Spawning sounds in meagre Argyrosomus regius recorded in the Gironde estuary, France

During their spawning period (June to mid-July) in the Gironde estuary, meagre Argyrosomus regius produce two distinct sounds: regular long grunts, the most common calls, and sometimes also short grunts. It is suggested that long grunts serve the formation of spawning aggregations and short grunts announce the beginning of courtship behaviour. The meagre's long grunts include long series of 30–112 closely spaced pulses placed into call units. Each pulse produces multiple and rapidly decaying swimbladder vibrations with a dominant frequency varying between 336 and 444 Hz.