Life Cycles

Academic References

[1] Sillar, 2023

[2] Britannica, T. Editors of Encyclopaedia (2020, April 4). Darwin’s frog. Encyclopedia Britannica. https://www.britannica.com/animal/Darwins-frog

Media Credits

Life cycle banner – by Kendra Melville using Canva

Diagram of metamorphic stages of Xenopus tadpole – Hachoumi, L. and Sillar, K.T. (2020). Developmental stage‐dependent switching in the neuromodulation of vertebrate locomotor central pattern generator networks. Developmental Neurobiology. doi:https://doi.org/10.1002/dneu.22725.

Rana temporaria mating in pond – by Thomas Brown

Rana spawn – by Alan Roberts

Rana embryos – by Alan Roberts

Hatchling tadpoles flexing – by Alan Roberts

Young tadpole (Rana temporaria) with gills visible – by Lia Gilmour

Young tadpoles – by Markus @ Thinkaholic

Wood frog tadpole with back legs – by NatureNorth

Froglet – by Steve Byland

Adult Rana sylvatica – by Oh Weh

Life cycle of a frog diagram – by Kendra Melville (using photos credited above)

American bullfrog – by Ryan Hodnett

Coqui tree frog – by California Department of Fish & Wildlife

Marsupial frog (Gastrotheca cornuta) – by Brian Gratwicke

Pages: 1 2

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.

This will close in 0 seconds

The Skin

 

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

This will close in 0 seconds

The Reproductive System

 

The urogenital system develops to allow for reproduction in adulthood.

This will close in 0 seconds

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.

This will close in 0 seconds

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.

This will close in 0 seconds

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.

This will close in 0 seconds

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.

This will close in 0 seconds

3. Maturing Frog Spawn

 

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

This will close in 0 seconds

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.

This will close in 0 seconds

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!

This will close in 0 seconds

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.

This will close in 0 seconds

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.

This will close in 0 seconds

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.

This will close in 0 seconds

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.

This will close in 0 seconds

Trial content.

This will close in 0 seconds

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.

This will close in 0 seconds