It is well known that fish communicate by gesture and motion, as in the highly regimented synchronized swimming of schools of fish.
Some kinds of fish also release chemicals that can be sensed by smell or taste. In 2011, a scientist in New Zealand suggested that what might be called fish vocalization has a role, at least in some ocean fish.
In the widely publicized work, done for his doctoral thesis at the University of Auckland, Shahriman Ghazali recorded reef fish in the wild and in captivity, and found two dominant vocalizations, the croak and the purr, in choruses that lasted up to three hours, as well as a previously undescribed popping sound.
The sounds of one species recorded in captivity — the bigeye, or Pempheris adspersa — carried 100 feet or more, and the researcher suggested it could be used to keep a group of fish together during nocturnal foraging. Another species, the bluefin gurnard, or Chelidonichthys kumu, was also very noisy, he found.
“Vocalization” is a bit of a misnomer, as the sounds these fish make are produced by contracting and vibrating the swim bladder, not by using the mouth. firstname.lastname@example.org