Danios (6, not sure if m or f), platies (5, not sure if m or f), and guppies (4 m, 2 f)... I know it's general, but I didn't know if there was a generic way to tell if fish are pregnant, other than bigger stomaches.
I did quarantine a female guppy because she looked a lot bigger than when I first got her. Her swimming is quite frantic, her gravid spot is dark, but I never did a full check to see if it was there when I got her. Any advice?