Week Four

For my last observation I noticed that the plants were still in the same state: a few green branches and some visible molds and I needed to add a little water. Under the microscope there I could see the continued increase in diatoms and cyanobacteria and a larger number of epilaxis and euchlanis. I was unable to find any vorticella which had been prevalent last week. I saw a few amoebas, including one that had engulfed a diatom but could not find the protazoa I had seen last week (and photographed but didn't manage to photoshop to include here). I saw two other kinds of horned rotifers but was unable to identify them. I saw and identified a cyclidium (Patterson) and an anisonema (Patterson, Fig 78)*.

I did not have time to identify with a book the above amoeba but chose to include the picture anyway. This was one of several I found in my aquarium last Thursday.




Here we have a cylcidium surrounded by diatoms. Under the microscope I could observe the large central vacuole expand and contract.

In general I observed that the larger organisms I observed at the beginning disappeared and the smaller organisms, particularly the diatoms and cyanobacteria increased. The protozoa did not increase at a great rate but did increase over the weeks I observed.






*Patterson, D. J. Free Living Fresh Water Protozoa. Washington, DC: Manson, 2009.