Final viewing

I viewed my aquarium again on Wednesday, November 12th, 2008. It had been over a week since my last viewing. This session had more of a somber feeling as it was the last time that I would be examining my aquarium. The atmosphere seemed to lend itself to this somber feeling. There were only a few students in the lab this time, and there seemed to be less activity in the tank itself. There was definitely less sediment in the bottom and also less water due to evaporation.
The rotifers also seemed to be fewer and farther between. Most of the shelled rotifers were smaller and mainly stayed close to the plant material. There were also less Epistylis and Philodinas. The few that I did see had grown quite fat. At one point, I thought that I had found a new kind of organism, but Dr. McFarland assured me that it was only a rotifer in the process of dying.
Though the number of rotifers was declining, there seemed to be many new organisms ready to take their place. The water in the lower half of the tank was filled with fine hair-like structures. At first, I was not that impressed until I noticed that some of the shorter strands were moving. Dr. McFarland let me know that these were strands of cyanobacteria.
Among the strands of cyanobacteria were several very handsome paramecia and a swarm of small oval ciliated protozoa. There were also several long necked organisms that had peaked my curiosity. I had seen one or two before, but was never able to identify them before. I had to ask Dr. McFarland. He identified them as Lacrymaria, and indeed they matched the picture found on page 138 of Free-Living Freshwater Protozoa by D.J. Patterson. The lacrymaria are funny little organisms that look like a worm that has swallowed a Christmas ornament. They reminded me a little of the Loch Ness Monster with their pointed teardrop shaped body and long searching neck.
Sadly, that was all I had time for that day. It has been a lot of fun discovering all these tiny creatures inhabiting ordinary spring water. I’m not sure what will become of our aquariums after this. For a little bit, I wish I could keep mine, but since I don’t have a microscope at home, I’ll just have to let it go. Maybe I’ll get some Sea Monkeys instead.