Final Observation

This week was the final observation of my MircoAquarium. The first thing I noticed was that about two-thirds of the water in my MicroAquarium had evaporated. This made it a little more difficult to find the surviving organisms living in the water. There were still some present, although, I viewed numerous carcasses floating about.

The most exciting thing to note was that I discovered a new organism. I saw several of them skimming the MicroAquarium. I would say that these organisms had been developing over time and were just recently able to be seen. They appeared to be eating the decaying debris and carnage of the MicroAquarium "floor." These organisms were clear in color and had a split tail. Their bodies were lined with cilia. I saw about 3 of these organisms: gastrotriches. After doing some research, I found out that gastrotriches eat bacteria, algae, small protozoan, and organic detritus (Pennak, 1989). While watching, I saw a gastrotrich eat a diatom.



Another find were the Lecane rotifers. There were a handful of them still living, as well as a couple that were deceased. The rotifers flowed around in the water with ease. They had a circular clear body with a single tale at their posterior end.



The algae in the MicroAquarium had grown substantally. There was lots of algae and cyanobacteria present in the MicroAquarium. One particular patch of cyanobacteria was from the Merismopedia genus (Tiffany and Button, 1952). It looked like a checkboard of dark green squares.



There were also a good amount of tiny clear spheres darting around in the water. They were present in the plant material of Plant B. They seemed to be "throbbing" and appeared to move by means of flagella. I was unable to identify these organisms.

I saw a Euglena, which Dr. McFarland and I identified by keying it out in The Algae of Illinois. It was Euglena spirogyra. I took a short video of this particular organism as well as snapped a couple of photos. It was really neat to see the details that made up the structures of this organism. Under magnification, you could see the ridges within it. There was a flagella at the anterior end and a single tail at the posterior end of the Euglena spirogyra.



Diatoms were also present; they were scattered throughout the MicroAquarium. These organisms are not motile. Another organism I spied was in the Aspidisca genus. These are some of the smallest hypotrich ciliates (Patterson, 1996). They are clear in color, spherical in shape, and have cilia on both ends. There is a "hook" structure on one end. The final organism I identified was a Tachysoma--a hypotrich with dorsal bristles, brownish color, and immobile in nature (Patterson, 1996).



In conclusion, I enjoyed viewing my MicroAquarium. It gave me the opportunity to explore the world of freshwater invertebrates. I was enlightened as to how a small amount of water could contain such a diverse ecosystem. Towards the end, I saw a decline in the activity and presense of living organisms in my MicroAquarium. I feel that if this project had continued on, the ultimate decline of the entire ecosystem would have been in the near future. I believe this would have been due to a lack of food, inadequate sunlight, and loss of water in the MicroAquarium.