Livebearers (Guppy, Molly, Platy)

Viviparous fish are aquatic species that, unlike many other fish, give birth to live young that are already formed, instead of laying eggs. This method is rarer among fish, but it offers certain advantages for the survival of the juveniles.
Characteristics of viviparous fish
Fertilization takes place inside the female's body, where the eggs are retained until hatching. The embryos develop inside a special pouch, and once mature, the fry are born directly into the aquatic environment. This strategy allows young fish a better chance of survival, as they are immediately able to swim and avoid predators.