Hi. We have three female bettas and have had them for several months now without any problems. They're in a 10 gallon tank with one dwarf frog. Recently, one of them has started acting strangely. Her gills are always fanned out and she usually rests at the top of the tank like up against the thermometer where she can take breaths. Rarely have we seen her swim around, and when she does it's just for a second and she's back to resting at the top again. It seems to me like she's having trouble breathing. The other two fish are fine and acting normally.