Observation #4

This observation was made exactly 4 weeks after the creation of the MicroAquarium.

As my last observation, I would like to spend some time discussing several organisms that have been present and multiplied throughout the duration of this term project. These include: the rotifer, the peritrichs, and the ostracod. (photos were taken by me)

Firstly, the Rotifers:

Rotifers are part of the Phylum Rotifera. The name is derived from Latin, meaning "wheel-bearer", which most likely refers to the rapid movement of the cilia around the mouth. They use these long, coronal cilia to catch food by creating a vortex which draws water and food particles into the rotifers complete digestive track. These multicellular, microscopic animals are found in either still or flowing freshwater, and prefer mosses and lichens as anchoring ports. Their mostly soft bodies are composed of four basic regions: corona (crown), trophi (jaws), pharynx (throat), and foot (attachment feature). Because of their small size, they are often found as fossils. The oldest reported fossil was found in Dominican amber.

Resource: www.ucmp.berkley.edu/phyla/rotifera/rotifera.html

Secondly, Peritrichs:

Peritrichs are Protozoa in the Ciliates group. They frequently exist as separate, stalked organisms or branched colonies. These stalks attach to any submerged plant material and use cilia around the mouth of the peritrich to create a food-bringing current. The classic organism is called the Vorticella which means "bell animalcule", referring to the shape it takes when fully extended. Found in freshwater, they eat mostly bacteria, algal unicells, and smaller protozoa. The stalk is contractile and can pull into a tight spiral if the organism is disturbed. This contracile action holds the record for the fastest action in the animal kingdom! If ever the peritrich needs to find a new, more favorable enviornment it can detatch itself and swim freely elsewhere. In this state it is referred to as a telotrach.

Resource: www.micrographia.com/specbiol/protis/cili/peri0100.htm

Lastly, Ostracod:

Ostracods are crustaceans. Found in both fresh and marine water, ostracods are distantly related to the shrimp family. This similarity is more easily seen in the marine variety because of their larger size. The freshwater, like the ones in my aquarium are much much smaller. As observed, they tend to spend most of their time and energy along the edges, submerged in the debris and muck of the lower levels...not swimming freely in open water. Appendages extend from between the two halves of their carapace shell. This shell is somewhat patterned and not transparent, making it hard to see the internal structure of the ostracod. However, it is obvious that their level of activity is very high, as they are so hard to keep in your microscopes eye. their activity is ceaseless. If disturbed, they will clamp the two halves together for protection. I also observed the remaing exoskeletons left over from a moulting or from a dead ostracod whose internal remains have been eaten. Ghostly and transparent, these skeletal remains are only a vague memory of their former selves.

Resource: www.micrographia.com/specbiol/crustac/ostraco/ostr0100.htm

That's all folks!

Observation #3

This observation was made after three weeks from the start of the project. Although I saw many of my old friends, the rotifers, daphnea, and peritrichs, I became fascinated with a new organism. I spent the entire hour tracking and watching this creature. What first caught my eye was a wormlike movement, but what caused the movement was extremely large. Then, I saw more movement close by. It turned out that it was one organism, entertwined within the plant material. This thing was huge! At first glance, it appeared long and worm-like with tiny tufts of cilia along the lower portion of the tubular body. The "head" was rounded and had a hole that it used to suction and engulf other materials. It was possible to make out individual, globular divisions within the overall body of the organism. To move, the organism would contract. Anytime it came in contact with another living creature, it would quickly contract and slowly expand back out. Twice, I witnessed two of these organisms come into contact with one another. One would lead and the other would follow right behind. Once, they rubbed each other and one tried to engulf the other, failed, and "swam" away. I believe, after talking with Dr. McFarland, that it was an Analid in the Aeolosoma group. I was successful in engulfing a cyclops, failed at the attempt to engulf an anchored, whorling rotifer, and succeded in engulfing and digesting a flat worm. The anterior end had a brain, a cilitated pit, dosal blood vessel, esophagus, mouth, nephridium, and pigment globules. I loved observing this fascinating organism and a few pictures are included above.

Observation #2

This observation was made exactly 2 weeks after the aquarium was constructed: a food formula was added to the aquarium

Initially, the first thing I noticed was that there was, on the whole, a greater amount of movement and total activity. Everywhere I looked there was an organism or several moving about. Even after focusing in on a particular specimen, there was a continuous frenzy of smaller organisms shooting about in the enviornment.

I observed three new organisms:

Firstly, the presence of little bell-shaped, transparent extensions were seen attached/stemming from plant life. These, I believe, are in the Ciliates group and are called Peritrichs. A long, clear, slender tube connected the cup/bell shaped end to the plant life and they moved along with the movement of the water.

Secondly, a long wormlike organism moved rapidly through the water with snake-like motion. It would coil itself and then quickly straighten out. It curled in and out of plant life, was extremely thin and fast, and mostly clear in appearance. Though not certain, it appeared to be a roundworm. I observed 2 of these fascinating creatures.

Thirdly, I saw two organisms when appeared to be long tubes like worms but had little motorized spinners on the end with cilia attached. Because of these spinners, I wonder if they are not a type of rotifer with a hairy appendage that attached to plant life. Also, it was transparent.

In addition to these new discoveries, I once again observed the Ostracods. Their "split bean" appearance was easily spotted as they are large and have a vigorous movement system. Some were seen moving in and out of the bottom plant growth and another was seen stationed firmly to a leaf, its little cilia turning a mile-a-minute.

Generally speaking, the amount of life and overall activity seems to be increasing. I will try and post pictures soon.

Observation 1

This observation was made exactly one week and two days after the initial creation of the MicroAquarium. Firstly, there was an overall greater level of activity, movement, and presence of organisms.



Rotifers proved to be the organisms I saw the most, totalling five. They were also the quickest moving and were found in all areas of the aquarium. They were observed anchored and feeding to plant material in the open mid-section of the aquarium, along the bottom muck, and openly "swimming" throughout the water from destination to destination.



Several Daphnea corpses were seen left unattended and loosely attached or snagged. They looked like a bean capsule that was opened into two concave compartments with a clear, skeleton system springing beneath them. Three corpses were seen and two live individuals were observed.



Ostracots were seen (about 2 total). These creatures moved with motor-like motion. They were extremely fast and had whisker-like projections helping to move them along. They tended to burrow amongst the bottom muck.



There were various kinds of linear, tube-like filamentus creatures. Some appeared red, while others looked green. They seemed to form a network system where they would attach to one plant material than bridge the water enviornment to hook onto a different plant material. A short one was seen attached to a plant and its bottom cell was more swollen and contained more green substance (chlorophyll ?) than its top cells which were further from the plant material itself.



Lastly, an almost transparent wormlike organism was seen moving through the water. It was small and had a split tail (like a snake's tongue).



Overall, the majority of the plant life was seen on the bottom muck or in Plant A (the mossier of the two).

Starting MicroAquarium

The water source I used to create an environment in my MicroAquarium was labeled as number 9. I then placed two different samples of plant life, Plant A and Plant B. Plant A appeared to be thicker like moss, while Plant B was long, thin, and stringy. Along the bottom of the aquarium, a thin layer of muck/mud was carefully placed...enough to provide some nutrients and shelter, but not enough to obstruct viewing and observation.

After completing the set up of the MicroAquarium, I then observed it under a light microscope at 4x and 10x magnification. A multitude of creatures were seen swimming about, and the following inadequate/uneducated descriptions will be an attempt to describe them:
-a linear, worm-like organism was observed flailing about along the edges of the plant material; it was slighty tan in color, but see-through. It seem to contort and contract it's body to move quickly about. There were two observed during class time.
- a large, round, bulbous organism moved very slowly along the outer edges of the plant life; it was densely packed with a multitude of smaller compartments or particles; it seemed to move with the help of radiating little fingers/cilia
- an oval, mid-sized individual moved quickly through the water with the help of a distinct tail; it was clearish with an obvious red nucleus (perhaps); could possibly have been a Rotifer
- several long, multi-celled, chain-like organisms were observed. movement was undetectable and some were filled with chlorophyll green; some floated free while others extended off of plant material