Week #5

I observed dozens of the Dileptus I first saw last week. They outnumber pretty much every other organism in my MicroAquarium at this point, even the rotifers, which up until now had been the most prevalent residents. I saw a few Vorticella and Halteria, but their numbers appeared to have decreased. The diversity of the environment seems to have diminished since last week. Also, for the first time this week, I observed an organism large enough to be seen with the naked eye. Under the microscope, I viewed a long, segmented creature, with multiple cilia and a long proboscis. It moved very quickly, and it was difficult to get a good look at the organism at first, which led me to wonder if maybe this organism was sensitive to light. Pennak's Freshwater Invertebrates of the United States (Douglas Grant Smith) identified this organism as the Annelid Stylaria.

Week 4

I definitely noticed an increase in diversity this week. Still noticeably present were the rotifers Lecane. Additionally, I noticed a large number of green algae, identified as Phacus in How to Know Freshwater Algae by G. W. Prescott. I also observed two of the Difflugia I identified earlier in the semester, illustrated in a 40x image below.

The largest part of my time in lab this week was spent observing a previously unidentified organism in my MicroAquarium. For the first time this week, I observed Dileptus (identified in fig. 391 of Freshwater Invertebrates of the United States: Protozoa to Mollusca by Robert W. Pennak) a large ciliate (it can be up to 1 mm in length) with a proboscis and a mouth at the base. Shown below is video of this organism, displaying the cilia lining its body and its distinctive mouth, as it interacts with a rotifer.

Week 3

Last week's addition of water from source # 13 appears to have greatly improved the amount of variety within my MicroAquarium. I observed larger numbers of many of the organisms I identified last weeks. Specifically, I saw several examples of the rotifer, Lecane, which is pictured in last week's post. Second in number to the rotifers were Halteria; I saw many of them this week. I also saw more of the vorticella I've seen the past few weeks, as well as several small single celled critters. In the sediment at the bottom of the acquarium I saw a few nematodes. Clustered near plants a and b, I saw several Paramecium, as identified in the Biocam poster Pond Life I Smaller Microlife and some other varieties of rotifers, identified in the same poster. Some of these rotifers were smaller than the Lecane, with bodies that were more elongated. Look for pictures of these and other organisms in next week's post.