Week 4: The last obeservation

Well this is the final observation for this MicroAquarium. From Week 3 til now (Week 4) there are still as many Rodifers as there were last week, but some organisms did die. One nemotode and about 10-15 Arcella were in the bottom of the tank. The cyanobacteria, on the other hand though, exploded. In addition, there several fragments and pieces of cyanobacteria everywhere in the tank. There were also clumps of cyanobacteria everywhere, like the picture to the left. They also seem to stay near the flowering plant in the middle of the tank possibly for photosynthesis purposes. The moss has declined slightly in size probably due to all the different organisms feeding off of it. One more thing about the Arcellas, they are different from the other organisms in that they are found throughout the entire tank and even though some of them died, for the most part they multiplied greatly. The vorticella(Patterson and Hedley pg 113 Fig 233) are extremely interesting to watch eat because they contract then release to digest food. The Chilonomas and Colpidiums are still just as numerous as ever and the huge Philodonia is still alive and well. The Peranema are still alive and doing the same thing they were last week and the week before. The dinoflagelates are still numerous as well. Fiunally, the Phacus and Euglena are still thriving and innumerable as ever.

Overall, the population increased and thrived. The most prominent and prosperous were the larger organisms, such as the Rodifers and Nemotodes. The exceptions to this are the cyanobacteria, the Colpidiums, and the Chilonomas, which are extremely tiny, but as mentioned before they were sitll very numerous. Also stated before is that the Arcellas lost some of their own but for the most part multiplied tremendously. The only organisms that did not have a dramatic change were the Phacus and Euglena and the moss and flowering plant in the tank. Everything else increased in size, even if they did lose some of their own species. I never knew that there were so complex ecosystems in water. I have learned so much from this interesting and informative observation over this past month.