How long does a molli fish stay preagant?

Mollies are not pregnant fish. They are actually livebearers, meaning that they give birth to live young that do not need to go through an incubating period in the mother’s body. Mollies are constantly ready to reproduce when the conditions are right, and as long as there are males present in the tank and no issues with water quality, they will continue to breed. The gestation period in female Mollies is usually 25 to 40 days, depending on the species and how well they’ve been cared for.