
Wednesday, November 17, 2010
Week Five
When I picked up my Microaquarium last week I immediately noticed how it lacked water, and I was interested if this had any effect on the organisms. I also wondered if this has exaggerated my thoughts of how much of a population increase there really has been, since the organisms may just be running out of room. Yet, despite my second thoughts, when I looked into the microscope there is no denying the fact that the organisms, especially the seed shrimp, are reproducing at an alarming rate. As each week passes the numbers of ostracods looks like it doubles. The most diverse location in my aquarium now looks to be the soil resting at the bottom, instead of both plants as it was in recent weeks. I hypothesize that the amount of organisms in the soil can be attributed to the large amount of dead matter and waste that make up the sediment. One type of rotifer I identified was the Philodina rotifer, and I recognized this fairly quickly due to the two, wheel-like, spinning trochal disks this species uses for feeding. I watched this organism closely for a few minutes, and noticed how these ciliated appendages can be retracted and released by the rotifer. Despite my captivation with this particular organism, I wanted to further examine the soil and get numbers on seed shrimp inhabiting this area. I followed the soil with my microscope on 400x for the whole length of it and counted thirty seed shrimp, and I also noticed with surprise that the unidentified larvae from previous weeks was feeding deep in a layer of soil. The pellet-like diatoms have not grown at all from their tiny size but they still seem to be numbered in the thousands, and I am interested if they are at the beginning or end of their life cycle.
Sunday, November 7, 2010
Week Four Observation
The contents of my Microaquarium closely resemble the state they were in last week in regards to variety of organisms and the shape of the elements within. There is still an overall feeling of messiness compared to the first two weeks and it seems as though the ostracods are thriving in this new environment. The amount of seed shrimp is somewhat overwhelming, and even with the naked eye one can observe their numbers inside my aquarium. Another organism that must be reproducing at an alarming rate is the diatom. The small yellow pellets I described last week have surprisingly grown in number and in size, and the diversity of diatom species is surprising as well. Next week I'll name particular species but there seem to be all varieties: long, green species, small, yellowish-brown species, and small, slender species that seem to even be mobile. One organism that I observed within the Utricularia gibba are flatworms, I only saw two of them and I looked for more but I could not find any others. They were gliding slowly in and around the leaves of the plant. I also saw an amoeba, and it was so small that I could hardly notice it, and I strained to find more but could not. Next week I will try to find numbers on these organisms as well but right now they seem rare. It also appears that the insect larvae from my first couple of observations may be dead. It was always relatively easy to find and I failed to find it this time. The numbers of rotifers look as though they are decreasing, because wherever I was looking last week there were five to ten in my field of view, this time there were not nearly that amount.
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