OMG!!! They are so cute when they are babies.
My big puffer was really picky with eating, unless it was a clownfish. To keep the bioload down in my tank, I get the raw seafood mix from the supermarket. It has squid, cuttlefish, mussels, clams, octopus and prawns or shrimp in it. I put it all in my blender with a few cloves of garlic, selcon and RO water. I blend it up (fried my blender the last time), put it out onto a cookie sheet and freeze it. I then cut it into cubes and Griffie (my puffer) goes nuts for it.
He devours it and would eat himself to death if I kept feeding him since he is bottomless. All the other fish come and wait for him to eat since he chows it down and tidbits blow out his gills. Because the uneaten portions melt and go into my overflow, into filter socks and the skimmer, my tank stay very clean. I have no spikes in ammonia or nitrates at all anymore.
When I tried prawns or shrimp he did not care for it and they would be rotting on the bottom of my tank. This has worked very well for me and Griffie and he is very healthy and robust. I don't know how well I am duplicating his natural diet but he is doing very well.
Good luck with your baby, he is adorable. I think GSP is right about the bite and perhaps he got it at the store prior to coming home with you. You may not have noticed it until now, since you have had a chance to admire him for awhile.
This is what you little baby will look like some day. My guy is huge and is about 9" long now. He has grown a little since I bought him. One of the pictures he has puffed up (my tang got in the way of the shot), and he does this whenever he has eaten something (snails) he shouldn't and needs to digest it.
