Observations for week 3 (11/03/2011)

     Little has changed with in the micro-aquarium this week since the last observation.  The food pellet is still not entirely dissolved at the top of the water line.  The water is about a quarter down from where i left it, similar to how it was the week before.  The Utricularia gibba is almost entirely dead and much of it has actually begun breaking down, forming a substrate for some of the protists to anchor to.  The Amblestegium sp. is only about half dead and even has some lighter green areas forming on it.  These discolored segments could potentially be new growth or older ares which are experiencing the onset of chlorosis.
     Less of the Vorticella sp. are found attached to the stems of the plants and more of them seem to have become entirely free floating, relying on no anchor what so ever.  They appear to have been replaced on the plants by thin, red filamentous growth.  Although they are still by far the most abundant organisms,  the Vorticella are no where near as densely populated as they were last week.  Several Seed Shrimp (Ostracoda sp.) are now visible.  They vary in size with several small ones free floating and 4 or 5 larger ones buried in the sediment.  There were also several unidentified paramecium floating around, one of which is pictured below.
      Like usual I filled the aquarium up and replaced it on the tray when finished.

Fig 1. Vorticella sp. (Patterson 1996, Fig. 232)

Fig 2. Paramecium sp. (www.bio.umass.edu/biology/conn.river/paramecium.html)