This is an interesting twist in the cycle of life under the see. I have been a salt water aquarium owner for about 2 years now and I’ve always wanted to own a Lionfish but it is a bit expensive. I know that these fishes have a very limited to no natural predators and that is why they thrive. I saw this article in NatGeo and read that in the Honduras local dive masters who are familiar with the sharks decided to try to turn them on to eating invasive lionfish.
As for a Natural Predator if these fish weren’t spiky we as humans probably could be one of them. Who knows maybe there could be some of us that eats them and it’s just not published. Maybe in Japan they can come up with a sushi for this fish. I will search for this and update you when I find a topic regarding lionfish as food for us.