SAN JUAN, Puerto Rico — A maroon-striped marauder with venomous spines is rapidly multiplying in the Caribbean's warm waters, swallowing native species, stinging divers and generally wreaking havoc on an ecologically delicate region.
The red lionfish, a native of the Indian and Pacific oceans, is showing up everywhere — from the coasts of Cuba and Hispaniola to Little Cayman's pristine Bloody Bay Wall, one of the region's prime destinations for divers.
Wherever it appears, the adaptable predator corners fish and crustaceans up to half its size with its billowy fins and sucks them down in one violent gulp.
Research teams observed one lionfish eating 20 small fish in less than 30 minutes.
"This may very well become the most devastating marine invasion in history," said Mark Hixon, an Oregon State University marine ecology expert. "There is probably no way to stop the invasion completely. … We've not seen such a large predatory invasion in the ocean before."
The lionfish has been concentrated in the Bahamas, where marine biologists are seeing it in every habitat, including mangrove thickets that are vital for baby fish.
"I think at the best they will have a huge impact on reef fish, and at the worst will result in the disappearance of most reef fish," said Bruce Purdy, a veteran dive operator who has helped the marine conservation group REEF with expeditions tracking the invasion.
Purdy said he has been stung several times while rounding up lionfish — once badly. "It was so painful, it made me want to cut my own hand off," he said.
Researchers believe lionfish were introduced into the Atlantic in 1992, when Hurricane Andrew shattered a private aquarium and six of them spilled into Miami's Biscayne Bay, according to the National Oceanic and Atmospheric Administration.
Researchers are scrambling to figure out what will eat the menacing beauties, experimenting with predators such as sharks, moray eels — and even humans.
Adventurous eaters describe the taste of lionfish as resembling halibut. But so far, they are a tough sell. Hungry sharks typically veer abruptly when researchers try to hand-feed them a lionfish.
One predator that will eat lionfish is grouper, which are rare in the lionfish's natural Southeast-Asian habitat. Scientists are pinning long-range hopes on the establishment of new ocean reserves to protect grouper and other lionfish predators from overfishing.