The lionfish (Pterosis volitans), a beautiful but deadly Indo-Pacific fish that is popular in the aquarium hobby, has become an invasive species up and down the Atlantic Seaboard and into the Caribbean thanks in part to unscrupulous aquarium keepers who released their fish into the Atlantic.
The fish has no natural predators in the Atlantic or the Caribbean, because they are not native, but groupers (Serranidae sp.) have been known to prey on them. A 2011 study noted that Caribbean reefs with high grouper counts had low lionfish populations.
At the time, it wasn’t certain if grouper had lionfish on their menu as there were also studies that some grouper avoided lionfish, probably due to their venomous fins that sometimes are larger than the fish’s body.
However, in February 2015 Lionfish University, an advocacy group that works to educate the public about the invasive fish and to work to control their numbers on reefs on the East Coast and in the Caribbean, released a video showing a grouper coaxing a lionfish off the reef into open water, where the grouper proceeds to devour the fish, fins and all.
The video is telling in that it shows the grouper outmaneuver the lionfish while avoiding the fish’s venomous fins until it gets it up into the water column, where it then proceeds devour the fish. This footage is thought to be the very first grouper/lionfish documentation caught on video showing a grouper working its way to eat a live lionfish. There apparently have been “teaching” moments in which divers present lionfish to them and they eat them, but this video shows a grouper working on its own to fish the lionfish out of the safety of the reef and into open water before it goes for the kill.