Croaker

Croaker is the smallest member of the Sciaenidae family of drums. The species gets its name from the croaking sound it makes from the voluntary contraction of muscles attached to the air bladder, which acts like a resonance chamber. It’s unclear whether the croaking is a form of communication within a school of fish, a means of depth sounding or a mating expression, but croakers tend to make the sound most often during breeding season.