Week 5: Last Week

This week there were quite a few obvious differences other than those observed using the microscope. The water level was noticeably lower and the aquatic plants were faded in color and starting to break up like pre-decomp sorta. Similarly the soil and silt at the bottom was gray in color and grainy, seeming like it may be nutrient poor or depleted. Using the microscope i noticed a vast increase in spirogyra, both in number and in size. Also there was a significant increase in desmatodes and colonial green alga. The increase in these photosynthetic microorganisms I believe is due to the more abundant photons and CO2 as the plants die and are no longer competing for the same resources. There were hardly any rotifers, especially considering they were everywhere the first 4 weeks. They seem to have been beat out by the paramecium, as they were abundant in every field of view. The nematodes were few in number yet those surviving were far larger than those observed in weeks past. No new species of microorganisms were discovered in this final week.

Week 4: New Observations

This week in lab, while observing in my MicroAquarium, I found a lot of the same stuff that i had before. Lots of rotifers everywhere, spirogyra, and a couple big snails. I found more diatoms, especially down by the silt at the bottom. I also finally found a Cyclops (a Copepd). There seemed to be a larger number and variety of cyanobacteria, or blue-green alga such as Cosmarium, Oedogonium, and some types of Anabaena. Most of these were colonial or fillamentous. They seem to have no preference in where they exist. Likewise they have sprung up in the past week greatly throughout the MicroAquarium. Also in the MicroAquarium I'm beginning to notice a lot more dead, and emptied protist and single celled organisms. Lots of remaining seed shrimp cytoskeletons, and lots of clear cells that were green and vibrant last week. Unsure whether this is due to lack of oxygen or they no longer were able to sustain in the given habitat afforded to them. Either way it has become more prodominent, especially in the seed shrimp it seems.



Canter-Lund, H., Lund, J. Freshwater Algae: Their Microscopic World Explored. Bristol: Balogh Scientific Books; 1995


Rainis, K., Russel, B. Guide to Microlife. Houston: Children's Press(CT); 1996