http://www.thetropicaltank.co.uk/Fishindx/puf-asel.htm
"This puffer is more tolerant of its own kind than many puffers, so more than one can be housed in a tank together. If they are kept with other fish, then their companions must be chosen with care, as despite its relatively peaceful nature, this puffer may still fin-nip, particularly at feeding time. It may fight over pieces of food with others of its own species, but other than this they seem fairly oblivious to each other. "