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Fish Use Dramatic Pauses Too, Wash U Professor Finds

Tsunehiko Kohashi
Electric fish communicate with one another via a series of discrete pops underwater — and pause when they want their message to have a strong impact on the receiver.

Since the 1960s, researchers have known that some fish species use electric impulses to communicate. Washington University biology professor Bruce Carlson, who first learned about electric fish in an undergraduate course, was immediately intrigued.

Robert Lewis
Elephant fish are freshwater fishes found in Africa. The elephant fish Bruce Carlson works with, the Brienomyrus brachyistius, is commonly referred to as the baby black whale.

“There’s a whole sensory world under the water we are totally oblivious to,” he told St. Louis on the Air.

Carlson has made his name studying electric fish, with more than two decades of research to his name. His latest study on Brienomyrus brachyistius — an electric fish species known as the baby black whale — demonstrates how the fish use dramatic pauses in their communication. The waveforms, shapes and timing of the electric pulses provide their fellow fish with information about species, sex, reproductive status, age and perhaps even individual identities.

“They're also communicating contextual information about their behavioral state,” Carlson said. “So things like, ‘I'm looking for a mate,’ or ‘I'm receptive,’ or ‘This is my territory; bug off,’ or ‘I'm going to attack you,’ or ‘I submit; you win’ — these various kinds of contextual communication that many nonhuman species communicate with each other.”

Carlson’s research provides humans with a reminder that we are far from unique in being able to share information with one another. Said Carlson, “Non-human animal communication is more nuanced and sophisticated than we appreciate.”

Carlson joined St. Louis on the Air to discuss his latest work, as well as what his lab’s research tells us about the evolution of communication in the animal kingdom.

St. Louis on the Air” brings you the stories of St. Louis and the people who live, work and create in our region. The show is hosted by Sarah Fenske and produced by Alex Heuer, Emily Woodbury, Evie Hemphill and Lara Hamdan. Paola Rodriguez is our production assistant. The audio engineer is Aaron Doerr.

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