I had an 8 inch Clown Trigger, and it was not aggressive to fish in the tank (well sort of but not to the point of killing) but if I put my hand in the tank, he was on the war path. That thing wanted to kill me for some reason, so it would take two or three people any time I wanted to do anything in the tank. One (me) with hands in the tank doing maintainance, and the other two are on net duty. I don't have him anymore because my tank crashed while I was away on vacation and all of my fish went to fishy heaven (lol) but I "promise" I really miss that fish (well sort of haha).