Niger Triggers are my favorites, next to the Mantis Shrimp. The Nigers are very beautiful and seem to be so full of personality. People tell me I am crazy, but I have never had a problem with a Niger or a Mantis. Ten years ago, when I had a small 10 gallon live rock-invert-fish tank, I had a single Niger in with a Coral Banded Shrimp, a couple Feather Dusters, and Florida Live Rock. The Niger never bothered anything. This back when you could get Florida Rock that was harvested from the wild, with loads of Christmas Tree Worms and other fun surprises.
Breaking down that tank and selling it when we moved was a pretty sad day.
As long as you do not have any inverts that would become a tasty snack for the Lionfish, I would say try it. If your Niger is one of the smaller ones like mine was, I am of the belief that they can learn to love thy neighbor. Just like people though, every one of them has a different personality. Start small and slow, but be prepared to remove something if you notice an issue. If your supplier has a return or buy-back policy, that is even better.
Corals that could survive with aggressive fish 
Re: Corals that could survive with aggressive fish 
