The tadpoles are in various stages of development, even within an individual spawn clump. Some are still in their early phase, unmoving. Others are wriggling and agitating regularly. Some have clearly-defined frilly gills. And, today after work, I noticed that some tadpoles have broken free of their protective jelly spheres and are on the move within the clump.
The light was fading when I managed to get down to the pond to look, so, to let you see the movement, I put my hand in the pond under the clump. Now the tadpoles were distinct against my skin. Here’s what I saw.
The surface of the water around the spawn clumps is dotted with air bubbles which make a dramatic, artistic image.
According to Sussex Wildlife Trust, the bubbles may be oxygen, released as the spawn begins to break down and used as the first food source for the tadpoles.
FROG BLOG 