I have some platys in my tank at a ratio of 5:2 (F:M) for around 1.5 months and one of the platy looks quite boxy yesterday night. I have installed a tank divider with some sponge to separate it. When should I expect her to have fries?
You should keep an eye on this fish. The analfin is still V-shaped but pointy. I wonder if she's changing sex. That makes me also wonder if she's actually pregnant (could be the case but doesn't have to be) despite of the large belly. But just give it some time and see what happens.