Thanks to everyone for their help and support with this cute little guy. He's become a typical glutinous puffer and he'll eat just about anything that will fit in his mouth.
WARNING - If you don't like feeling angry, please don't read any further.
We contacted the store where we got this fish and asked if they had any new puffers. Their answer included two more Striped Burrfish just like the one we bought from them. We visited the store and sure enough, the

store bought two more Striped Burrfish. They were almost exactly the same size and in the same condition s the one the sold us. They couldn't take care of the one we bought, so why in the

did they buy two more?
As best we can tell they bought this fish in mid-February, and we bought it two months later in mid-April in a severely undernourished condition. The store discounted the price to 30% to get the sale because the fish looked like it was on death's door.
We did the best we could to help assure that the store knew how to treat and feed their two new Burrfish. The store owner was very interested in what we did to save the Burrfish they sold us, but we're not sure he'll be willing to put in the effort. With the one we bought it was the employees acting beyond the scope of their job's that kept this fish alive. We're very frustrated because buying the first Burrfish from the store seems to have been taken by the owner as a vote to get more.
Well, all we can say at this point is

!
Robert and Anne