Lab Observations 2

Made: 10.22.13
     My second set of MicroAquarium observations were made today, first using the light microscope and later, the camera/microscope. Immediate noticeable changes in the MicroAquarium were made. Utricularia gibba, the plant, has now taken on a slightly browned appearance (McFarland, 2013).  The aquarium also went through several changes with the "non-green" organisms. First of all, no organisms were observed that had died and sank to the bottom (luckily), but new organisms have appeared. This includes the addition of at least one Philodina sp., a single celled organism I will discuss momentarily (Pennack,1953). There may have been even another type of rotifer which I was unable to capture to identify properly so the  identification may be incorrect. Also, I should note that my lab instructor pointed out a possible "Carpenter's Ruler", a thin stick-like organism, however no movement was observed and a proper identification was not mad to prevent the possibility of incorrect identification. These new organisms tended to the bottom of the aquarium, where the debris lay.  The single cyclops, now assuredly  identified from the previous observations taken, has gained a faster and more sporadic pattern of movement, so much so I was almost unable to view it (Rainis & Russell,1996). In the case of the many flagellates/ciliates (first sited 10/17), while the speed of the organism stayed relatively the same, they had a more varied tendency of location.
      The Philodina sp., which I referred to earlier, not only had a very strange movement, which consisted of what appeared to be eating the dirt/debris extremely rapidly, but was also hard to identify and observe. When I first spied what I BELIEVE to be this organism, I showed it to the instructor who identified it as a rotifer. A bit later, I noticed it again. It had moved locations without leaving the debris area ( I could have mistaken two completely separate organisms). However, it appeared larger and was "eating" more rapidly than originally.  The "stomach" area and in fact, the whole organism was rather transparent which allowed me to see literally inside the organism as it ingested the debris (Fig. 1). The appearance of it was interesting, indeed. The lab instructor and I looked up a diagram of Philodina sp., and compared it to the one in my MicroAquarium. We noticed that mine seemed to have three or four "toes" while the average specimen has two (Fig 2.). This, accompanied with the large size and strange movements, led me to hypothesize that the organism was currently participating in asexual reproduction. After a bit of background research on Philodina sp., I found that, "Several types of reproduction have been observed in rotifers. Some species consist only of females that produce their daughters from unfertilized eggs, a type of reproduction called parthenogenesis. In other words, these parthenogenic species can develop from an unfertilized egg, asexually (Speer, 2000)." This leads me to further believe that it is likely the specimen was exhibiting the above  process and perhaps new specimen of Philodina sp. will be available in my aquarium for observing next week.
              I managed to capture a couple of pictures of the Philodina sp. using the cameras attached to the light microscope. The pictures are documented below as Fig 1. and Fig. 2. Notice the small tentacle-like protrusions in Fig. 1. These were in constant motion- ingesting debris or not.

Fig. 1. Shows Philodina sp. with ingested debris and
tentacle-like protrusions on left near mouth (Pennack, 1953).

Fig. 2. Shows Philodina sp. specimen with multiple "toes" (Pennack, 1953).