Frog ‒ Life Cycle

A frog’s life begins with the development of a fertilized egg. The egg is typically transparent, with a distinctive darker mass in the center, which contains cells that start to multiply and form the future embryo. As the embryo develops, organs and structures such as gills begin to form. With a defined head and tail for movement, the embryo breaks free of the egg and officially enters the larval stage. At this point, the larvae are known as "tadpoles" or "pollywogs." Tadpoles breathe through gills and begin feeding, developing simple, toothless mouthparts adapted to consume almost any organic material. As the tadpole grows, it enters the phase known as metamorphosis, undergoing a near-complete transformation. During this stage, hind legs and lungs develop, and the gills and gill pouch disappear. Soon after, the front legs emerge, and the lower jaw transforms into a larger, stronger mandible. The nervous system further develops, and the eyes shift to a higher position on the head, with eyelids and associated glands forming. The skin thickens, becomes tougher, and skin glands develop. Finally, the tail is absorbed into the body. At the end of metamorphosis, the frog is semi-aquatic, capable of breathing air and dependent only on moisture for survival.