Chytridiomycota
From Wikipedia, the free encyclopedia
| Chytridiomycota Fossil range: Devonian - Recent |
||||
|---|---|---|---|---|
 |
||||
| Scientific classification | ||||
|
||||
| Type species | ||||
| Chytridium spp. A. Braun, 1851 |
||||
| Classes | ||||
Chytridiomycota (pronounced /kɪˈtrɪdi.ɵmaɪˈkoʊtə/, ki-TRID-ee-o-mye-KOH-tə) or chytrids (sg. pronounced /ˈkɪtrɪd/, KIT-rid) is a division of the Fungi kingdom. The name is derived from the Greek chytridion, meaning "little pot", describing the structure containing unreleased spores. In older classifications, chytrids (except the recently established order Spizellomycetales) were placed in the Class Phycomycetes under the subdivision Myxomycophyta of the Kingdom Fungi. Also, in an older and more restricted sense (not used here), the term "chytrids" referred just to those fungi in the order Chytridiales.
The chytrids are the most primitive of the fungi and are mostly saprobic (degrading chitin and keratin). The thalli are coenocytic and usually form no true mycelium (having rhizoids instead). Some species are unicellular. Like other fungi, the cell wall in chytrids is composed of chitin.
Many chytrids are aquatic (mostly found in fresh water). There are approximately 1,000 chytrid species, in 127 genera, distributed among 5 orders.
Contents |
[edit] Reproduction
Both zoospores and gametes of the chytrids are mobile by their flagella, one whiplash per individual.
An example of a Chytrid species is the water mold - Allomyces sap, it is a saprotroph found in water or wet soil. The species has an interesting life cycle. The thallus (body) is attached by rhizoids, and has an erect trunk on which reproductive organs are formed at the end of branches. The life cycle has the ability to change from haploid and diploid generations. The haploid thallus forms male and female gametangia from which flagellated gametes are released and merge to form a Zygote. Gametes and female gametangia attract the opposite sex by producing pheromones. The germinated zygote produces a diploid thallus with two sorts of sporangia; thin-walled zoosporangia which release diploid zoospores resulting in a diploid thalli and thick-walled sporangia which after meiosis release haploid zoospores which form haploid thalli.
[edit] Disease of Amphibians
 |
It has been suggested that this article or section be merged with Batrachochytrium dendrobatidis. (Discuss) |
One symptom of chytrid fungal infection in amphibians is discolored skin, which may slough or peel off. This can vary from obvious peeling of skin (particularly on the feet), to a roughness of the frog's skin that is difficult to see. The frog may sit out in the open, instead of protecting itself by hiding. It may be sluggish, and have no appetite, and have its legs spread slightly away from itself, rather than keeping them tucked close to its body. In more extreme cases, the frog's body will be rigid, and its back legs will trail behind it. [2]
[edit] Treatment for Frogs
|
|
It has been suggested that this article or section be merged with Batrachochytrium dendrobatidis. (Discuss) |
Despite rumors of Chloramphenicol as a possible cure for this fatal frog disease, repeated trials have unfortunately shown the compound to be no more effective at conferring resistance than previously-known antifungal agents. [3]
[edit] As a parasite
The chytrid Batrachochytrium dendrobatidis is responsible for a recently discovered disease of amphibians, chytridiomycosis. Discovered in 1998 in Australia and Panama this disease is known to kill amphibians in large numbers, and has been suggested as a principal cause for the worldwide amphibian decline. The actual process leading to mortality is, however, unknown.
Chytrids may also infect plant species; in particular, maize-attacking and alfalfa-attacking species have been described. Synchytrium endobioticum is an important potato pathogen.
[edit] Fossil record
The earliest fossils of chytrids are from the Scottish Rhynie chert, a Devonian-age locality with anatomical preservation of plants and fungi. Among the microfossils are chytrids preserved as parasites on rhyniophytes. These fossils closely resemble the genus Allomyces.[4]
[edit] References
- ^ Hibbett, D.S., et al. (March 2007). "A higher level phylogenetic classification of the Fungi". Mycol. Res. 111 (5): 509–547. doi:.
- ^ http://www.environment.nsw.gov.au/plantsanimals/FrogChytridFungus.htm
- ^ http://news.bbc.co.uk/1/hi/sci/tech/7067613.stm
- ^ Taylor, T.N.; W. Remy, & H. Hass. (1994). "Allomyces in the Devonian". Nature 367: 601. doi:.
[edit] External links
 |
Wikimedia Commons has media related to: Chytridiomycota |
- Chytrid Fungi Online: by the University of Alabama
- Introduction to the Chytridiomycota: at the UC Museum of Paleontology
- Impact of chytrid fungus on frogs (Foundation for National Parks & Wildlife)
- 'Amphibian Ark' aims to save frogs from fungus
- The Aquarium Wiki Encyclopaedia on Chytrid Fungus and how it impacts amphibians kept as domestic pets.
- NIH
- MeSH Chytridiomycota
|
|||||||||||||||||||||||||||||||||||||||||||||
