MBL, WOODS HOLE, MAA male midshipman, a close relative of the toadfish, doesn't need good looks to attract a mate just a nice voice. After building a nest for his potential partner, he calls to nearby females by contracting his swim bladder, the air-filled sac fish use to maintain buoyancy. The sound he makes is not a song or a whistle, but a hum; more reminiscent of a long-winded foghorn than a ballad. Female midshipman find it very alluring, and they only approach a male's nest if he makes this call.
In a paper published this week in Science, three Marine Biological Laboratory (MBL) visiting investigators show that the sophisticated neural circuitry that midshipman use to vocalize develops in a similar region of the central nervous system as the circuitry that allows a human to laugh or a frog to croak, evidence that the ability to make and respond to sound is an ancient part of the vertebrate success story.
The research is presented by Andrew Bass of Cornell University, Edwin Gilland of Howard University College of Medicine, and Robert Baker of New York University Medical Center.
"Fish have all the same parts of the brain that you do," says Bass, the paper's lead author. The way our brains work is also similar. Just as we have neurons that coordinate when our larynx and tongue change shape to produce words, toadfish and midshipman orchestrate the movement of muscles attached to their swim bladder to produce grunts and hums.
Using larval toadfish and midshipman, the group traced the development of the connection from the animal'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.
Scientists have known for decades that these fish make sounds, but they are not
|Contact: Diana Kenney|
Marine Biological Laboratory