how can u tell if a platy is male or female?

Answer 1

The real trick to sexing livebearers is the paired anal fins: in males they are noticeably pointed, and rather thin, whereas in females they are quite rounded, fan-shaped almost. Also, males will tend to have slimmer bodies, whereas females appear to have a fatter abdomen and a somewhat wasp-waisted shape.

Answer 2

Have a look at the anal fin, this is the one at the bottom of the fish just before the tail. The male has a thin pointed fin called the gonopodium which is used in mating to deliver the sperm. The female has a triangular fan shaped fin.

Answer 3

the female fish looks like two wings under the stomache while the male fish will look like a long fin under the belly which will extend forward.