10/29

During the first fifteen minutes of observing my micro-aquarium, I expected the organisms to be very inactive; but after searching and constantly refocusing the microscope, I found the contents of my aquarium more active than they were in my first observation.

The very first organism I found was a type of rotifer. It took some time for me to identify it due to my ignorance of microscopic aquatic organisms, and after studying some of the identification posters around the lab, I guessed it was a type of freshwater Daphnia. A picture of the actual rotifer (right) shows its similarities to Daphnia, which can be seen by clicking on the link: http://cfb.unh.edu/cfbkey/html/Organisms/CCladocera/FDaphnidae/GDaphnia/Daphnia_rosea/Daphnia_rosea1large.jpg

My majority of time in lab was spent observing this type of rotifer, whose quantity was too numerous to count. Though I'm unkowledgeable of rotifers, I guess their appendage is used either for consumption or to become immobilized. I assume its use is for stationary purposes because for nearly ten minutes I watched one rotifer whose appendage appeared to be stuck inside another organism. It struggled until it became tired and would shortly rest before making another attempt. Once free, it quickly swam off to another part of the aquarium.

The most interesting part of my observation was found in the soil. I took a long time for me to find the right adjustment and lighting on the microscope, but once I did, I saw some very active nematodes (small, worm-like creatures of the kingdom Animalia), and what I believe was a flatworm. The pictures of the nematodes below were taken when they had immerged from the soil.

At one point, a nematode and the flatworm were swimming towards one another, and collided. As soon as they touched, the nematode cowered and quickly swam off in the opposite direction. Sadly I could not get a clear photo of the flatworm, but the image below is a decent depiction of what I observed:
http://www.brightonps.sa.edu.au/edweb/sue.macmillan/file/Flatworm

10/14

For the creation of the MicroAquarium, 12 random water samples were provided. I extracted water and soil from sample #7 and placed a portion of two provided plants (plant A and plant B) inside the aquarium.
When studying the contents of the aquarium, I focused on the observation of two organisms: A rotifer and an epistylis. Information for each organism was found in the provided links below.
Rotifer: multicellular organism recongnized in the animalia family. They have complete digestive tracts (including mouth parts and anuses) and have specialized organ systems. Certain species can procreate asexually. Rotifers are archaic organisms; some of their fossils dating back to the tertiary period of the Cenozoic Era (33.7-54.8 million years ago).

www.ucmp.berkeley.edu/phyla/rotifera/rotifera.html

Epistylis: a type of protozoan whose structure consists of a stalk-like body and a bulb-like head which can be seen when "colonies" cluster on the outer layer of certain crustaceans. Epistylis generally feed on bacteria and particles in the water. It is thought that "their abundance is directly proportional to the degree of organic pollution in the water." I thought these were especially interesting. They appeared to stem out of plant and had peculiar body movements. They would coil (almost similar to a slinky) and then their stalk would quickly straighten. It seemed that during this stage, they were feeding on smaller particles that floated into their open mouthparts.

www.fish.wa.gov.au/docs/pub/FHEpistylisTemnocephia/index.php?0408

An image of an Epistylis can be seen by clicking on the following link:
http://school.uaschools.org/tremont/MediaCenter/AskRob/robgraphics/epistylis2.jpg