I have 2 apistos in a 20 gallon long. The male is fine, but I noticed that my female has an unusually large stomach and she keeps either swimming at the back of the tank near the surface, or lies on the gravel. Wheras previously she spent most of her time in her cave or midlevel. THe male occassionally swims up to her and backs up into her. Is the bloating a problem? If so, what should I do about it?