Week2 10/25/11

Death is a natural cycle of life, but scientifically speaking death in mass is a curious observation.
This week in the microaquarium, contrary to the abundant numbers observed last week, it appeared that all but one Ostraocoda had died. It is important to note that large Ostracoda shaped vessels were found, unresponsive to light and completely immobile at the bottom of the tank. It was thereby concluded that these vessels were probably the remains of the formerly abundant Ostracoda.

On a different note, for reasons unbeknownst to the observer there was an explosion of protozoa activity in this weeks observations. One observed Protista, not present a week before, was Vortecella. This Protista anchored itself to the muddy bottom or to the plant bodies with a long thin tail like structure. It also used rotating cilia on the top of a cup shaped portion to spin water through its clear body in order to extract particles from the water medium as food. Other single celled organisms were observed though not identified.

As to the Ostracoda's mysterious and unresolved dissappearance, two conclusions may be met. 1) The Ostracoda have either mastered the highest form of hide and seek or 2) Some change or structure within the environment has caused them to become quite endangered within the aquarium.
As to the reason behind this endangerment the observer has only a few theories as of late: given that the bodies of the Ostracoda were found and not devoured, the cause of the deaths must be due to environmental changes rather than predatory activity (or hide and seek). The water levels in the tank had subsided a bit in week one and new water had been added to the tank by week two. As the observer did not add said water it is possible that the new water could have changed the environment sufficiently to harm the Ostracoda. Another theory is that the plant material, not found in the parent location for this water medium, could have been non-conducive to the Ostracoda's internal systems as they were seen feeding on both sets of plants.  

As a final observation, it is important to note that neither theory is regarded as conclusive and that further observation will continue in the weeks to come.