Where Have All the Actinosphaerium Gone?

The creature in the photo to the right has been identified as an Actinosphaerium. This picture was taken on 10-31-07 when it was fairly simple to find one of these in the aquarium. Now, about one week later they are no where to be found. In general life seems to be slowing down in that there are less organisms to be found and what is still alive and moving is doing so at a slower pace.

Note: That is my name in the picture, not the organisms name.