The interesting thing for me is that the fish looks so good after the six years in your tank. I've have a semilarvatus since 1999, but it looks a bit "tattered" and shows some artifacts of being in captivity - poor color, stunted growth, etc.. Yours looks like it just came from the reef!
Thanks. This fish has held up very well. Bright, active. Really a model citizen from day one. There have been a couple times where my tank has been a bit neglected and the parameters have gone south for a spell, but he has toughed it out.