A little update. At the beginning of August my (5 year old) volitan lionfish went on a hunger strike and lost all of its appetite. By the end of the month it was dead... I looked around on reefcentral to try and find answers but the best thing anyone could come up with was spontaneous fish anorexia. So I'm swearing off big lions for a while until I have a chance to upgrade to a larger tank in a few years.
In the mean time our LFS has had this little fu manchu for months and they've weaned it over to frozen food. It takes both frozen silversides and krill off of the end of a feeding stick and is almost always out and viewable.
