Who says how to tell the difference between men and women fighting fish in China?

If you don't need pictures, there are two kinds of China: fork tail and round tail. The dark fish is male, the shallow fish is female, and the older fish is female. The tail of male fish is very long, and the fin of female fish is shorter than that of male fish. It is not easy to see them below 3 cm, but above 3 cm, the adult male fish with forked tail is like a fork, and the female fish with forked tail is like a scallop.