Never done it so can't say first hand, but just my thoughts. Could they live in it? Probably could, but my concern would be puncture from fish/fins, or heater/filter wearing a hole in it. Those little inflatable pools are not made all that durable.
IMO I'd look for a hard shell outdoor pond before an inflatable. You can get them locally on CL for $50 or there abouts for a decent size one.