What kind of puffer is he? I have a golden that didnt eat ANYTHING for a month. others that were pigs when i dropped them in the tank.
I have never had a puffer, ( owned 7 species ) that liked silversides, and only the big ones touch squid. I feed mine combinations of pellets, krill, cockle, mussels, prawns, formula 1&2, PE mysis shrimp, and occasionally gut loaded feeder shrimp.
Some of my puffers eat all of that, some just a couple things. I like to offer a variety of foods. My biggest, all gold puffer, 12 " eats ONLY pellets. They have to be brown colored pellets too! He wont touch green spirulina pellets, very picky.