Hello all. It appears that there is some confusion as to what species of puffer Wal-Mart carries and as to what type of water (fresh or brackish) the “green spotted puffer” needs. There are three types that are very similar. Tetraodon Schoutedeni, Tetraodon fluviatilis, and Tetraodon nigroviridis. The problem is that Wal-Mart does not identify their fish by the definitive Latin name. But they can be discerned by the shape and some tell tale spines on the belly of the fish. The T. Schoutedeni (aka: spotted Congo Puffer, has a “club-like” shape to its body. In addition, it is the only one with two backward pointing spines on its belly. Its not a green as the other two and has kind of brownish background to its spots. The T. fluviatilis (green Puffer) has a more torpedo shape to its body, longer sloping head and back region. Kind of elongated. The T. nigroviridis (spotted green puffer) this is the most common one to be assumed as the fish in Wal-Mart , is pretty much spherical, like a globe or balloon. And it tends to have smaller dots. In that the t. Schoutedeni is purely a freshwater fish from the Congo River, that forms the Malebo pool (formerly Stanley Pool) near its terminus. Give it no more salt than any other freshwater fish, or it will die. I have killed my share (one) due to this confusion. Good luck to you all…….