I would have take some pics that day except the wife had the camera. Like I said, I've never seen this since, but if I do I'll try to get some documentation.
I'm don't think the Chromis was actually picking anything off the Mandarin, but it was certainly acting interested in it. Hanging out really close to it and sort of circling it checking it out.
As far as new species I think I would like a psychedelic Chromis, but I'd not be to hot on an all green Dragonette.