Higher order taxa:Eukaryota; Alveolata; Ciliophora; Oligohymenophorea; Peritrichia; Vorticellidae.
Description and Significance
Vorticella are members of the phylum Ciliophora. In some ways, they resemble members of the phylum Suctoria. However, there are major morphological differences between these two types of organisms. It is the unique structure of Vorticella that distinguishes them from other ciliates.
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 characterstics 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 extracelluar 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 organsims. 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.
EcologyVorticella are aquatic organisms, most commonly found in freshwater habitats. They attach themselves to plant detritus, rocks, algae, or animals (particularly crustaceans). They are individual organisms, but often can be found in colonies. However, these are not true colonies, because each individual retains its own stalk. Vorticella are therefore free to separate from the colony at any time.
Updated June 24, 2005
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