From Don Knotts' portrayle of "Mr. Limpet" to the children's favorite "Nemo" and the tuna-pitching character in the "Sorry, Charlie" commercials, we all have seen fish that can talk. But that's just fiction, right?
Researchers say real fish can communicate with sound, too. And they say (the researchers, that is) that your speech skills and, in fact, all sound production in vertebrates can be traced back to this ability in fish. (You got your ears from fish, too.)
The new study was led by Andrew Bass (we did not make this up) of Cornell University.
The scientists mapped developing brain cells in newly hatched midshipman fish larvae and compared them to those of other species. They found that the chirp of a bird, the bark of a dog and all the other sounds that come out of animals' mouths are the products of the neural circuitry likely laid down hundreds of millions of years ago with the hums and grunts of fish.
"Fish have all the same parts of the brain that you do," Bass explained.
His team traced the development of the connection from the midshipman fish's vocal muscles to a cluster of neurons located in a compartment between the back of its brain and the front of its spinal cord. The same part of the brain in more complex vertebrates, such as humans, has a similar function, indicating that it was highly selected for during the course of evolution.
The finding is published in the July 18 issue of the journal Science.
The fish that Bass studied are interesting in their own right.
After building a nest for his potential partner, the male midshipman fish calls to nearby females by contracting his swim bladder, the air-filled sac fish use to maintain buoyancy. The sound is a hum, something like a long-winded foghorn. Female midshipman dig it, and they only approach a male's nest if he makes this call.
During midsipman mating season, houseboat owners in San Francisco Bay have complained that their homes vibrate from the humming, which sound like a high-speed motor running underwater.
By better understanding how these fish hear, the study offers new avenues to explore the causes of human deafness, the researchers say.