How Black Mollies Mate

* Male displays to female. The male molly will display his fins and swim in front of the female. He may also nip at her fins or body.

* Female selects a mate. The female will choose a mate based on his size, color, and health.

Step 2: Mating

* Male inserts his gonopodium into the female's anal vent. The gonopodium is a modified anal fin that is used to transfer sperm.

* Sperm is transferred to the female's ovary. The sperm will travel through the female's oviduct and into her ovary.

* Eggs are fertilized in the female's ovary. The sperm will fertilize the eggs when they enter the ovary.

Step 3: Pregnancy

* Female's belly swells as she develops eggs. As the eggs develop, the female's belly will swell. She may also become less active and hide more.

* Female gives birth to live young. After about four weeks, the female will give birth to live young. The fry will be small and transparent. They will need to be fed special food and kept in a separate tank.

Step 4: Care for the fry

* Feed the fry small, live food. The fry will need to be fed small, live food, such as brine shrimp or daphnia.

* Keep the fry in a separate tank. The fry will need to be kept in a separate tank so that they do not get eaten by the adults.

* Gradually introduce the fry to the main tank. When the fry are about 1 inch long, they can be gradually introduced to the main tank.