We've had the mandarin a good 8 months now. We actually had it with a scooter blenny that up and died on us. I know the general consensus was lack of appropriate food but the blenny died after about two years give or take some months.
The mandarin and blenny both we got extremely lucky on. I'll preface this by saying, I maintain a mini-reef to keep my girlfriend happy while I have the pred tank. She came home with one two years ago and the other eight months ago.
Back to the point. We're very lucky, both ate prepared/frozen foods. The begining of both started with supplanted copepods removed from the back via turkey baster plus the bottled arcti-pods? tiger-pods? the one that isn't alive. Since the rest of the fish would go crazy with the smell of food in the water we'd add the mysis or brine at the same time. I played with the ultra-fine micro foods but no one ate them and they'd murk up the water. After a week the scooter ate both live and frozen brine and mysis, the dragonet picked up after about a month. Not usual results and the water changes were hell, not to mention the dismay resulting from, "These are very delicate fish sweetie, at the first sign of problems I'm taking them back and until you've done your research you will ask me whether or not things go in the tank." . Luckily fish are about the only things I get heated about and I'm not nearly so egotistical now. She's done the research and tells me why I can't add fish so we're all happy.
Sorry, did I make a short story long again? We're extremely lucky that they both accepted prepared foods. Both had the tenacity to eat live brine (ever seen a dragonet stalk something? CUTE) and never looked thin. I wouldn't suggest though, at least not for beginners.