*water was added prior to these observations equal to one third the total volume of the aquarium.

I first observed the area outside of the plant matter and mud in the bottom. So basically the empty space between the plants and mud. The first organism i saw was an oval shaped transparent multicellular creature. It was propelled by a large single flagella. It randomly swam around taking small bites of things. Many of these were observed. I have not identified this creature yet.
The second organism observed was a bean shaped shelled organism. This one was frantically eating the all of the green parts of plant b. This creature could be either a cypria or cypridopsis (Rainis & Russel). There were many of these organisms present.
A third organism was observed that was very similar to the second except for this one was considerably more transparent than the other. Both seemed to be shelled. This creature was found feeding in plant b as well as in the bottom in the mud.
Last thing observed was that there was no visable movement around plant a.