Nature Notebook – Frog Eggs

It was bound to happen. When you allow a male and a female frog coexist in the Butterfly House pond, you will eventually see eggs.

Our froggy inhabitants are both on the young side. We knew the male was of breeding age because he has a yellow chin and produced the advertisement call. Our female is much smaller. Consequently, her egg clutch is small. Larger females can lay up to 3,000 eggs at once. The one in our pond seems to only have about 100.

Green frog eggs usually use emergent vegetation (plants with leaves above the water surface) to anchor their egg masses. However, if a frog is in a shallow pool (e.g., the Butterfly House pond) then the female will spread the eggs as a film on the surface of the water. Biologists think this may be an adaptation to provide the eggs with a more oxygenated area to develop.

If our pond fish don’t eat the eggs (as fish are inclined to do), the tiny larvae (tadpoles) will be using their scraping mouth parts to eat the algae at the bottom of the pond. They will have to keep hiding from the fish until they complete their metamorphosis and can climb out of the pond.