I was at the pet shop and talking to the marine expert. I was looking in the brackish tank that had a GSP puffer a ruby scat , 2 green scats, and 3 silver scats, and a pea puffer. the pea was cheap at $9. I tell the marine expert, and say that I was thinking of putting the small yo-yo loach in my 10 and through the puffer in with a few more small fish. then he says "well the pea is brackish but the others can be acclimated possibly." I say that I read that they are fresh, but he said "it probably said that it can work in fresh, but is brackish." I tell him that it is a FW puffer. He said there is no such thing as a FW puffer and that every puffer is found in at least slightly brackish water naturally. Then the guy dares me to name 1 puffer that originates in FW. I did'nt even have to think. Tetraodon Mbu is what came out. He started reseach on it on the computer. I had to get home, So I said that he should find several links supporting what he says and I'll find several link of my own.