The Winogradsky panel is developing much more quickly than I had expected. Differences are noticeable from day to day.
The modified mud layer now has more black spots and there are now some bright green spots, probably green sulfur bacteria. GSB are more tolerant of high H2S concentrations than the purple sulfur bacteria, so are growing well in the areas where the black spots tell us there is H2S. Note the gas bubbles at the bottom center of the image. The squiggly lines are actually paths left behind by the movement of small, red larvae of midge flies, called blood worms. They made their way up to the top, and are now all apparently dead. (And will be food for some bacteria).