Fish breathe underwater, which means they take in oxygen from water instead of from the air like you do. While a fish swims through the water, its gills absorb the oxygen in the water and pass it through its bloodstream and membranes.
How Tadpoles Breathe
Before they get big and leave the water, you can watch how tadpoles breathe in this frog activity. All it takes is a steady hand and some patience.
What You'll Need:
- Clear plastic cup
- Pond water
- Food coloring
How to Watch Tadpoles Breathe:
Step 1: Look in shallow ponds for tadpoles. Catch one good-sized tadpole and put it in a clear plastic cup of pond water.
Step 2: When the tadpole is sitting still, fill an eyedropper with food coloring. Slowly and gently lower the tip of the eyedropper into the water until the tip is close to the tadpole's mouth. You may want to practice with a water-filled eyedropper until you can do this without disturbing the tadpole.
Step 3: Once the eyedropper is in place, slowly squeeze out one drop of food coloring into the water in front of the tadpole. Slowly and carefully remove the eyedropper and closely observe the tadpole. If the animal hasn't moved, colored water will soon stream out from the gills on the sides of the tadpole's head.
The tadpole breathes by drawing water through its mouth and passing the oxygen-rich water across gills that contain small blood vessels. The tadpole takes in oxygen from the water and releases carbon dioxide. The water passes out of the gill openings.
In the next craft you'll get a chance to watch grown frogs in action.