Vorticella Sighting October 29, 2008

Although the Cyclops was missing in this observation, several Vorticella were identified using 40x magnification and the reference book The Ciliated Protozoa (John D. Carliss, 1979 London,Pergamon Press 2nd edition page 273). At first observation, there were at least 6 of these, mostly around the center of the tank, seemingly attached by stalks to the Utricaria plant. Several were apparently light green, others with no discernable color. The outer "lip" is covered in cilia, giving the appearance of a spinning outer "gear" which is apparently used for motility as well as feeding. When shaken or disturbed, these organisms contract into a smaller, spherical shape and do not move again for several seconds. Using resources cited below, it was surmised that these are adult Vorticellae, that the stalk is called a Spasmoneme, and that they are free-swimming until adulthood when they have found an appropriate food source and something to use as an anchor.
"VORTICELLA
Genome Structure
Like some other ciliates, Vorticella has a deviant genetic code. UAA, a traditional stop codon, instead translates for glutamate.
The small subunit rRNA (SSrRNA) gene has proved crucial for distinguishing between Vorticella species. Because different species are physically very similar, it is difficult to tell them apart by morphological characteristics alone. SSrRNA has proved a much more effective method of classification and identification.
Cell Structure and Metabolism
Vorticella are sessile organisms. However, young Vorticella are free-swimming. Adult forms attach to substrates with contractile stalks. This stalk is a filamentous organelle called the spasmoneme. Adults can also be free-swimming if these stalks are cut. They can also detach themselves if food supplies are scarce and they need to find a new location. The spasmoneme has three cellular membranes, an extracellular matrix, and an outer sheath. These stalks coil upon contraction. It is believed that the contraction is a defense mechanism to protect Vorticella from environmental hazards such as turbulent water. Contractions also help Vorticella capture food.
Vorticella are referred to as Peritrichs, meaning that their cilia are concentrated around the mouth end of the organism, but nowhere else on the body. In the event that Vorticella becomes motile, temporary cilia will form around the body. However, once the organism has anchored itself, these cilia will disappear.
Vorticella are heterotrophic organisms. They prey on bacteria. Vorticella use their cilia to create a current of water (vortex) to direct food towards its mouth.
Typically, Vorticella reproduce via binary fission. The new organism splits from the parent and swims until it can find something on which to anchor itself. They are also capable of sexual reproduction. "
From:http://microbewiki.kenyon.edu/index.php/Vorticella


Also in evidence were a multitude of small, very fast Paramecia as well as brownish, fairly stable diatoms.