Caenorhabditis | |
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Caenorhabditis elegans | |
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Nematoda |
Class: | Secernentea |
Order: | Rhabditida |
Family: | Rhabditidae |
Genus: |
Caenorhabditis (Osche, 1952) Dougherty, 1955 |
Synonyms | |
Rhabditis (Caenorhabditis) Osche, 1952 |
Rhabditis (Caenorhabditis) Osche, 1952
Caenorhabditis is a genus of nematodes which live in bacteria-rich environments like compost piles, decaying dead animals and rotting fruit. The name comes from Greek: caeno- (καινός (caenos) = new, recent); rhabditis = rod-like (ῥάβδος (rhabdos) = rod, wand). In 1900, Maupas initially named the species Rhabditides elegans, Osche placed it in the subgenus Caenorhabditis in 1952, and in 1955, Dougherty raised it to the status of genus.
The Caenorhabditis genus contains the noted model organism Caenorhabditis elegans and several other species for which a genome sequence is either available or currently being determined. The two most-studied species in this genus (C. elegans and C. briggsae) are both androdioecious (they have male and hermaphrodite sexes) whereas most other species are gonochoristic (they have male and female sexes).
C. elegans is the type species of the genus.
Caenorhabditis occupy various nutrient and bacteria rich environments. They do not form self-sustaining populations in soil, as it lacks enough organic matter. Juvenile worms and also dauer larvae can be transported by invertebrates including millipedes, insects, isopods, and gastropods. Some species also appear to be associated with vertebrates including zebu cattle, although the nature of this association is not clear. The species can be classified as 'phoretic' or 'necromenic' based on their relationships to their invertebrate hosts. A phoretic worm rides on the host until it finds a favorable environment, and then leaves. A necromenic worm waits for the host to die, and lives on the bacteria which thrive in the dead animal. Many species are capable of both phoretic and necromenic lifestyles.