I've got a small (maybe 8" across) long tentacle anemone in a 10gal with a hosting Clarki clown.
It's got 130w of 50/50 lighting and currently it's got corals, but that's going to be changing very soon.
In his "travels" he's come in contact with several types of corals, except for one, without any ill effects.
The one red rhodactis mushroom that's in there reacts badly to being stung.
Twice it's happened and both times he's shriveled up and expelled all of his "intestines" like a tangle of white thread.
Both times tho he's recovered within 24 hours of being moved out of the "danger zone".
Like I said, most of my corals aren't bothered by being touched by his tentacles, but probably this weekend I will be moving them all to my big tank anyway and just leaving the anemone and the clown in the 10gal.
"Damsels are the yapping, ankle-biting chihuahuas of the ocean.
They have no concept of just how small and annoying they really are."