Week Three Observations (Thursday, Nov 4)

Changes: There was not a dramatic change in my microaquarium compared to last week. Just like every week, water had evaporated. I observed a slight increase in the number of organisms in addition to an increase of dead matter. Most of the dead debris was on the bottom of the tank, but there were also parts of my water moss and bladderwort that were decaying (near the surface of the tank).

Organisms: The most obvious change concerning life in my tank was an increase in nematodes, seed shrimp, and centropyxis.

Nematodes: I found this one on the bottom of the tank. It was very busy digesting whatever it could vacuum into its mouth (Patterson, 1996). I found several more nematodes squiggling around in my water moss, bladderwort, and soil.

Paramecium: This is a Paramecium Bursaria (Egmond W V, 1998). I found it near the surface of the tank. I spotted at least three more around the plant matter and near the soil. It swam rather fast, while it swam the Zoochlorella algae inside circulated rapidly (Egmond W V,1998). The paramecium has a symbiotic relationship with the algae.

Centropyxis: These organisms appeared in huge clumps all around the water moss and in the soil. They are unicellular and stationary (Patterson, 1996). Centropyxis is an amoeba that usually has spines on the outside. These are young and therefore have not developed their spines yet.

Ostracods: Last week I only found one seed shrimp. This week, however, I saw two or three on the bottom.

Cyanobacteria: The number of cyanobacteria remained unchanged from last week. Once again, I found them everywhere.

Plants: Both my plants showed signs of decay. The water moss had chunks worn away from their previously pointed leaves and the coloration was turning from bright green to brown on the tips.


Diatoms: I observed a slight decline in the number of diatoms. A few on the bottom could have been dead, but it was hard to tell since my diatoms are normally stationary.


Rotifers: These guys were all over everything. I spotted at least nine, all of whom were feeding on either bacteria, plant material, or on material on the soil layer.


Flatworms: I found one huge flatworm on the bottom of my tank. It was obviously the same one from last week.




Citations:

Patterson D. 1996. Free Living Freshwater Protozoa. A Colour Guide. Drawings by Stuart Hedley. 73 Corringham Rd, London NW11 7DL: Manson Publishing. 28 p. Figure 18.

Patterson D. 1996. Free Living Freshwater Protozoa. A Colour Guide. Drawings by Stuart Hedley. 73 Corringham Rd, London NW11 7DL: Manson Publishing. 95 p. Figure 184.

Egmond W V. 1998 [cited 2010 Nov 7].Green Algae. [Internet]. Microscopy-UK. Available from:http://www.microscopy-uk.org.uk/mag/indexmag.html?http://www.microscopy-uk.org.uk/mag/wimsmall/smal1.html