The observations of the week were characterized as a reduction in motile activity and an increase in the amount of photosynthetic bacteria present in the microaquarium.
For example, some of my largest finds such as the annelids and nematodes were much harder to find. I could only find one annelid, but this one was shorter than my findings in previous weeks. I also found a single nematode this week. it was much easier to observe. Rather than constantly springing around elastically like the nematode observed in week one, this one was slithering slowly when I spotted it. This allowed me to zoom in and identify the mouth and the anus. After slowly moving about, it finally began the elastic movements, but with less zest and celerity.
The seed shrimp below was less visible this week-my total count while in the lab was two. Both were near plant A. The most notable observation was that it tended to be much slower in its movements. The first Seed Shrimp I found was searching for food, and, like the annelid I found in a previous week, would move exhibit a recoil reaction to bumping into strands of plant A. The second one I mistakenly thought at first to be dead. It was resting near the sand of plant A, simply not moving. When I focused the lighting and the lens it then moved upwards. The lack of visible color also led me to believe it was dead.
Mikel, G. Seed shrimp illustrated. Gina Mikel Illustration Photography. 2009.
Available from: http://www.scientificillustrator.com/illustration/fish/seed-shrimp.html The cladoceran, as pictured below, was found in less quantity as well, and had been one of the most prominent organisms in the microaquarium. The movements of the cladocerans were also a bit slower, with movements tending to occur on near the tips of the plant strands. In the bottom right corner of the image is what may have been a notosolenus or a that was to the left of plant A. This shows that the cladocerans movements were not only confined to either plant, but were rather very mobile creatures that found food near the center of the microaquarium as well.
Rains, K., Bruce, J. 1996 Guide to microlife. Watts Danbury, CT: Children's Press 212-218p
In general, stationary often green to yellowish green organisms were more present in the background of the aquarium. My summary of the quantity of these organisms is probably not just considering how many there were. As conferred with Dr. McFarland, however, the visible presence of more of these organisms reflects the growth of cyanobacteria in the microaquarium.
The notosolenus were again present this week, just as last week. Their movement still seemed to be energized but stationary. However, their remaining presence follows with the evidence of there being less motile organisms present.
Patterson, D., Hedley, S. 1992 Free-living freshwater protozoa: a color guide. Washington, D.C.:Manson Publishing 54p.
The flagilaria were a pretty find. The bluish tint in the background of this photo can be attributed not to the microscope or a new presence in the water, but merely a camera setting. However, the benefit was that the contrast in colors accentuates the shape and coloration of the flagilaria. This is a common photosynthetic algae that is characterized by its shape and the presence of chlorophyll. This image depicts the tendency of flagilarian chlorophyll to gather near the center of the organism. There were two other flagilaria in my microaquarium residing more in between the two plants and typically lower. There were some transparent flagilaria near the bottom. These were most likely dead and no longer producing energy as evidenced by the lack of green chlorophyll for photosynthesis.
Tiffany, L., Britton, M. 1952 The algae of illinois. Chicago, IL: The University of Chicago Press 231-235p.
This was the clearest photo of a paramecium that I found. It is single celled protozoan. Paramecium bursaria are supposed to have cilia, and although this one surely did, they are so small, in contrast to the more visible flagella of other organisms, that they are not very visible in this image. What is captured is the symbiotic relationship occurring in the paramecium bursaria's cytoplasm. The relationship is that the zoochlorella, the spherical green algae visible throughout the cytoplasm provide food for the paramecium while the paramecium provide protection and movement. However, this image was easy to obtain because this paramecium bursaria's movement was near zero.
Also, still visible from the prior week were smaill traces of Gloeocapsa Calcera. This is the prokaryotic autotroph reported last week. This image provides a faint view of the gelatinous sheath that it secretes around recently divided cells. Thus, this is a also a snapshot of an early stage in the biological life cycle of the gloeocapsa.
Prescott, G. 1951 Algae of the western great lakes area. Dubuque, IA: W.M.C. Brown Company Publishers 451p.
To my sincere dismay I could only find but one more amoeba. Hopefully this video provides an adequate visual aid for the gloppy movements characteristic of amoebas. This one was found near the higher part of the tank. Also, visible are the litonotus samples floating around! Enjoy!
Patterson, D., Hedley, S. 1992 Free-living freshwater protozoan: colour guide. Washington D.C.: Manson Publishing
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