Red lionfish hunt like a "terminator", researchers say.
Invasive predators hunt in areas where prey is abundant. These hunters usually move to a different location when the population of prey declines. The red lionfish, however, chooses to stay at a specific location until it eats all the available prey. The lionfish's behavior can lead to the extinction of an entire local population of a species.
"Lionfish seem to be the ultimate invader," said Kurt Ingeman, a researcher from Oregon State University, according to a news release. "Almost every new thing we learn about them is some characteristic that makes them a more formidable predator. And it's now clear they will hunt successfully even when only a few fish are present. This behavior is unusual and alarming."
The red lionfish (Pterois volitans) is also called a "ghost fish" because it is almost impossible to see it in a coral reef. The fish species is venomous and can grow to about 15 inches in size. Its body is covered with reddish-brown bands separated by white lines, which helps it hide in the coral reefs.
For the study, the researchers analyzed hunting behavior of red lionfish. The fish species were placed with fairy basslet - a popular aquarium fish and a common prey of lionfish in replicated natural reefs in Bahamas.
The researchers then compared mortality of fairy basslet in the presence of red lionfish to the rate of fairy deaths around other natural predators. The team found that lionfish nearly wiped out the entire local population of fairy basslet.
"Reef fish usually hide in rocks and crevices for protection, and with high populations, there is a scramble for shelter," Ingeman said in a news release. "Native predators take advantage of this situation by mostly eating when and where prey are abundant. As prey population levels decline, it takes a lot more energy to catch fish, so the predators often move on to other areas."
The National Science Foundation and the Cape Eleuthera Institute of the Bahamas supported the study and it was presented at the annual meeting of the Ecological Society of America.