I've found exactly -one- photo on this snail...strangely on Facebook.
http://photos-f.ak.fbcdn.net/hphoto...8858272217_296035512216_6819672_3180484_s.jpg
Under the name Miratesta celebensis. I've seen several discussions on the fact that its either threatened or endangerd, but it does appear to be freshwater and not brackish.
It is really quite stunning though. While I can't condone harvesting this snail due to its status, working on a breeding colony would be admirable.
http://zipcodezoo.com/Animals/M/Miratesta_celebensis/
This would seem to indicate that it comes from only 5 freshwater lakes. I would wonder if a Sulawesi shrimp set up would be good. They are in the "ramshorn" family of "lefthanded" snails. No idea on feeding. I would probably put in an established tank with a good bio film and MTS incase they turned out to be assassin like. (doubtful, but who really knows when the only picture seems to be on facebook).