The Life Cycle of Frogs By Nathan Cook

Overview From egg to adult, frogs undergo complete metamorphosis. There are four distinct phases in a frog’s development. The beginning of the life cycle begins when two adult frogs copulate. The spermatozoa from the male combines with the oocytes in the female to create ovum, which is then laid as eggs.

Eggs Frogs lay their eggs in the water. As frogs are amphibious, they are able to live both on land in water. However, when tadpoles hatch they only have gills and need the water to survive. The eggs clumps together in a mass that is called spawn. Usual time for eggs to hatch is one week from fertilisation, depending on the species of frog. A general rule of thumb is the larger the adult frog is in a species, the larger the amount of time it takes for the eggs to hatch.

Tadpoles eat algae in order to gain nutrients and survive. Tadpoles remain the same for an average of four to six weeks before they begin to undergo metamorphosis. During this stage, tadpoles are likely to be eaten by various fish, birds and water insects, but are generally safe from land animals. Metamorphosis begins when there is increased thyroxin in the tadpole’s blood.

Tadpoles With Legs During this stage of development, tadpoles begin to grow their legs. Skin begins to grow over the tadpole’s gills. Eventually, this skin will complete cover the tadpole’s gills which will cause the animal to begin breathing air. This stage takes place around six weeks after birth.

Froglets Most tadpoles become by twelve weeks old. The froglets are almost ready to leave the water. Froglets now have a developed mandible that will allow them to eat the same diet as frogs – small insects. Many of froglets features have changed and will continue changing. Their tails will continue to shrink and their legs will continue to develop. Their eyes have also reposition to allow better vision on land. Eventually, they will move onto the land as frogs.

Frogs Between twelve and sixteen weeks, the froglet will develop into an adult frog. The frog’s diet has changed from being herbivorous to omnivorous. Living on land, frogs now have a different set of predators. Eventually, all frogs will return to the water to reproduce and begin the cycle again.