This is a strange tang. I got one for 4 years. It grew from 1.5 inches all yellow to an adult coloration tang with the trailers on the tail and everything. I have him in my 8 feet 450 g tank with 4 other tangs (Purple, Yellow, Powder Brown, Powder blue) He was the largest of all my tangs. For the last year or so, He did not do as well as before. He was fat, but once he become fully adult in coloration, he start to swim lots and pace the tank. He eats less and loose weight. He was still healthy, never got sick, and not too thin. I was going to remove him and donate him to the Texas State Aquarium, but their tanks were not doing well. They have to remove some of their fish and give these fish to a LFS, so I keep my fish. He was about 8 inches at the time.
IMO from this one experience, Acanthurus pyroferus requires large tanks. Their streamers and the sickle shape tails (develope as adult) are signs that they are fast opem water swimmers as adults. My fish almost reach full size from a small juvenile in my tank. I did not find that he is comfortable in my tank which was bigger, by far, than most home tank.
Minh
