the range of 50 Hz-800 Hz. The frequencies are at the higher end of the range during spawning, when the female and male fishes were less than fifteen centimeters apart. Growls are produced when the H. reidi are stressed. The 'growl' sounds consist of a series of sound pulses and are emitted simultaneously with body vibrations.