Invasive lionfish in the Caribbean Sea are scarfing down fish species that scientists haven't even discovered yet.
New research published May 25 in the journal PLOS ONE reveals video of a lionfish hunting a new species of yellow-and-orange goby off the coast of Curaçao. The gobies, dubbed Palatogobius incendius, or ember gobies, are a mere 0.8 inches (22 millimeters) long and hover just above the seafloor in deep reef areas. In the video, captured by the submersible Curasub in February 2015, a lionfish glides over a school of gobies, herding them against a rock wall and striking twice.
"Once we discovered invasive lionfish — sometimes in huge numbers — inhabiting barely explored deep reefs, our concern was that these voracious predators might be gobbling up biodiversity before scientists even know it exists," study co-author Carole Baldwin, the curator of fishes at the National Museum of Natural History in Washington, D.C., said in a statement. "This study suggests that they are doing just that." [Gallery: The Invasive Lionfish and its New Prey]
Lionfish (Pterois volitans and P. miles) originally hail from the Indo-Pacific, but arrived in the western Atlantic in the 1980s or 1990s. No one knows exactly how the fish invaded Atlantic waters, but home aquarists who dump unwanted lionfish into the ocean may have been the cause, according to the National Oceanic and Atmospheric Administration (NOAA).
Lionfish are adept hunters of gobies, which are small, schooling fish that tend to hover near rocks and the seabed, making them easy to herd and corner. The lionfish threat has helped put some goby species on the vulnerable and endangered species lists, Baldwin and her colleagues wrote in their new paper. But little is known about lionfish-hunting behavior in deep reefs, between about 165 feet and 985 feet (50 and 300 meters) down. In many areas, this level is known as the "twilight zone" because only dim light can penetrate that much water.