Week #4 MicroAquarium Project

Stenostomun sp.

This week was extremely interesting. There was a lot of different activities going on in the aquarium and with the help of Mr. Kenneth Mcfarland I was able to identify the variety of organisms in the aquarium. I was able to observed many different activities compare to last week. First, I noticed a lot of floating debris in the bottom part of the aquarium (maybe dead organisms). There is also a large amount of small organisms moving very fast they almost look like invisible thread. There is also a large amount of cyanobacteria as well. I took both of these pictures they are identified as Stenostomun. This organism "Stenostomun" is pretty big compare to other organisms within my aquarium, like rotifers, snails and others. What caught my attention about this organism was the big spot in the middle. My first guess was that the organism had digested several organisms or that it was pregnant.  Although I observe the stenostomum digesting different parts like algea and other organisms, I was not sure of what it was. I did notice that this particular organism was very active on one side of the aquarium, to be specific, I only saw it near plant B. There are several Stenostomum in my aquarium but only one with this black spot in the center or almost the center. "Hypodermic impregnation appears to be the role in Stenostomun. A single egg is ripened in each ovary during the reproductive season. It is fertilized inside the body and is liberated to the outside by a rapturing of the body wall" (Smith, Pottswald). The movement is medium motion but steady and hardly stood still. From what I have observed in last few weeks, this is the largest organism in my aquarium with waters from the Holston River. There are several snails but they do not wonder around much as does the Stenostomun. The snails spend a long time on the same spot and they seem to be hungry always. Also, they are more frequent in the middle of the aquarium. Overall, my aquarium seems to have a variety of organisms and I have to agree that it is a whole new world after observing my aquarium under a microscope. This is something that needs to be seen to believe it. I never thought that so many small organisms could be in such a small amount of water and be able to live and hunt for food. Inside that aquarium lives a whole different world.


Citation:

Smith D. Pennak's Freshwater invertebrates of the US, 4th ed. pg 89

Ward H. Freshwater Biology pg 336