1. Egg: Guppies are livebearers, which means that the female gives birth to live young rather than laying eggs. However, the guppy eggs develop inside the female's body before they are born. The gestation period for guppies is about 21-30 days.
2. Fry: Guppy fry are born very small, only about 1/4 inch long. They are also very translucent, and their internal organs are visible. Fry are helpless at birth and must rely on their parents for food and protection.
3. Juvenile: As guppy fry grow, they will begin to develop their adult coloration and markings. They will also start to swim more actively and explore their surroundings. Juvenile guppies are typically about 1-2 inches long.
4. Adult: Guppies are considered adults when they are about 3-4 inches long. They are sexually mature at this point and can begin to reproduce. Guppies can live for up to two years in captivity.
During their lifetime, guppies will go through several molts. Molting is the process of shedding the old exoskeleton and growing a new one. Guppies molt as they grow, and they also molt when they are stressed or injured.