What did you say? Wolfgang Poelzer/WaterFrame/Getty

Hear them roar. Lionfish have been recorded making sounds for the first time.

Decoding these sounds could give us an insight into secret lives of this voracious invasive species – and help us keep tabs on its spread.

Many fish produce sounds to communicate with each other as low-pitched noises travel far underwater. “It’s a dominant mode of communication,” says Alex Bogdanoff at North Carolina State University.


Bogdanoff and his team decided to investigate the lionfish’s ability to produce sound after hearing reports from several divers that they make noises. This invasive species has been spreading through the Caribbean and east coast of the US. They often devour several organisms at a time, which is drastically reducing some native fish populations and altering ecosystems.

Underwater soundscape

The team recorded the underwater soundscape in an outdoor tank for five days, at first with a single lionfish and then with a group of five individuals. Occasionally, they stirred up the water with a net to see whether stress caused the fish to make different sounds (listen to the audio file, below).

The team found that the fish often produced a rhythmic sound similar to a heartbeat and to calls made by other fish. But they also produced another noise made up of a much quicker series of beats. “It sounds like the rapid beating of a drum,” says Bogdanoff.

Lionfish seemed to alter their calls when they were agitated, producing quicker and louder pulses. In follow-up experiments, the team found that they made sounds throughout the day, but were more vocal in the morning and evening.

Sounds are likely to vary between individuals as well. Bogdanoff and his team are now working on identifying these differences. They already have evidence that body size affects the noises that lionfish make. Males and females are likely to make different calls, so that they can find one another and reproduce.

Lionfish invasion

The researchers are interested in describing lionfish sounds to find out more about populations in different areas. Currently, divers are sent down for the task, which is costly and time-consuming. But once their range of sounds is pinned down, an array of hydrophones could be deployed around a reef to get an idea of the number, size and sex of lionfish living there.

The vocalisations could also help quantify lionfish invasions, says Aran Mooney at the Woods Hole Oceanographic Institution in Massachusetts. “This type of acoustic monitoring could be particularly helpful in locations that are difficult for divers to survey visually, such as deeper depths or murky waters,” he says.

Read more: Fish recorded singing dawn chorus on reefs just like birds

Although lionfish are likely to make sounds primarily to “talk” to other lionfish, Bogdanoff thinks they may also be communicating with other species. Populations in the western Atlantic don’t seem to have many predators and he is curious to find out if they are making noises to keep them away.

“Perhaps they are making aggressive calls to groupers, snappers, eels, for example, telling them to back off,” says Bogdanoff. “It’s something to look into.”

Journal reference: Journal of Fish Biology, DOI: 10.1111/jfb.13321

Read more: Fish recorded singing dawn chorus on reefs just like birds