Reptile & Amphibian Forums

Ok, I know dragonets aren't gobies technically, but I figured this forum would be my best shot since we often think of them as such.
I've had an adult blue mandarin male in my tank for about 2 and a half months. He's a big beautiful specimin and seemed perky at the store. Since I brought him home I've never seen him eat...not even once! I've tried frozen brine, a Kent Marine phytoplankton mix, cyclop-eeze, live tigger pods, and algae pellets. My other fish, a fire fish and a small female green spotted mandarin, go crazy for all the above but the big guy won't touch it. I even bought a piece of live rock hoping it would bring in some tiny critters he could pick at, but little interest. I called the store I bought him from and they said they were mostly feeding brine shrimp, though they didn't remember the specific fish so they couldn't assure me he had eaten it for them either. He looks good color-wise and shows no sign of disease, but I can definately see the emaciation line running down his side and he pretty much just sits in one place all day staring into space, unlike the active and curious female. How can I get this guy interested in food and what food should I try? I feel like I've run the gamut here--frozen, liquid, solid, dry, live-- and done my best but I think he's still wasting away. Any suggestions?
Tank environment overall is in good health. I test weekly and pH, temp, salt level, nitrates and nitrites check out fine.
Thanks for any input.

I've never had a goby myself but I remember reading an article in a marine fish magazine that said to try and culture copepods ( a link to a good site follows, I use it to culture just to help keep my tank clean and because my blenny likes them) and that some will eat caviar.

http://www.oceanpods.com/faq.html#tips