Observations Week 4

I observed my MicroAquarium for the last time November 11.

Once again, the water level was low. I added a few drops of distilled water to account for evaporation.

The two food pellets added in previous weeks were completely dissolved. Whereas last week the aquarium was swarming with microorganisms, this week movement was scarce.

There was almost no movement in open waters, and I noted the most movement around the plant samples: namely Aeolosoma.
Last week there were dozens of Paramecium, however, this week there were very few. Additionally the numbers of cyclops, flatworms, and other motile microorganisms were greatly reduced.

There was a thick layer of dead organic matter lying on the bottom of the tank in the substrate, primarily consisting of dead Paramecium and Aeolosoma.

Because of the lack of movement, I noticed many more non-motile organisms.

New organisms I observed this week included:

-Coleochaete irregularis, a small green alga found in open water. It exhibits radial and lateral branching from a central filament.

-Several diatomatic organisms. Especially abundant were Tabellaria sp., a colonial alga of the phyla Diatom.

-Some dead green alga, notably Closterium sp. : a chlorophyllic, crescent shaped organism found in open waters.

An organism observed in previous weeks, but more closely noted this week are the Vorticella sp., a small tulip-shaped protist attached to plant samples with prominent cilia.