SirMinion is of course correct, that there are several possible species in the genera Chonerhinus and Auriglobus. I, for one, find it very difficult to distinguish these at genus level, let alone species. You need to count the rays in the fins... not easy when they're alive and swimming about. Otherwise they are virtually identical.
Either way, these remain violently unpleasant fish, so whatever the fish, you're going to end up with just one, in its own tank, with no tankmates. I suppose a low salinity (SG 1.003) would be safe enough even with the freshwater species and perhaps enough for the brackish water ones. You'd have to see how the fish behaves and what its health is like before deciding whether to raise or drop the salinty.
There are very few fish that I would advise against keeping, but this is one of them.
Cheers,
Neale