I have 4 damsels in a 55 gallon with a pair of Clarkii's. I got the damsels with the tank and didn't want to dump them at the LFS and the clarkii's were too large to stay any longer in the QT so I thought I would give it a shot and everyone established their territories. The yellow tails are the lowest on the pecking order, then the three stripes, and the clowns rule the tank. When the clowns are playing and venture away from their anemone, the stripes stay out and stay out of their way but the yellow tails hide. I have had no fighting at all. Honestly, I have really enjoyed watching this tank more than any of the others.