Mine is. After watching some videos on keeping multiple Tangs and adding new ones, I decided to move a Yellow Tang from QT to the display. The display already had a White Tail Bristletooth and Purple Tang. The minute as the Yellow went in, the White Tail went after it aggressively. Impossible to get either of them out without a tear down. The Yellow deployed his scaple in defense and the White Tail essentially scalled himself trying to kill the Yellow. The White Tail was found dead in a cave a couple days later. Not a good trade off as it took me quite a while to find that White Tail and he was perfect and $190. The Yellow and Purple seem to be tolerating each other for the most part so far.