I guess it depends of the fish, the tank, and the other fish. I have had absolutely no problem with sixline, and the current one is my third one. They need a lot of rocks and hiding places, as they continuously weave in an out of the rocks. But I never saw any aggression from them.
On the other hand, I had a lot of aggression from my fourstripes damsel. So I am reluctant to ever buy a damsel again. I still have it, must be around 12 years now, and the problems are gone, but it did kill one chromis and possibly a newly introduce coral beauty.
On the other hand, I had a lot of aggression from my fourstripes damsel. So I am reluctant to ever buy a damsel again. I still have it, must be around 12 years now, and the problems are gone, but it did kill one chromis and possibly a newly introduce coral beauty.