Wednesday, September 17, 2008

He's got legs and he knows how to use them...

A miraculous thing happened overnight in our eco-unfriendly Styrofoam tadpole habitat - some of the little tadpoles grew legs! I know that tadpoles go through the exciting metamorphosis into frogs on a daily basis all over the world, but to witness it happening on our own patio is really quite cool. I'm so happy that our boys are learning about this process and seem quite intrigued with the whole thing. It's a great way to open up the dialog into evolution and how all creatures evolved.
To give the boys a closer look I dip a glass into the water to scoop out some tadpoles, let them oogle for a minute or two and dump them back in. I figure the tadpoles are none the worse for wear and if they'd been left in the wild they'd probably be bird food by now anyway.

The boys are fascinated with the two tadpoles that have tiny little legs. They noticed that these tadpoles are also taking breaths of air from the surface instead of using their gills to breathe oxygen from the water.
I learned from our tadpole literature that tadpoles breathe through gills. Lungs develop around the time of leg development and tadpoles at this stage of development will usually be found near the surface of the water where they breathe air. During the final stages of external metamorphosis, the tadpole's mouth changes from a small enclosed mouth at the front of the head to a large mouth the same width as the head. The intestines shorten to make way for the new diet. It's amazing to think that all this is going on in these tiny little creatures on the patio.

We still have some little tadpoles that are behind the ball in the metamorphosis game. They're much smaller and show no signs of legs. It's actually good because we can compare these tadpoles with the new "leggy" tadpoles in a little preschool game of compare and contrast.
We also put a large landscaping rock into their habitat so the new leggy tadpoles will have somewhere to perch. And last week I hooked up an old aquarium pump I found from my college days and I run it for an hour or two a day to pump some extra O2 into the water. (I used to have a 1-gallon fish tank where I had two pet goldfish that lived for about 4 years. I had no clue that $3 goldfish could last that long, but they did. Their names were Chauntecleer and Pertelote, from the two chickens in the Nun's Priest's Tale from Chaucer's Canterbury Tales.) You should be able to click on any of the photos above and get a close-up view of the tadpoles. You should just be able to make out the legs on the 1st, 2nd and 5th photos. The 3rd and 4th photos are the younger ones. They're tiny and quite transparent, but they're there! I'm not on a quest to find out if tadpoles experience any pain from the metamorphosis process… just out of curiosity…does it hurt to grow legs?

1 comment:

Caroline said...

Soooo freaking cool! Will have to troll the farm pond for some 'poles of our very own!

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