I recently placed a regal tang and velvet dottieback in with 2 false percs (nemo), a yellow tailed damsel, and a yellow wrasse. At first I thought the damsel was going to be a little irritated but has taken to both of his new tank mates. Up until last night I thought everyone was getting along. I did a water change in the 125 they are in, and afterwards the larger of the percs (I assume the female) started chasing the regal. Both the regal and the nemo are about the same size. The nemo doesnt nip at the regals tail or fins, she opens her mouth and appears to "mouth" him on his side....its weird. You can tell she is trying to chase him off from her area but didnt do this until last night. I turned the lights on this morning and she seemed a little better with the regal so far. Also appears she doesnt want the regal anywhere near her man!! Anyone have any thoughts on this? I assume this is temporary and will pass? Are they just establishing a pecking order? I just thought it weird that the damsel is ok with everyone but the nemo isnt.....