Final MicroAquarium Observation

For my last observation, I noticed that a lot of water had evaporated from my MicroAquarium and that both plants present in my aquarium looked very unhealthy due to feeding by the aquatic organisms.  The Amblestegium sp. moss appeared to be the preferred food source among the microorganisms because it looked like it was fed upon the most. With the noticeable depletion of plant material, came the apparent slowing down of life in my MicroAquarium; organisms seemed to move slower, and their relative abundance seemed to have decreased slightly.  I still saw a few Tachysoma sp., Euplotes sp., Actinosphaerium sp., Vorticella sp., and Euchlanis sp.  The midge that first appeared during my previous observation was still alive and active during my final observation as well.  Most of the activity that I noticed during this observation occurred near the soil surface where I saw a lot of diatoms, rotifers, and Euplotes sp.

Around the middle of my MicroAquarium, it looked as though the diatoms I saw during my last observation had taken on a new shape.  I saw a lot of bright green, linear, spiky, glass-like organisms arranged in a clumped fashion (Figure 1).  Through some research Dr. McFarland and I concluded that this living creature was probably an Ankistrodesmus sp. (Smith 2001).  This green algae is usually found in freshwater lakes and ponds and it is usually arranged in parallel bundles, with some bundles which rotate, giving the colony a spiked appearance (Algaebase 2011).  More information on the Ankistrodesmus sp. can be found at http://www.algaebase.org/search/genus/detail/?genus_id=44102&-session=abv4:D860C4D31b20707C6ARno2C5C147.

I thought I had discovered a new species in my MicroAquarium when I saw a beetle-like organism crawing up one of the plants.  It looked as though it had legs.  When I asked Dr. McFarland about the organism, he informed me that it was a Euplotes sp., which I had already identified in my MicroAquarium two weeks ago (Figure 2).  Upon further research, I learned that the Euplotes sp. have large cilia that is tufted together to form cirri, which help it to "walk" along objects (Microbus 2010).  When I first saw these creatures, they were gliding along the water in my microaquarium, rather than "walking" on objects, so when I saw them "crawling" up the plant steams, I thought I was witnessing a different type of organism.  More pictures of these fascinating creatures can be found at http://www.microscope-microscope.org/applications/pond-critters/protozoans/ciliphora/euplotes.htm.

I also saw more Tachysoma sp. in my MicroAquarium, and they seemed to be the most abundant during this observation session.  I was able to take a better picture of this organism as well (Figure 3).

While closely inspecting my aquarium, I saw few organisms that looked like clear blobs of different shapes with little spheres moving inside of them.  I was able to identify them as Amoeba sp. (Figures 4 and 5).  Amoebas are single-celled organisms that can take in food by surrounding and engulfing it (FCPS 2011).  These bits of food and other particles are probably what I saw floating around in the amoeba's cytoplasm.  Interesting facts on amoebas can be found at http://www.fcps.edu/islandcreekes/ecology/amoeba.htm.

Lastly, I saw a beautiful Gomphonema sp. (Figure 6).  It looked like two golden flowers which were connected by their stalks.  It also had a shape similar to the Vorticella sp.  According to Freshwater Algae: Their Microscopic World Explored, the Gomphnema sp. have a stalk, which can be branched to form a tree-like shape and that they spend most of their lives attached to a substrate.

Overall, my last MicroAquarium observation was very productive and enlightening.  I enjoyed doing my observations over the past 5 weeks, and I particularly liked learning about each of the individual microorganisms.  Each creature had its own unique features, which always sparked my interest.  Hopefully, the general public will look upon my blog as an interesting account of the secret life of microorganisms.



Figure 1 (corresponds to Figure 180 on page 265 of Fresh-Water Algae of the United States, second edition)




Figure 2 (corresponds to Figure 260 on page 124 of Free-Living Freshwater Protozoa: A Colour Guide)




Figure 3 (corresponds to Figure 265 on page 125 of Free-Living Freshwater Protozoa: A Colour Guide)




Figure 4 (corresponds to Figure 195 on page 98 of Free-Living Freshwater Protozoa: A Colour Guide)




Figure 5 (corresponds to Figure 192 on page 98 of Free-Living Freshwater Protozoa: A Colour Guide)




Figure 6 (corresponds to Figure 231 on page 129 of Freshwater Algae: Their Microscopic World Explored)



Changes to my MicroAquarium on 11/3/11

While looking at my MicroAquarium this week, I found the ecosystem appearing slightly different.  The plants did not look as healthy.  Upon further inspection, I saw that the Euchlanis sp. and Euplotes sp. populations has increased dramatically.  Around every plant stem and bladder, I could see these organisms feeding on the organic material and quickly moving from one area to the next.  These aquatic creatures seemed to favor the Amblestegium sp. moss more than the Utricularia gibba L. flowering plant.  The Amblestegium sp. moss had grown spike-like filaments that emitted from its bladders, while the Utricularia gibba L. had grown brown, hair-like filaments from its stalk.  I saw fewer Vorticella sp. this week, which led me to believe that the Euplotes sp. and Euchlanis sp. were outcompeting them. I observed a slight increase in the nematode population, but exact numbers present in my MicroAquarium were only around 3 to 5 individuals.

To my surprise, I encountered an extremely large, red creature while looking under the microscope.  I could also see this organism with my naked eye. Dr. McFarland identified this creature as a midge larvae, Chironomous sp. (Figure 1).  Using a text titled Fresh-Water Biology, we saw that this midge resembled Image number 1384 on page 915.  It had created channels in the Amblestegium sp. moss by consuming the moss's inner vascular tissue. It was so large, that when is wiggled around, it would move the entire plant.  Information gathered from www.mosquitoes.org/Midge.html indicated that midge larvae are often called blood worms and are commonly found in muddy river bottoms of large rivers, which corresponds to my water sample because it came from the French Broad River.  This midge larvae moved faster than a worm, and it also used a frontal appendage to pull itself along.

Dr. McFarland and I also identified a new inhabitant of my MicroAquarium, a Tachysoma sp. (Figure 2).  According to Dr. McFarland, this particular Tachysoma sp. was unusually large because it was about to divide.  A special feature of this genus is the well-developed, immobile dorsal bristles (Patterson 1996).

The next new organisms that I encountered were the Navicula sp., the diatoms (Figure 3).  They looked like yellow pellets that hovered over the soil surface.  Diatoms are often found in great numbers in small areas, which relates to their abundant populations in my MicroAquairum (Raven and others 2005).  Diatoms are also a major food source for many aquatic animals (Raven and others 2005).

I also encountered a puzzling mystery while viewing my MicroAquarium.  I noticed a yellow mass that was suspended above the soil surface and looked similar to the diatoms.  Upon closer observation, I could see that this mass was made up of individual organisms that were yellow with large, blue centers (Figure 4). I asked Dr. McFarland if he knew what these organisms were, and he said that he was not sure.  After doing some research, we concluded that the closest genus we could compare this organism to were the "Plasmodiums."  In the future, we will hopefully be able to more accurately identify this organism, but for now, they will remain a mystery.



Figure 1 (Corresponds to Figure 1384 on pg. 915 in Fresh-Water Biology)




Figure 2 (Corresponds to Figure 265 on pg. 125 of Free-Living Freshwater Protozoa: A Colour Guide)




Figure 3 (Corresponds to Figure 237 on pg. 130 of Freshwater Algae: Their Microscopic World Explored)



Figure 4 (no citation or source because unsure of this organism's identifcation)