While sound may not be the first thing to come to mind when we think of fish, it is actually a key element of communication for the vast majority of fish species.

That is according to scientists at Cornell University, who have recently discovered that about two-thirds of all fish species in the world likely use sound to communicate.

As part of the study, researchers investigated the sounds of the ray-finned fish — a class of fish that makes up about 99 percent of all known fishes. Specifically, the researchers analyzed existing papers on fish sounds, recordings of those sounds, and references to such sounds in 19th-century literature (before the invention of the hydrophone).

Additionally, the scientists studied in detail the anatomy of various species of ray-finned fishes, in a bid to find out what characteristics they have in common with fish that are already known to vocalize. Among these characteristics are sound-specific muscle groups, an air bladder, and distinctive bones, reports New Atlas.

According to the study results, a total of 175 families of ray-finned fishes — about two-thirds of all fish — either use sound to communicate or were considered likely to do so. Similar to other species of animals, fish use vocalization to send across messages focused on attracting mates, protecting food resources and territories, or announcing their location.

“This introduces sound communication to so many more groups than we ever thought,” said Rice. “Fish do everything. They breathe air, they fly, they eat anything and everything – at this point, nothing would surprise me about fishes and the sounds that they can make.”

Source study: Ichthyology & Herpetology – Evolutionary Patterns in Sound Production across Fishes