They come from Africa and usually small Juv show up but every once and a while you find an adult show up. They grow fairly fast and will change over from Juv color to adult over time but does take a while for the Blue line mask to fully come in. Very hardy Angel and usually eats just about anything.
You need to be careful when purchasing one as the Juv look a lot like Maculocus & Blue Face Angels Juv, which do come from the same area specially the Mac's. If you get a juv, with the yellow tail, make sure it has the invert white "T' around the base of the tail. If you get a completely Blue/Black and White Juv you'll still see the white "T' but it's hard to pick out. You'll then need to check the bars to make sure you getting a Chrysurus Angel.
I've had mine for a # of years and it has gone through the change from a Juv to the adult colors. It gets along with my other fish and Angel, Mac & Asfer, and does very well.
Price wise it's not cheap, but small Juv do show up at the on-line place for about $125-$150, with adults in the $200+ range. The problem is finding one as they're not always available but they do seem to be showing up more now a days.