I certainly have to comment on this one, I also have a snapping (or 2) mantis or something. I believe I got a glimpse and it was very small, about .5" or so long. And my dilema is very similar. The rock I think they are in has some nice corals growing as well on it. One side has a green mushroom that has already dropped twice and is in the process of a third drop. The other side of the rock has a very early stage of either a torch or frogspawn. Too little to tell now, but it is so awesome. I have also recently discovered a single snake polyp that opens up a few hours a day on the same rock.
But I am not down any fish, but I have had a few peppermints disappear... but I do have a few hitch hiker crabs as well. So who knows anymore