Croaker

croaker a general name applied to a large number of species of fish in the family Sciaenidae. This family includes 200 or more species, some of whose members will be found under drum (another general name), kingfish, and meagre. The name croaker, although imprecise, is used with reason, since it is normally applied only to those sciaenid fish which can make a croaking (or drumming) noise. Scott (1959) explains that the croaking

comes from their ability to produce a loud, croaking sound, similar to that of a frog. The large swim-bladder is used as a sounding box. The noise is not only heard when the fish has been pulled out of the water but is clearly audible by underwater listening devices and to the Malay ‘Jeru selam’ who lowers himself under the water and listens for the noises made by shoals of fish from which he can deduce the size of the shoal, species of fish and their approximate position, after which he directs his fishermen to set the net to capture the fish. Even persons drifting in a small boat while fishing have been mystified by the loud ‘frogs’ chorus’ suddenly starting up all round them, the source of which remained unseen until they started to catch the still-croaking vocalists.