I have 2 yellow-tail damsels (they were my first) as I was told they were sturdy fish for a first timer. That is true but they are very difficult on other fish and on the tank. I had to separate them early on as one was a complete bully and had the other in constant hiding. The "bully" has been living in my QT ever since, which means, of course. I don't have a QT anymore. The other gets along with my other fish (1 flame angel, 1 true percula, 1 lawnmower blenny & 1 royal gramma). He and the angel vied for dominance but he, unlike the angel, antagonized the other fish, except for the percula who made friends with everyone. Several months ago, he banged is eye on a rock (probably while fighting the angel), had a pop-eye for a couple of weeks and now is blind in that eye. since then the angel is the dominant one and the other fish are no longer harried by the damsel. Above, I mentioned that damsels are hard on the tank. I say this because they like to dig holes by swooshing their tails in the sandbed. If you've placed your rocks on top of the sand this could cause them to shift and fall, potentially damaging corals, etc.. (luckily, my rock was inserted first onto the tank bottom, and the DSB placed in after). It also creates a mess in your filters with all the sand kicked up, not to mention ruining your carefully crafted tank design. If I had known then what I know now, I would not have gotten any damsels!! But if your determined on having one, do you want one of mine?