Through the research, it is found that the most important feature of male and female guppies is the ventral fin. The ventral fin of male fish is relatively sharp, while that of female fish is relatively round. Besides, you observe the male and female guppies in the distance. You will find that male fish are generally smaller, but their body surfaces are brightly colored, and their tails are generally very large, drooping and brightly colored, and they look very beautiful and dazzling. Compared with the female fish, its body shape is generally relatively large, and its belly will appear very large. There are some black patches on the abdomen, and its tail is relatively small and symmetrical up and down.

Scientifically speaking, when the guppy grows to 1-2 months old, you can observe the difference and change of its ventral fins, and then you should be able to correctly judge the male and female of the guppy.