Eisenia fetida, known under various common names such as manure worm,
The worm is reddish-brown in color, has small rings around its body, and has a yellowish tail.
E. fetida worms are native to Europe, but have been introduced (both intentionally and unintentionally) to every other continent except Antarctica.
E. fetida also possesses a unique natural defense system in its fluid; cells called coelomocytes secrete a protein called lysenin, which is a pore-forming toxin, which is able to permeabilize and lysis invading cells. It is best at targeting foreign cells whose membranes contain significant amounts of sphingomyelin. (Lysenin is also toxic to organisms lacking sphingomyelin in their cell walls, including Bacillus megaterium, though the pathway is not understood).
Uses
E. fetida is used for
Vermicompost of both domestic and industrial organic waste.
Vermicomposting septic systems have been used for decades and allow for decentralized on-site processing of blackwater using
Eisenia fetida.
Tiger worms are also being tested for use in a flushless toilet, currently being trialled in India, Uganda and Myanmar.
Moreover, red worm is widely used in fishing, being one of the most ideal baits for tench, bream, and roach.
Odor
When roughly handled a redworm exudes a
pungent liquid, thus the specific name
fetida meaning "". This is presumably an antipredator adaptation.
Related species
E. fetida is closely related to
Eisenia andrei, also referred to as
E. f. andrei. The only simple way of distinguishing the two species is that
E. fetida is sometimes lighter in colour, however identification by morphology is not reliable.
Molecular analyses have confirmed their identity as separate species, and breeding experiments have shown that they do produce hybrids.
The mitochondrial genetic characteristics of the Irish population of E. fetida could be the result of reproductive isolation, so suggests that this sample may constitute an unrecognized species or subspecies of E. fetida.
Reproduction
As with other
earthworm species,
E. fetida is
hermaphroditic, and uniparental reproduction is possible, even if usually the reproduction is between copulating individuals.
The two worms join
clitella, the large, lighter-colored bands which contain the worms' reproductive organs, and which are only prominent 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. At 25°C,
E. fetida hatches from its cocoon in about 3 weeks.
DNA repair
Ionizing radiation induces DNA strand breaks and oxidized DNA bases in both
spermatogenesis and somatic cells of
E. fetida, and also induces the
DNA repair of these damages.
Lifespan
The lifespan of
E. fetida under controlled conditions varies between one and five years.
Habitat
The ideal habitat of Eisenia fetida includes organic matter that they can feast on. Usually they live just beneath the surface to avoid light. The temperature of the mixture in which they reside should be between 40°F to 90°F. In the summer, they will actively go deeper than 6 inches to find cooler areas as they don't prefer heat. The cocoons that they form can handle even harsher temperatures.
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