Task: Question Answering
Input (English): Context: Telotroch is the free-swimming stage of members of the order Sessilida. Sessilida are ciliates of the subclass Peritrichia., The ciliates are a group of protozoans characterized by the presence of hair-like organelles called cilia, which are identical in structure to eukaryotic flagella, but are in general shorter and present in much larger numbers, with a different undulating pattern than flagella. Cilia occur in all members of the group (although the peculiar Suctoria only have them for part of the life-cycle) and are variously used in swimming, crawling, attachment, feeding, and sensation. All behavioral patterns are coordinated by signaling processes., The peritrichs ( Latin : Peritrichia ) are a large and distinctive group of ciliate protozoa . They are usually bell or disc shaped , with a prominent paroral membrane arising from the oral cavity and circling counter-clockwise around the anterior of the cell , accompanied by a smaller series of membranelles . The oral cavity is apical and funnel shaped , with a contractile vacuole discharging directly into it . When disturbed , the anterior of the cell can contract . The rest of the body is unciliated , except for a telotroch band circling the posterior in mobile species and stages . The larger order of peritrichia are the Sessilida . Most of these have modified posterior kinetosomes which secrete a contractile stalk . The unattached stage , called a telotroch , is mouthless . These are common in both freshwater and marine environments , and many live attached to aquatic plants and animals . They are either solitary or produce branched colonies . A few secrete a lorica . Vorticella is one of the best - known genera . Stalks may be as long as 2 mm , and in some cases where they are highly contractile can be extended up to 3 mm. The other peritrichia make up the order Mobilida . In these the posterior of the cell is enlarged and modified to form a complex holdfast , allowing the cell to temporarily attach to some host organism . Most live on the integument or gills of freshwater and marine invertebrates , but other hosts occur , including fish and even other ciliates , and other locations as well . Some can be pathenogenic in high populations . The peritrichs were first defined by Friedrich von Stein in 1859 . Initially they were considered spirotrichs , then treated as a separate category , before receiving their modern placement ., Subject: peritrich, Relation: taxon_rank, Options: (A) group (B) order (C) subclass
Output (English): subclass