Animal Life Cycles

Invertebrates begin life as an egg, hatch into larvae, develop into a pupa, and finally grow into an adult.

Fish have a six-stage life cycle, starting as an egg, hatching into larvae, becoming a fry that feeds independently, then a juvenile, an adult capable of reproduction, and finally spawning to produce fertilized eggs.

Amphibians start in water as an egg, grow into larvae (like tadpoles), develop gills as young amphibians, and reach adulthood when they can reproduce.

Both birds and reptiles lay eggs, with embryos fully developing inside before hatching. Newborn birds rely on parents for food, while reptiles are left to fend for themselves.

Mammals are unique as they do not lay eggs. Instead, the fertilized egg develops into an embryo and then a baby inside the female. The baby progresses through childhood, adolescence, and reaches adulthood when able to reproduce.