Stichotrich
Encyclopedia
Ciliate
The ciliates are a group of protozoans characterized by the presence of hair-like organelles called cilia, which are identical in structure to flagella but typically shorter and present in much larger numbers with a different undulating pattern than flagella...
protozoa
Protozoa
Protozoa are a diverse group of single-cells eukaryotic organisms, many of which are motile. Throughout history, protozoa have been defined as single-cell protists with animal-like behavior, e.g., movement...
, included among the spirotrich
Spirotrich
The spirotrichs are a large and distinctive group of ciliate protozoa. They typically have prominent oral cilia in the form of a series of polykinetids, called the adoral zone of membranelles, beginning anterior to the oral cavity and running down to the left side of the mouth. There may also be...
s. Like the hypotrich
Hypotrich
The hypotrichs are a group of ciliate protozoa, included among the spirotrichs. Most are oval in shape, with a rigid pellicle, and have cirri distributed in isolated tufts on the ventral surface of the cell. Some also have dorsal cilia, which function as sensory bristles. Euplotes and Aspidisca...
s, with which they were originally classified, they have body cilia fused into cirri, but these are mostly arranged into rows, running along the ventral surface or edges of the cell. Most stichotrichs are flattened and reasonably flexible. Stylonychia
Stylonychia
Stylonychia is a genus of ciliate, included among the stichotrichs. It is very common in fresh water and soil, found on filamentous algae, surface films, and among particles of sediment. They can also be found swimming on/through decaying vegetation and pond scum floating through the water...
and Oxytricha are representative genera
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
. Some evidence suggests that the hypotrichs may be paraphyletic to them, and that they in turn may be paraphyletic to the oligotrich
Oligotrich
The oligotrichs are a group of ciliate protozoa, included among the spirotrichs. They have prominent oral cilia, which are arranged as a collar and lapel, in contrast to the choreotrichs where they form a complete circle. The body cilia are reduced to a girdle and ventral cilia...
s.