Naso Tang eating question

[Ruth]

I purchased a large (probably 8-9") Naso tang at the beginning of December. So far the only thing I can entice him to eat is Nori - loves it - grape calurpa - I have just about run out - and some chaeto. He is not at all interested in any meaty foods or formula 2 flack or pellet and in fact only began really tearing into the nori about one and half weeks ago. I have never had a tang before that wouldn't eat just about anything you put in the tank with gusto.
He appears to be healthy - no spots at all and nice plump belly bright color (for a Naso) and very active. Do you think he is ok on mainly Nori or any suggestions on getting him to take some meaty foods. I have tried mysis shrimp, brine shrimp and homemade goop. Even cyclopeeze doesn't really interest him. I have soaked all food in garlic and garlic and selcon.