Tuesday, Nov. 13-Week 5

1: The overall environment of my Microaquarium seems calmer and less active. There are still lots of vorticella (on the moss), diatoms (spread through any open space in aquarium), and cyanobacteria (filaments have also spread out everywhere in aquarium).

2: The nematode population is most dense this week--I viewed at least 50 nematodes, squirming in place, concentrated at the bottom and around the moss, but scattered throughout the aquarium.

3: There seems to be less rotifer activity, most of the smaller rotifer species have died off, though the cyclops population still seems strong; there are more baby cyclops than adult cyclops.

4: PROTONEMA: I was able to identify protonemata extending off of the moss today! The green/brown network of long filamentous multi-celled structures are differentiable from cyanobacteria in that the cell walls are at diagonal, not perpendicular, angles with the filaments. The earliest stage of the bryophyte life cycle, these haploid structures develop out of spores, and will soon grow into the leafy gametophyte. This is exciting, I get to see what we're learning about (moss life cycles) in action!















^protonemata

Tuesday, Nov. 6-Week 4

***After feeding, did things multiply/grow/reproduce at a faster rate?? It seems so. I identified many more diatoms, rotifers, nematodes, vorticella, and seemingly most other organisms in the system.

1: Copepod Cyclops BABIES!
I encountered many, many cyclops babies. There were no baby cyclops last week, but after being fed, the cyclops seemed to reproduce quite readily. These young organisms look different from the adults with five "limbs" branching out along the front and sides of the body. They are slower and do not move in such frantic, sudden darts, but more of a steady slow pace. I found this concentrated towards the bottom of the aquarium, but there were actually several all over. They are non-green, multicellular, and soon to be full grown, larger cyclops. The cyclops population appears to be taking over the other rotifer populations.














2: Rotifer Ptygura:
This rotifer was anchoring itself onto a piece of difflugia (?) near the top of the aquarium. It had clearly visible cilia around it's "mouth" that spun around, vortexing food particles towards the opening. It was the only one of it's kind that I saw. It was tan (non-green) in color, multicellular, and drifted back and forth in the water. It seemed quite content on this difflugia, as it did not move the whole time I viewed the aquarium, whereas all the other rotifers were spastic and constantly darting around.





















3: Nematodes:
I saw two nematodes today for the first time. One was trapped/captured by something, and was frantically worming around, (unsuccessfully) trying to whip free. They were both a dark-greyish color with round, multicellular, long bodies. Their body structure can be described as a "tube within a tube;" they have digestive, nervous, excretory, and reproductive systems, but no circulatory or respiratory system. They are the most abundant animals on the planet! (http://nematode.unl.edu/wormgen.htm)
















4: OTHER PHOTOS OF MICROAQUARIUM:














^two Vorticella anchored on the central moss.

















^mother Cyclops carrying egg sacs (top view).
















^mother Cyclops carrying egg sacs, eating (side view).