what do baby yellow tangs look like? They is one at the local LFS that is about the size of a loonie, but it is almost a brownish color? not yellow at all? Are they this color when young??
I think Ernie's right, it's probably a carribbean blue tang. Small fish like that aren't exceptionally hardy, you'd probably want something with a little more meat on it's bones.
A loonie is a canadian coin worth one dollar. It has a loon on on the tails side. A twoonie is a candian coin worth two dollars. They are roughly the size of a Susan B Anthony dollar.