10-21-08
Today in the lab, I observed my aquarium under the microscope. I immediately saw two organisms floating independently of the plants, and they resembled pea-pods. They moved through the water, but seemed to float rather than swim. With the aid of my lab instructor and some books, I found out that this unicellular type of microorganism is called a closterium. It is a type of algae, and it divides by fission. It is a crescent shape with circular choroplasts, and the circular shape in the center is known as its nucleus. This type of organism was not seen in great quantity (only 2), since it had only been days since my aquarium was built.
Works Cited:
1.Graham and Wilcox "Algae," p. 102, Prentice Hall Publishers, 1954
2.http://en.wikipedia.org/wiki/Closterium
3.http://botany1112008.blogspot.com/2008/10/botany-111-2008-term-project.html
10-23-08
Today I saw a strange organism on one of the plants. It looked attached to the plant (thus making it stationery), and the top of it appeared to be moving. My lab instructor told me this was Philodina, a type of rotifer. The organism acts as a vortex; it sucks in water, and the water passes through the organism. This function allows it to digest any nutrients found in the water. The motion I saw at the top of the organism was produced by the cilia of the organism. I only saw one of these.
The closterium organisms I saw previously had increased in quantity (around 4), and they seemed larger than when I last saw them.
While viewing my aquarium under the computerized-microscope, I continued to search for any possible signs of life. Suddenly, a giant larva wiggled across the screen, and I was scared out of my seat. My lab instructor aided me with some illustrations from a book, and I was then aware that this was Chironomus, a midge larva. This was a lone organism; there were no others of its type. It was larger than any other organism previously seen. This organism would alternate environments; it would swim quickly through the water, but it also crawled on the plants. This larva eventually grows to become the chironomid fly.
Works Cited:
1. Ward, Henry B. and Whipple, G. 1918. "Fresh-Water Biology" p.915/1111, Published by John Wiley
2. http://en.wikipedia.org/wiki/Rotifer
3. http://en.wikipedia.org/wiki/Chironomidae
10-30-08
While in the lab today, I noticed that the midge larva had died, and was now at the bottom layer of the tank. However, there was a new type of organism feeding on the deceased larva. I saw some paramecia enjoying the meal, while other paramecia were swimming rapidly through the water. The paramecium is covered in cilia, which enable it to move through the water so rapidly. It's a unicellular organism, even though it has two nuclei. It has a semi-green appearance, but only because of the food it carries. So it is not a photosynthetic-autotroph, but instead a heterotroph. Its habitat of preference was at the bottom of the tank.
An interesting new type of organism was seen attached to debris (stationery organism). It was a long, slender organism, with a bell shaped "head" at the end. Mr. McFarland told me that this was a Vorticella, and he told me to tap the aquarium. When I did, the Vorticella vanished, and then reappeared. It's sensitive to touch, which explains this phenomenon. This organism wasn't seen in great quantity, since I only saw about 3 of them. It's ability to collect food makes it heterotrophic, and not an autotrophic organism. Below is a photogaphic sequence of its shrinkage and reappearance.
I also saw a new type of rotifer today, but I could not identify which type it was. However, unlike the Philodina I've seen, this one swam through the water instead of attaching to a plant. It has a long flagella, enabling it to move through the water. It was a multicellular organism, and was one of the other heterotrophs feeding on the midge larva. Its habitat of preference was the bottom and the middle of the tank.
Works Cited:
1. Plaskitt, F.J.W. 1926. "Microscopic Fresh-Water Life" Chapman & Hall Publishers p. 134/278, p. 205/278, and p. 159,160/278
2. http://en.wikipedia.org/wiki/Image:Vorticella_sequence.JPG
3. http://en.wikipedia.org/wiki/Paramecium
4. http://en.wikipedia.org/wiki/Rotifer
11-6-08
Every time I visit the lab, there's always something new to observe. Today, I was surprised to find a huge population of diatoms in the aquarium. They were scattered in colonies towards the bottom area of the tank. The most prominent diatom seen was Thalassiothrix Frauenfeldii. These diatoms remained stationery, and were unicellular. They are photosynthetic autotrophs. they belong to the kingdom protista, and the phylum Bacilliarophyta. A photo from the lab is illustrated below.
I was also fascinated when I saw Coleps in my tank for the first time. They are of the protozoa, and they "buzz" through the water, like a swarm of bees. They are unicellular heterotrophs, and by feeding on decaying matter, they are also saprobes. The organism is a brown grenade-shape, and its preferred habitat was at the middle and bottom of the tank. I saw several swarms of this organism. Here is a photo of the Coleps (not from the lab).
The third organism observed today was the ciliated protozoan Chlamydodon. This organism is unicellular, and its surrounding cilia allow for rapid movement through the water. It is also unique, being a flat microorganism. It was a non-green heterotroph, and preferred the bottom of the tank as its habitat. This organism was seen in great abundance. I have included a photo of one from the lab.
With every week, I see something new. I can hardly wait to see what will be revealed next time!
Works Cited:
1. http://www.gpmatthews.nildram.co.uk/animalcules/coleps03.jpg
2. Raisnis, K. G. and Russel, B.J. 1998. "Guide to Microlife," Publisher: Franklin Watts, p.90/287 & p.179/287
3. http://en.wikipedia.org/wiki/Diatom
I was also fascinated when I saw Coleps in my tank for the first time. They are of the protozoa, and they "buzz" through the water, like a swarm of bees. They are unicellular heterotrophs, and by feeding on decaying matter, they are also saprobes. The organism is a brown grenade-shape, and its preferred habitat was at the middle and bottom of the tank. I saw several swarms of this organism. Here is a photo of the Coleps (not from the lab).
The third organism observed today was the ciliated protozoan Chlamydodon. This organism is unicellular, and its surrounding cilia allow for rapid movement through the water. It is also unique, being a flat microorganism. It was a non-green heterotroph, and preferred the bottom of the tank as its habitat. This organism was seen in great abundance. I have included a photo of one from the lab.
With every week, I see something new. I can hardly wait to see what will be revealed next time!
Works Cited:
1. http://www.gpmatthews.nildram.co.uk/animalcules/coleps03.jpg
2. Raisnis, K. G. and Russel, B.J. 1998. "Guide to Microlife," Publisher: Franklin Watts, p.90/287 & p.179/287
3. http://en.wikipedia.org/wiki/Diatom
11-13-08
This was the final week of observation, and I saw some interesting things in the aquarium. Looking along the mud, I noticed several Nematodes for the first time. They're all very similar in their appearance, so unfortunately, I am unable to name a specific species. They were only seen living in the mud of the aquarium, since their rapid, wormlike movements provide no transportation through free water. They are all non-photosynthetic heterotrophs and, interesting enough, may even feed on their own kind in some cases. They're mostly transparent in appearance, with the exception of their brownish intestines. Having a digestive system organs such as this, it is clearly a multicellular organism. This microorganism was seen in a moderate amount. I have included a photo of a Nematode below (not my own photo).
I was also pleased to see a new species of Diatom present in the aquarium, Fragilaria Construens. It differs greatly in appearance from all the diatoms seen previously, with it's squarish shape and striped pattern. Oddly enough, this organism was found in a small area under the mud of the aquarium. Like most other Diatoms I have seen, this one was a stationery organism. Despite its non-green appearance, it is indeed a photosynthetic autotroph. It is a unicellular organism like many other diatoms, but diatoms of this type can connect together into a filament. Below are two photos (not from the lab); a photo of an individual, and a photo of a filament.
Also new to the aquarium was the green algae Coleochate Scutata, belonging to the algal phylum Chlorophyta. It is a photosynthetic autotroph, which is especially obvious given its green appearance. It wasn't very common in the aquarium; I only saw one in the middle of the tank. With its greenish, round appearance, it greatly resembles Volvox, but shouldn't be mistaken for it. Its sexual reproduction is oogamous, meaning the female egg is larger than the sperm and non-motile. It also has an interesting way of reproducing asexually; biflagellate zoospores are produced by the vegetative cells. The entire organism itself is stationery, but its zoospores move with the aid of their flagella. It is obviously a multicellular microorganism. Below is a photo of the organism (not my own.)
Last but not least, I was lucky enough to have spotted Volvox, which also belongs to the algal phylum Chlorophyta. This green algae is unique for being colonial. That is, individual cells are connected by cytoplasmic threads. It's method of sexual reproduction is also oogamous, and also releases haploid zoospores during asexual reproduction. Like the previously mentioned algae, it wasn't seen in great numbers, only one. Like all the green algae, it is a photosynthetic autotroph. It is multicellular, and it doesn't move. I have included an image below, from a website.
Works Cited:
1. Whipple, G.C. and Ward, H.B. 1918. "Fresh-Water Biology" p.459,460/1111, published by John Wiley.
2. Vinyard, W.C. 1979. "Diatoms of North America" p.116, 117/119, published by Mad River Press, Inc.
3. Round, F.E. 1990. "Diatoms" p.354, 355, 356/747, published by Press Syndicate of University of Cambridge
4. Bold, H. C. and M. J. Wynne. 1978. Introduction to the Algae. Published by Prentice-Hall, Inc.
5. http://craticula.ncl.ac.uk/EADiatomKey/html/taxon13770010.html
6.http://www.gpmatthews.nildram.co.uk/animalcules/coleochaete/Coleochaete_scutata_001.jpg
