Clearfin lionfish.
Clearfin lionfish. The High Fin Sperm Whale/CC BY-SA 3.0

They can be awful pretty, but there are very few circumstances under which a lionfish is a welcome sight on a coral reef. They are voracious, aggressive, and territorial—and surrounded by a halo of long, twitchy, venomous spines. For divers and fishermen there is the risk of a sting, but it’s worse for full-time reef dwellers. One study conducted in the Bahamas by marine biologists from Oregon State University found that just one lionfish took out 80 percent of the juvenile fish in its territory. In the Caribbean, East Coast of the United States, and other places outside of their usual range on Indo-Pacific reefs, they are an invasive scourge with few natural predators.

Devising new strategies for limiting lionfish populations means learning as much as possible about their biology and behavior, including the sounds that they make. Scientists in North Carolina recently identified and recorded for the first time the “roar” of the lionfish, which is more of a guttural heartbeat that grows into a drum-like thumping when they’re agitated.

Understanding this sound and why they make it could make it easier to count lionfish in murky water—and make it more efficient to get rid of them. The only good way to get lionfish off a reef it to pluck them off by hand or net. It’s also known that they sometimes congregate in large numbers, so knowing the sounds they make could help scientists spot these gatherings, or even make it possible to attract them in large numbers, hopefully leading to a whole lot of ceviche and happier reef inhabitants. (So far, one of the most effective control campaigns was a push in Colombia to encourage people to eat lionfish—safe when prepared properly—on Fridays.)