For the record, I don't think it right for DMs to feed the lionfish to other fish. It alters their behaviour to divers in the water. Best to just kill them and either drop them or take them to the surface and turn them into ceviche for divers or feed DM's families. Yes, it is entertaining to divers and photographers, but I disagree with the practice.
I just returned last week with 25 dives. The DM's would brief us if we saw a lion fish let them know. They killed everyone they saw and would break them up and feed them to snappers, groupers, nurse sharks, morays, lobsters and even once a toad fish that came out of it's hole to eat it during the day. Some dives didn't see a one others the DM's killed up to 3.