Eisenia fetida

Eisenia fetida
Scientific classification
Kingdom:	Animalia
Phylum:	Annelida
Class:	Clitellata
Order:	Haplotaxida
Family:	Lumbricidae
Genus:	Eisenia
Species:	E. foetida
Binomial name
Eisenia foetida (Savigny, 1826) [1]

Eisenia fetida (older spelling: foetida), known under various common names such as redworm, brandling worm, tiger worm and red wiggler worm, red californian earth worm, is a species of earthworm adapted to decaying organic material. These worms thrive in rotting vegetation, compost, and manure; they are epigeal. They are rarely found in soil, instead preferring conditions that are inimical to some other worms. In this trait they resemble the Lumbricus rubellus.

Eisenia fetida worms are used for vermicomposting. They are native to Europe, but have been introduced (both intentionally and unintentionally) to every other continent except Antarctica, occasionally threatening native species.

Odor

When roughly handled, an eisenia fetida exudes a pungent liquid, thus the specific name foetida meaning foul-smelling. This is presumably an antipredator adaptation.

Subspecies

Eisenia fetida is closely related to Eisenia andrei, also referred to as E. foetida andrei.^[which?] The only simple way of distinguishing the two species is that E. foetida is lighter in colour. Molecular analyses have confirmed their identity as separate species and breeding experiments have shown that they do not produce hybrids.

Reproduction

As with other earthworm species, Eisenia fetida is hermaphroditic. However, two worms are still required for reproduction. The two worms join clitellums, the large orangeish bands which contain the worms' reproductive organs, and which are only visible during the reproduction process. The two worms exchange sperm. Both worms then secrete cocoons which contain several eggs each. These cocoons are lemon-shaped and are pale yellow at first, becoming more brownish as the worms inside become mature. These cocoons are clearly visible to the naked eye.

Relationship with humans

Eisenia fetida spill out of a compost bin after rising to the lid on a wet day.

They are widely sold by weight for use in vermiculture owing to their remarkable ability to process organic matter into fertile compost. They are also sold as bait though may produce an allergic reaction after direct contact with the skin for some individuals^[2].

References

1. ^ "Eisenia foetida". Fauna Europaea. 2004. http://www.faunaeur.org/full_results.php?id=178401. 
2. ^ Valero Santiago, A; Huguet Casals, J, Sanosa Valls, J, Malet Casajuana, A, García Calderón, PA (1989 Nov-Dec). "Angioedema, rhinitis and asthma provoked by fishing bait (Eisenia foetida).". Allergologia et immunopathologia 17 (6): 331-5. PMID 2483971.