The life cycle of frogs is a fascinating journey from birth to metamorphosis and finally adulthood very unlike its youth. There are almost 5,000 recognized frog species in the world today, with the Goliath frog measuring over a foot long and weighing over 6 pounds, while the gold frog is barely 1cm long (about the size of a dime). However, even with all their differences, there are a few things that are true about all frogs.
Frogs are amphibians, meaning they live both in water and on land. They begin their lives in water, and need to stay near water to reproduce, but they can be found in almost any environment all over the world. You’ve likely heard them croaking or seen one jumping on the shore of a pond. You may also be familiar with tadpoles, little fish-like things that live underwater and swim around in ponds. What you may not know is that tadpoles and frogs are the same creatures, just at different points in their life cycle. The life cycle of a frog consists of several stages from egg to full grown adult frog. We’ll go through each stage below, but first, we need to talk about life cycles.
What is a Life Cycle?
‘Life cycle’ is a way to talk about the stages of growth and life that animals go through. All animals have life cycles, from birth to death and the birth of a new generation. That’s where the ‘cycle’ part of life cycle comes in. It refers to the repeating, cyclical nature of animal life.
Many animals experience life cycles in which adults give birth to babies that look just like smaller versions of themselves. Humans, cats, dogs, elephants, snakes, alligators, birds. Many animals’ life cycles operate this way, but there are other life cycles in which animals change significantly from birth to adulthood.
When an animal undergoes a significant change of form during its life, it’s called metamorphosis. Animals who undergo metamorphosis can often be mistaken for completely different species, even though they are the same animal. These animals include caterpillars that turn into butterflies and tadpoles that turn into frogs. So now let’s talk about the life cycle of a frog.
The Life Cycle of Frogs
Frogs have several stages in their life cycles. They first start as eggs, which are fertilized during the breeding season. Once they hatch, they become tadpoles, which grow into young frogs and finally adult frogs before breeding and having baby frogs of their own.
The breeding season for frogs depends on the climate of their home. In temperate climates, the breeding season is during the spring, and in tropical climates it occurs during the rainy season. Male frogs who are ready to breed croak loudly to attract females. If a female likes the male’s croak, she will choose him for a mate.
Life fish, the eggs are fertilized outside of the female’s body, but a male and a female still work together. The male grabs onto the female’s back and fertilizes the eggs as she lays them.
Frogs lay their eggs in water, usually among vegetation which can keep the eggs safe. The eggs are laid together in large groups called spawn. At this point, many adult frogs leave the eggs to develop and hatch on their own, but some stick around to look after the eggs until they hatch. As the eggs develop, the yolk grows into a tadpole until, after one to three weeks, it hatches and a little tadpole swims out into the water.
Tadpoles are what we call frogs larvae. They are at this stage very fish-like, with gills to breathe underwater and a long tail for swimming. For a week or two after hatching, tadpoles move very little. Instead of swimming around and eating, the new tadpoles get nourishment by absorbing the remaining yolk from their egg. This gives them time to grow strong before venturing out into the pond to find their own food.
Once a tadpole swims away from its egg, it feeds on algae and vegetation either by filtering it from the water as they swim or biting bits of vegetation from plants growing in the water. While still a tadpole, the frog’s body is developing, growing lungs and eventually growing legs while its tail shrinks. As it grows, it starts eating larger pieces of vegetation and eventually insects.
- Young Frog
As the tadpole grows legs and its long tail becomes shorter, it matures into a young frog. During this stage, the tadpole stops eating and lives off the nutrients stored in its tail. Skin also forms over the gills during this stage as the frog transitions from life in the water to life on land. Once the tail is fully gone and only a little stub is left, the tadpole is considered a young frog. This is usually about 12 weeks into the life cycle of the frog. At this point, the frog leaves the water and hops onto dry land for the first time.
- Adult Frog
Although considered a frog by about 12 weeks into its life cycle, the young frog will continue to grow and develop for about 2 – 4 years. At this point, the adult frog is ready to lay or fertilize eggs and begin the life cycle of other young frogs all over again. The frog will live for several more years, its final age determined by species and whether it’s lucky enough to avoid predators.
In the end…
Frogs are truly fascinating creatures with a unique life cycle of birth to metamorphosis and finally adulthood very unlike its youth. As a baby tadpole, frogs have gills and can only live underwater, and as adults, they have lungs and can only breathe out of water. They still live nearby their ponds though, swimming and hopping and croaking until it’s their time is over, and the life cycle of frog’s begins again with a whole new generation of young tadpoles.