The puffers at walmart are Green Spotted Puffers. I wouldn't get them there anyways because those are usually sick. Not a hard mistake to make. When I went out to get my first dwarf puffer a LFS in LA sold me a GSP and it promptly died.
There are two "true" freshwater species, but I can only find dwarf puffers locally. See below for a link to the species of freshwater puffers
Last edited by dubels; 07-03-2012 at 04:15 AM.