Final Observation

My last observation in the lab was great.  The activity in the micro-aquarium increased every week from the beginning, which made this very fun for me.  I never saw my water bears again, but I did observe other new species I had seen yet.  One of which was the Bacillaria paradoxa, a fascinating organism also known as the carpenter's ruler.  I actually had an audience with me as we watched this species sling itself around the aquarium.  This species is segmented and each cell grows into another until it has great length.  It moves like a slinky and can go in opposite directions.

Figure 1. Bacillaria paradoxa with a Litonotus at the bottom.

I identified the Bacillaria in The Fresh Water Algae book (Prescott, p. 241).  I noticed a few Litonotuses; these were very cool organisms to watch fly around the tank, and I was lucky enough to snap a photo as one swam by the carpenter's ruler.  All members are flattened predatory or scavenging ciliates (Patterson, p. 133).  The next species, Urocentrum, behaves like a spinning top (Patterson, p. 167).  This species frequently feeds on suspended bacteria as the cell spins around.  It was not a very hard species to obtain a picture of because it moved very slowly.

Figure 2. Urocentrum spinning through the aquarium.

Figure 3. Stenosomum in the grass.

In Figure 3, a Stenostomum tenuicuada, predatory flatworm, slowly moved around my aquarium (Pennak, p. 144). Finally, my most famous species was the Euplotes (Patterson, p. 124).  These guys were all over the place; they seemed to multiply throughout the weeks.  I noticed in these last two weeks that the euplotes were heavily at the bottom of the micro-aquarium near the soil.  They were scurrying throughout the entire slide though.  I'm sure they served as a great abundance of food for all the predators in my water as I witnessed a water bear consume one last observation.

Figure 4. The most common organism in my observations, the Euplotes.

Overall, this experiment served as great insight into the microbiology of fresh water sources around Eastern Tennessee. I'm very satisfied I chose a natural river outside of the Knoxville area because I don't think I would have been able to observe these predatory organisms.

Observation 3

Last week I noticed an incredible amount of activity in the aquarium.  Some peoples' micro-aquariums are losing activity as the weeks go on, but that is not the case for my project.  I'm seeing more organisms and more movement throughout the slide.  I used a microscope for searching throughout my micro-aquarium.  I noticed the midge again, which has grown bigger and is full of green food from the plants it consumes constantly.  I also discovered a flatworm (Stenostomum Tenuicuada) inching around the slide.  It moved very slowly but would react quickly if it ran into another organism (Ward & Whipple p. 336).

Another organism that took awhile to identify was the stylonychia, that flipped around in the same place for the entire time I observed it (Patterson, p. 123).  It remained in the one area, so I got to see it move for awhile (wish I had recorded a video).  The euplotes were in full force again; they are by far the most abundant species in my micro-aquarium.  I saw many of them hanging around the soil section of my slide. I did get a great view from the side of the ciliate which illustrates how the ventral cirri that characterizes the hypotrichs are used for movement over a substrate.  Thr adoral zone of the membranelle draws a current of water under the cell towards the cytosome; suspended particles may then be removed by the ciliate from the current (Patterson, p. 124).
One of the coolest moments of this entire experiment has been my observation of two water bears (tardigrada) (Pennak, p. 257).  Dr. McFarland explained that he had only seen a water bear once this year out of everyone's micro-aquariums!  I followed one around the water as it consumed every organism in its path.  I witnessed a euplotes in the wrong place at the wrong time, which was very cool.  The water bear looks like a caterpillar on a war path.  Finally, Dr. McFarland pointed out an arcella stationary in the water (Patterson, p. 91).  I didn't even know it was an organism, but it is a circular amoebae with a smooth exterior and a hole in the center.  I will post as many pictures as I can this next week, hopefully a few of the water bears.

Observation 2

Last Wednesday, I returned to the lab and had a very successful session identifying different organisms.  I started off on a microscope, where I scanned through the entire micro-aquarium back and forth several times.  I wanted to see what type of activity was happening throughout the slide.  I noticed many more organisms eating the plant stems but also floating around in the open water.  The light from the microscope had no effect on the them, as they did not scurry off like they did in earlier observations.  Most of the organisms were staying in the middle of the aquarium.  One of such creatures was the midge, which I wasn't able to get a picture.  I also discovered several Euclanis Rotifera floating around the open water (Pennak, p. 171).
I then moved to the computer and recorded two videos of activity within my micro-aquarium. The first shows an anisonema stationary (Patterson, p. 54).

This second video exposes a coleps in the micro-aquarium, while a euplotes flies by (p. 163).  Dr. McFarland assisted me in identifying these two organisms, research which I discovered in the Fresh-water Invertebrates of the United States and Free-living Freshwater Protozoa. I will gather more pictures this week, hopefully of the midge because I had a great time observing it.