Hi! One of my female platys has been breathing heavily and not swimming much all day. She did eat, but afterwards she just went back to the bottom of the tank. She has no visual signs of illness on her scales. She can swim. I moved her to a smaller tank so I could monitor her. She could be pregnant. It is hard to tell because she’s very small. All of my other fish are fine. A while ago, I had a female molly who was doing the same thing. The molly was fine after a few days. I never saw any fry when that happened, but I hadn‘t been looking. She seems to be swimming a bit more in the smaller tank, but she is still breathing very heavily. The only other fish in the tank with her now are two platy fry which will be released into my main tank very soon. What should I do?