Encyclopedia > Hymenostomatida

  Article Content

Hymenostomatida

Hymenostomatida
Scientific classification
Kingdom:Protista
Phylum:Ciliophora
Class:Oligohymenophorea
Order:Hymenostomatida
Typical families
Suborder Tetrahymenina
    Curimostomatidae
    Tetrahymenidae
    Turaniellidae
    Glaucomidae
Suborder Ophryoglenina
    Ichthyopthiriidae
    Ophryoglenidae

The Hymenostomatida are an order of ciliate protozoa, included in the class Oligohymenophorea. Most are free-living in freshwater, such as the commonly studied genus Tetrahymena, but some are parasitic on fish or aquatic invertebrates, generally with a complicated life-cycle. Among these is the important species Ichthyopthirius multifiis[?], a common cause of death in aquaria and fish farms.

As is typical for the class, the body cilia are mostly uniform, sometimes with a few long caudal cilia, and arise from monokinetids or from dikinetids at the anterior. The oral cilia are in general distincly tetrahymenal, with three membranelles and a paroral membrane, which corresponds only to the middle segment of the tripartite membranes found in certain scuticociliates[?]. Mouth formation during cell division usually begins next to a postoral kinety.

The Hymenostomes were first defined by Delage & Hérouard in 1896. Intially the scuticociliates and peniculids were included, then later treated as separate orders of a subclass Hymenostomatia, to which the astomes[?] are sometimes added. More recently each of these groups tends to be treated as a separate subclass.



All Wikipedia text is available under the terms of the GNU Free Documentation License

 
  Search Encyclopedia

Search over one million articles, find something about almost anything!
 
 
  
  Featured Article
Saxony-Anhalt

... Land[?] Kö ...