Observation 11-9-10

Today was the final day for observations of our MicroAquariums. The organisms in mine seem to have slowed down quite a bit. There were very few "larger" organisms left to observe. All of the ostracods, or seed shrimp, appear to be dead. The water mite that I observed earlier was nowhere to be found, nor was the large Annelid. I did see a few smaller Annelid worms that I hadn't noticed previously. There were also fewer rotifers, although the ones that were present were much larger than in recent weeks. Some of the smaller organisms increased in number, however. The number of parameciums appeared to have tripled, as did the population of Fragillaria. I did observe a phenomenon that seemed very strange: there was a large group of Navicula that were arranged in a single-file line. This line contained at least a hundred of the organisms. I asked Dr. McFarland about this, although he wasn't sure of the cause.

Observation: 2 November 2010

Today during my observation I saw a very active ecosystem. There are more organisms than last time I did an observation, and the organisms that are there are larger as well. The rotifers in particular have gotten quite fat. There is a lot more filamentous algae, and it is mostly concentrated towards the surface of the water. I also noticed seed shrimp for the first time, and in fact there are at least a half dozen of them. Here is a video I took of one feeding:

Smith D G. 2001. Pennak's freshwater invertebrates of the United States. New York, NY: John Wiley & Sons, Inc. 648 p.

While I was looking for one of these seed shrimp with the camera microscope, I also noticed a very strange organism. He had very obvious hair and legs and was not transparent like most of the other inhabitants. I discovered that this was a water mite, which is a member of Hydrachnidae:

Rainis KJ, Russell BJ. 1996. Guide to microlife. Danbury, CT: Franklin Watts. 288 p.

I also found more annelid worms, but was unable to capture the new ones in a picture or video.

Observation: October 26

I observed my MicroAquarium again today. It looked like things had settled down since I moved all of material into a new slide. Dr. McFarland had added a food pellet to the aquariums before the weekend, and I noticed a lot more movement. There were many small bacteria swimming about crazily, and I found some larger organisms as well, such as an annelid named Aeolosoma sp. This worm spent most of its time buried in the sediment at the bottom of the tank, and when it emerged it would flare a group of hair-like projections outward.

In: Thorp J H, Covich A P, editors. Ecology and classification of North American freshwater invertebrates. San Diego (CA): Academic Press, Inc; 1991. 1056 p.
Figure 12.7

The food pellet that was added has the following information:

"Atison's Betta Food" made by Ocean Nutrition, Aqua Pet Americas, 3528 West 500 South, Salt Lake City, UT 84104. Ingredients: Fish meal, wheat flower, soy meal, krill meal, minerals, vitamins and preservatives. Analysis: Crude Protein 36%; Crude fat 4.5%; Crude Fiber 3.5%; Moisture 8% and Ash 15%.

I also found an Anisonema sp., which appeared to be probing other objects in the tank with a long flagella. It whipped around crazily before settling on one unidentified object.

Patterson, D J. Free-living freshwater protozoa: a colour guide. Washington, DC: ASM Press, 1996. 54.

Figure 77