Leaping into a Frog's World

Nothing beats watching your kids learn about something by direct observation. The wonder in their faces as they see a process unfold and “catch on" to principles that you have talked about is worth the time it takes to think about how to fashion the lesson! Along that line, in order to teach your children about frogs and their life cycle, why not let them actually watch a tadpole grow up?
To do this, find some tadpoles - either in a pet shop or at a local pond or creek - and set up a tadpole aquarium. This isn't  hard to do and pet shop personnel are often quite helpful with tips and advice. And, as your child watches the little critters grow from their early stages to adulthood, you can help him/her to understand what is happening by filling in some essential details.

Frogs are amphibians. This means they are cold-blooded vertebrates - vertebrates have a backbone; they have no scales and generally breed in water.

 

Eggs are laid into still waters where there are no strong currents to threaten their survival. To further ensure that individual eggs are not damaged, each female frog will lay a huge number of eggs in one session. She lays each egg on its own but the resulting batch of eggs will lie in the water in a big clump called spawn.

Even with all these safety precautions in place, the existence of a frog egg is quite precarious and few will survive to become tadpoles - the fish-like, infant stage of frogs.




About 6-21 days after the eggs are laid and fertilized, the tadpoles will be hatched out to live in the water. A new tadpole will eat the remainder of the yolk of the egg that it came from and then proceed to try to survive to adulthood - not an easy feat!

 

Young tadpoles have a mouth, poorly formed gills and a tail. They will try to stick themselves onto a water plant for protection until they become strong enough to swim away and look for algae to feed on. Once they can live freely in the water, they can be maintained quite nicely in a properly built aquarium. 

 

Tadpoles can be very sociable creatures, so maintaining more than one is quite feasible. (However, please limit yourself to two tadpoles for each gallon of water in the aquarium in order to give them adequate space.)

 

As time passes, your child will be able to observe four important changes in the growing tadpole. After about four weeks, the tadpole’s gills will be covered over with skin and breathing will begin to take place through the lungs. At 6-9 weeks, tiny legs will sprout on the tadpole, first in the back and then in the front. As this happens, a head will be easier to discern and the body will get longer.

 By about 12 weeks, the next step in frog development - loss of the tadpole’s tail - will be almost complete. (Interestingly, the tadpole will stop eating plants at this point. For nutrition, it reabsorbs its tail and that’s why the tail disappears!) 

 

 

The last step, seen at about 12-16 weeks, will be the conversion of our new frog from vegan eating habits to full-blown meat-eater - bugs should now be offered on the menu, please! The frog will now also be a land dweller and your aquarium should be equipped for this change.

 

By the end of four months, your child should be able to describe the full life-cycle of a frog. Here are some other frog-facts that can add depth to your child's understanding of this animal. 

 

Frogs have very special skin. Aside from keeping its insides together, the skin of a frog is used for taking in water and for breathing. Frogs do not drink the way we do - that is, they do not swallow water. Instead, they absorb it through their skin. This not only keeps them properly hydrated, but is also a way to transport oxygen into their bodies. 

 

 

This transport process supplements the oxygen intake by the lungs. Therefore, a frog needs to make sure it stays nice and moist! If water is not available - either through an in-ground source or through dew - frogs will bury themselves in moist dirt. In addition, frogs can produce a mucous over their skin to keep themselves moist and thus prevent suffocation. A frog sheds its skin at regular intervals - with some species of frogs, this may occur once a day - to maintain an outer layer of healthy, functioning skin. 

Different types of frogs have feet which are suited to their habitats and lifestyles. Tree frogs have sucker-like, sticky disks on their feet to help them climb. Other types of frogs have webbed feet which can help them either to swim or to make them buoyant enough to fly.

 

Some frogs have claw-like feet which are meant to help them dig. The hind legs of a frog are very strong and can help them to jump as far as twenty times their own length. (That’s like us jumping about 100 feet! Have your kids jump like frogs and measure how far they can leap - this may help them appreciate the distance achieved by frogs when they jump.)

 

Frogs have an interesting way of eating their food. They have long, sticky tongues that SNAP out, catch the prey and then roll back into their mouth. Frogs actually have teeth. These are tiny and cone-shaped and their function is to hold the prey in place until it is swallowed. 

 

A frog’s teeth can be found in a row at the front of the upper jaw - maxillary teeth - and on the roof of the mouth - vomerine teeth. Finally, if you’ve ever watched a frog swallow, you will have noted that its bulging eyes close and sink down into its head - these big eyeballs actually push the food from the frog’s mouth down into its throat. Whole! GULP!

 

So, have fun watching your child learn about the life-cycle of a frog first-hand. If you acquired your teaching tadpoles in a pet-shop, then you can now keep the frog as a companion for your kids for a few years. Fact: The average life span of a frog is 4-15 years. So, stock up on those bugs! Leap on! 

THANKS TO: www.sciencewithme.com