Depending of the species of fish, determining the sex of a fish can be quite easy or almost impossible.

Determining the sex of the fish in your aquarium isn’t just important for breeding, but it can be important for determining the balance needed for your community aquarium as well. Live bearing fish are among the easiest of fish to differentiate sex. Guppies, Platys, and Mollies are commonly lumped into the category of being live bearing fish. Livebearers give birth, they do not lay eggs to be hatched. Livebearer males are usually smaller and more colorful than the female livebearers. Besides size and color, another differentiating characteristic is the anal fin. Both females and males have an anal fin, but the male’s anal fin is called a gonopodium. The gonopodium looks more clamped, flat, and elongated than the female’s anal fin. The female’s anal fin is much more noticeable and fan shaped. Pisces Reef Fish Emporium is here to help. We are a great resource.