Week 5: Observing the Aquarium

While examining my microaquarium today, I noticed that there were several different kinds of rotifer. When I asked about these rotifer, I was told that over time, rotifers start to change in the aquarium and there is more of an abundance of them. One of the rotifers I happened to notice was the Trichotria. These rotifer are Australian and have a rather strange looking dorsal (Kose and Shiel, 1989; Fig. 16.1). It has a unique set of spike-like strands coming off the top of its body.

Rotifer (Trichotria):

Like one of my previous posts, I was able to find a rather large amount of vorticella present. I made a point to tap the glass and watch as they unfolded themselves out of defensive position. Their lips pop back out and adjust the current around them.

Vorticella (Week 5):

The last thing I noticed was a "splotchy" looking organism called an amoeba. This particular amoeba had one nucleus, even though they often have many (Patterson, Fig. 194-197; 1998). This amoeba has a folded nucleus and is rapidly digesting the food around it. This process allows it to become large and accumulate. It is easy to notice the several large vacuoles inside of it.

Amoeba:

Though it seems that organisms tend to increase most weeks, I have found less present this week. There are mostly just rotifers, amoebas, nemotodes and shrimp seeds. There does not seem to be anything new. I noticed right away that there were not as many organisms swimming around, and thus less to observe.

Week 4: Observing the Aquarium

Today, when I examined my microaquarium, it was full of many organisms. A majority of the organisms have moved to the food pellet and have been moving around it. Many of these organisms are small and circular, but there are a few larger organisms as well.

One of these larger organisms that I found was an aeolosoma. These organisms are a type of annelida that are strictly aquatic (Pennalt 1989; Fig. 1, 291). The organism is sometimes found in mud and debris, but in this case was found in masses of filamentous algae. By looking at the picture below, it is easy to see its internal organs, which is a common trait of its species.

Aeolosoma:

Aeolosoma (Head):

Another rather large organism was a seed shrimp. Seed shrimps are seldom more than 3mm long and, in this case, are a dark brown (Pennalt 1989; Fig. 444). It has a lime-impregnated valve that consists of an inner and outer plate. Between these two plates is a skin fold that secretes value materials. They mostly eat bacteria, algae, molds and find detritus.

Seed Shrimp:

The smaller organisms consist of several euplotes. These particular euplotes have cilia and have a structural groove (Patterson 1998; Fig. 260). They are a type of hypotrich cilate and can make a current of water using membranelles. There are also ventra cirri on the organism.

Euplote:

Multiple Euplotes: