Life Cycles

Learn about how small eggs turn into adult frogs!


Life-Cycles of Frogs

Click between the tabs below to learn about the life-cycles of different frogs!

Below is a drawing of the life-cycle of the common frog. The Latin name for this frog is Rana temporaria. During its life cycle, the common frog physically transforms from a hatchling tadpole to a fully grown frog! Another more scientific name for this process is metamorphosis, which translates to “changing shape”.

In our lab, we focus our studies on the African clawed frog. The latin name for this frog is Xenopus laevis. Xenopus have very similar life-cycles to the common frog, but there are a few important differences. Xenopus tadpoles eat different food to common tadpoles and adult Xenopus frogs are also fully aquatic!

from Hachoumi & Sillar (2020)

Detailed Life Story of the Common Frog

Click on the images below to follow the life-cycle of the common frog!

Now let’s summarise what we’ve just learnt!

You can also watch this video which summarises the metamorphosis of a frog!


What About Other Frogs?

The American bullfrog (Latin name: Lithobates catesbeiana) has a very similar life-cycle and metamorphosis to the common frog, but not all frogs develop this way.

by Michael Nusbaum

The Puerto Rican coqui tree frog (Latin name: Eleutherodactylus coqui) develops completely in its egg! This is called direct development1. Unlike the common frog, they hatch as fully formed froglets, often with small tails. Watch these two videos below of coqui frogs hatching!

Because of this direct development, their eggs have to be much larger than the eggs of the common frog, so that they have enough nutrients to fully develop before they hatch. It also means they are very small frogs. Look at this adult coqui frog- it fits onto a US penny!

by California Department of Fish & Wildlife

So-called marsupial frogs have the biggest eggs of all the frogs, with eggs measuring up to 10mm in diameter. Unlike other frogs, mother frogs have a pouch on their back where the eggs develop1. You can spot a female marsupial frog if you see little eggs or tadpoles on a frog’s back!

By Eldelcio Muscat

Darwin’s frog (Latin name: Rhinoderma darwinii) is a small frog native to Argentina and Chile with an especially unique life-cycle. After the male and female have mated and ferlitised eggs hatch into tadpoles, the male frog swallows the young tadpoles! He places them in a special pouch in his throat called a vocal sack2. After the tadpoles have fully developed into little froglets, the father has to spit them out! This is where this frog has gotten its nickname as the ‘vomit frog’. Watch the video below to see this unique frog in action!


Quiz Time!

Results

We hope you now know more about the life cycles of tadpoles! Click here to explore more topics.

 

#1. What is the scientific name of the process of when a tadpole changes into a frog?

#2. What is the first step in the common frog's life cycle?

#3. When tadpoles first hatch, how do they swim through the water?

#4. Click on the image of a froglet.

#5. What is the name of the frog that can fit onto a penny when it is a fully grown adult?

Finish

Fun Activities

Click through the different tabs below to see the different fun frog activities we have for you!

Do you want to see how tadpoles develop in real-life? Click here to download a life-cycle diary that you can fill out as your tadpoles grow!

Listen to a song about metamorphosis by the Singing Zoologist! See if you can match the stages we talked about above to his lyrics.

Click here to download a colour-in activity of a frog.

Watch the video below to see how Samiah Rose tracked her tadpoles’ development into frogs, and maybe you can try making your own video too!


Remember to attribute photographs, videos or work where appropriate! This is not needed unless used online, but if you’re unsure please refer to the creative commons licence rules. For academic references and media credits of the images above, please refer to the next page.

The Digestive System


 

The digestive system is modified to account for the change of the herbivorous diet of the tadpole to the carnivorous diet of the frog.

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The Skin


 

The skin adapts for the change from a purely aquatic lifestyle to an amphibious lifestyle.

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The Reproductive System


 

The urogenital system develops to allow for reproduction in adulthood.

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The Skeleton


 

The skeletal structure develops to accommodate the change from tail swimming to using legs to move around. The skull also needs to be remodelled for a frog's change in vision.

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The Nervous System


 

A tadpole sees from eyes that are positioned on opposite sides of the head. During metamorphosis, the optical nerves develop to accommodate a frog's binocular vision, where the eyes are positioned at the front of the head.

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1. Mating and Laying Spawn


 

Male and female frogs go to ponds in the winter. They mate in the spring, and the female lays big clumps of eggs.

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2. Frog Spawn


 

Frogs eggs are called frogspawn. Each round black egg is about 1 mm wide and is surrounded by a blob of jelly. Other animals produce spawn as well, which you can look at here.

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3. Maturing Frog Spawn


 

After a few days, the eggs begin to grow into tiny tadpoles inside the jelly.

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4. Hatchlings


 

Then the tadpoles hatch! They are about 5 mm long and they can’t swim (yet). They can bend their body from side to side using special muscles along their trunks and tails.

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5. Young Tadpoles


 

When their tail is big enough, they swim off into the pond to start to feed. At first they have gills (the pale protrusions from the head region in the left photo) so they can breath underwater like fish. Young tadpoles feed by grazing the surface of pond weeds and also eating tiny floating plants called algae.

Click here to play a tadpole feeding game called Taddypole!

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6. Maturing Tadpoles


 

Later they develop lungs and can swim up to the surface of the water to breath. The gills are absorbed back into their bodies and eyes develop. Older tadpoles are then able to feed on small animals like young insects.

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7. Mature Tadpoles


The next stage in development is to grow back legs. Tadpoles during this stage need to eat meat in order to get the proper nutrients to grow.

If you are looking after tadpoles, be careful as they can eat each other if you don't give them meat to eat! Click here to learn more about how to look after tadpoles as pets.

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8. Froglet


Finally, tadpoles grow front legs and their tail shrinks until it almost disappears. This is when they climb out of the pond and start living on dry land. Small frogs are commonly called froglets.

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9. Adult Frog


The little froglets will stay by the pond and slowly grow over the summer, eating small insects and worms. They will hibernate just like other adult frogs in damp spots near ponds from autumn until the next spring.

After four years, the new frogs will become adults and will be ready to mate and begin the cycle again.

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Copy - 9. Adult Frog


The little froglets will stay by the pond and slowly grow over the summer, eating small insects and worms. They will hibernate just like other adult frogs in damp spots near ponds from autumn until the next spring.

After four years, the new frogs will become adults and will be ready to mate and begin the cycle again.

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Desert Habitats


Desert habitats are the driest habitats in the world. Most people only think of very hot habitats as being deserts, but cold habitats can be deserts as well! Animals and plants that live in deserts have the ability to survive on very little water and animals can control their body temperatures so they stay at the right level.

 Some examples of plants and animals that live in deserts are cacti, the desert tortoise and the artic fox.

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Coral Reef Habitats


Coral reefs are found in warm tropical oceans all around the world. Coral reefs can be found in both shallow and deep water and take hundreds of thousands of years to grow! They provide food and shelter to many fish and other animals, making them habitats that are home to so many different types of life.

Some examples of plants and animals that live in coral reefs are the sea star, sea grass, the octopus and clown fish.

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