Week 2 Observations

Organisms Present

-Cyclops

-Daphnia

-Closterium

-Chaetogaster

-Unknown Nematode (moving to fast to identify)

-Diatoms

-Freshwater shrimp

-Pleurotaenium

     This week on October 23, I made my second observation of the microaquarium. This week there seems to be more movement and I have spotted more of the transparent Cyclops swimming around. I saw a total of 7 Cyclops during this observation which is more than I saw previously. The Cyclops are a grey color and are in various life stages and move around quickly. The Cyclops is a multicellular bacteria that does not have a green color and therefore does not contain chlorophyll. this organism tends to stay around the sand/soil at the bottom of the aquarium or sightly above, swimming near the plant.

     This week, the most interesting thing I observed was an annelid, the Chaetogaster. This organism is multicellular, segmented, and looks like a worm. This organism is identified by its mouth which is located on its bottom side and a hook on the end. I was able to observe this organism move around and consume another organism as well as watch it release waste. This organism was slow moving and seemed to pull itself around with its mouth. This organism was mostly transparent and and did not contain chlorophyll. This organism tended to stay around the sand, soil, and roots of the plants within the aquarium.

     Another organism I found this week is the Closterium. This organism is a desmid, meaning it is a type of green algae. I spotted about 5 of these organisms while making observations. The Closterium is characterized by a thick middle joint and bright green colors, indicating chlorophyll. This organism contains two chloroplasts and has general crescent shape to it. Closterium seemed to be stationary as I was viewing it and tended to float around in open water. In addition to the previous desmid, I was able to view a Pleurotaenium, another unicellular chlorophyll containing green algae. These organism also seemed to be stationary and were found in open water. Like other desmids, this organism has a thick middle joint.

     This week I was also able to observe a few organisms that I was not able to fully identify. These organisms included a type of diatom was stationary, or floating around in open water with no apparent movement mechanism. I was able to view 6 diatoms that were grey in color. Another organism I was unable to identify was a very fast moving nematode. I was only able to view the nematode for an instant on the computer screen before it was gone but was reassured by Dr. McFarland that it was in fact a nematode. The nematode jerked violently and looked like a dark grey worm.