Day 27. Tues Nov 8, 2011

This week there was much less diversity and activity in my aquarium. It actually took me a few minutes to even find any organisms that moved. However, even though there was less diversity within my aquarium, there were plenty of organisms for me to identify. The Tachyosoma from the week before were gone, but there was another organism that greatly resembled them. In fact, I mistook it for the Tachyosoma, but Dr. McFarland assured me it was not the same organism. I identified it as Euplotes (Patterson 1996). These creatures crawl instead of swim, according to Free-Living Freshwater Protozoa: A colour guide. The organism is shown in Figure 1.

Figure 1. Euplotes (Patterson 1996, Fig. 260).

This was not, however, the first organism that I noticed in my aquarium. I saw Bursaria first but was not able to get a picutre (it quickly swam away and I didn't find it again). It was a some-what large organism with a long flagella. Among the other organisms I identified was Paramecium: A fat grub-like organism that moved really slowly (Patterson 1996). It is viewable in Figure 2.

Figure 2. Paramecium (Patterson 1996, Fig. 346).

Litonotus, pictured in Figure 3, was a smaller looking version of Paramecium and swam a little faster (Patterson 1996).

Figure 3. Litonotus (Patterson 1996, Fig. 285).

Next I identified Petalomonas (Patterson 1996). This organism was more similar to the Bursaria, but it was much smaller and not nearly as fast. There were a lot of these guys, but capturing an image that illustrated them well was a challenge. Figure 4 was my best attempt.

Figure 4. Petalomonas (Patterson 1996, Fig. 83).

One of the neatest organisms that I found was a free-swimming algae called Phacus triqueter (Forest 1954). It stood out from the rest of the algaes and even the protozoa. It was a shade of green that differed from every thing around it. The way it swam was cool too. It was spinning as it swam, so it looked almost like a coin being flipped (It was a flat organism, hence the resemblance of a coin). Figure 5 doesn't show the organism's shape well, but it was the best image that I could manage.

Figure 5. Phacus triqueter (Forest 1954, Fig. 419).

Sournces:
Forest, Herman Silva. 1954. Handbook of Algae. Knoxville (TN): University of Tennessee Press. 296 p. Fig. 419.

Patterson, D.J. 1996. Free-living Freshwater Protozoa: A Colour Guide. London (England): ASM Press. 55-154 p. Fig. 83-346.