observation five 11/10/10

Observation: Today when I came upon my micro-aquarium the top was off and it looked like a little of the water had evaporated.  None the less when I looked at my micro-aquarium under the microscope I did not see the dead zone I observed last week. This week some of the organisms I observed in passed weeks had returned although not all of them. I still did not see any Vorticella. I did see a Marochaetus (Donner) and some Rotifers moving around this coincided with the fact that I did not notice any Actinophrys, which were the only organisms I saw last week.

   

Marochaetus prefer to live in mud or places with lots of cover or sediment.

  Rotifer are small aquatic organisms that can live in a variety of environments such as arctic lakes. They use their tail to propel themselves though the water in search for food (Gilbert).  

Citations: 

Dormancy in Rotifers

John J. Gilbert

Transactions of the American Microscopical Society
Vol. 93, No. 4, Symposium: Perspectives on the Biology of Dormancy (Oct., 1974), pp. 490-513

Published by: Blackwell Publishing on behalf of American Microscopical Society

Stable URL: http://www.jstor.org/stable/3225154

Donner, Josef. Rotifers. Frederick Warne & Co. 1966

observation four 11/03/2010

Observation: Two weeks fallowing the addition of the Betta Food, The Number of species I observed has dramatically decreased.  I say non of the species I have seen in the previous three weeks and of the few individuals I saw most were to fast to really get a good look at.  However I did find a new organism that I have not seen before.  A Actinophrys (Patterson, 1992), I only saw one of them.  I do not know exactly why the species richness has decreased.  A hypothesis to why the species has decreased may be because the amount of food available in the ecosystem has diminished causing a mas die off.  Another hypothesis to way the observable species richness has decreased could be the Actinophrys.

   The figure to the left is an Actinophrys. Actinophrys is a predator that uses its long spike like arms to capture food (Bovee 1971).
















Citations:

• Feeding on Gastrotrichs by the Heliozoon Actinophrys sol
• Eugene C. Bovee and Dean L. Cordell
• Transactions of the American Microscopical Society
  Vol. 90, No. 3 (Jul., 1971), pp. 365-369
  (article consists of 5 pages)
• Published by: Blackwell Publishing on behalf of American Microscopical Society
• Stable URL: http://www.jstor.org/stable/3225197

 Patterson, D.J. Free Living Freshwater Protozoa. Manson Publishing. 1992.