Although many animals use sounds to communicate, there is a notable difference between a person talking and a wolf howling… and a fish humming. Yet, we all use the same part of the brain to make sounds. Eric Libby reports.
Yes, fish makes sounds. Just like whales and other marine mammals, fish communicate with sound. It may be primitive and not too pleasant, but fish like croakers and toadfish hum, grunt, and growl for the same reasons as other vertebrates: to attract mates and to threaten territorial invaders.
Behavioral neuroscientist Andrew Bass from Cornell University found that vertebrates share a similar circuit of nerves in the brain responsible for communicating with sound. As he and his colleagues report in the journal Science, this collection of neurons acts as a pattern generator in vertebrates, including amphibians, reptiles, mammals, birds and fish.
He says pattern generators "are essential to [our] ability to time the sequence in which different muscles contract." Anytime someone speaks, that is a specific coordination of muscles. Fish have a simple mechanism for making sounds because they move only one pair of muscles. Humans, on the other hand, use multiple sets of muscles. Yet, Bass points out, "The same part of [our] nervous system that is essential to [our] ability to make sound is also present in their [fish] brain."
While human pattern generators are more complex, Bass's findings point to an evolutionary starting point for our vocal communication. Previous studies of fish communication have explored ways to track and monitor the size of fish populations. But, Bass's work has implications for human health. The simple system of neurons in fish communication may serve as a model for stroke-induced speech problems or motor neuron diseases.
Bass also hopes his work will make people more aware of fish vocal communication. There are an estimated 25 to 40 thousand species of fish, representing half of all vertebrates. And yet they are the least studied. We still have no idea how many species communicate or what they are saying. But Bass will continue listening.