Eisenia fetida
Encyclopedia
Eisenia fetida 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.
, also referred to as E. foetida andrei. 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.
species, Eisenia fetida is hermaphroditic. However, two worms are still required for reproduction. The two worms join clitellum
s, 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.
. They are also sold as bait
though may produce an allergic reaction after direct contact with the skin for some individuals.
Earthworm
Earthworm is the common name for the largest members of Oligochaeta in the phylum Annelida. In classical systems they were placed in the order Opisthopora, on the basis of the male pores opening posterior to the female pores, even though the internal male segments are anterior to the female...
adapted to decaying
Decomposition
Decomposition is the process by which organic material is broken down into simpler forms of matter. The process is essential for recycling the finite matter that occupies physical space in the biome. Bodies of living organisms begin to decompose shortly after death...
organic material. These worms thrive in rotting vegetation
Vegetation
Vegetation is a general term for the plant life of a region; it refers to the ground cover provided by plants. It is a general term, without specific reference to particular taxa, life forms, structure, spatial extent, or any other specific botanical or geographic characteristics. It is broader...
, compost
Compost
Compost is organic matter that has been decomposed and recycled as a fertilizer and soil amendment. Compost is a key ingredient in organic farming. At its most essential, the process of composting requires simply piling up waste outdoors and waiting for the materials to break down from anywhere...
, and manure
Manure
Manure is organic matter used as organic fertilizer in agriculture. Manures contribute to the fertility of the soil by adding organic matter and nutrients, such as nitrogen, that are trapped by bacteria in the soil...
; they are epigeal
Epigeal
Epigeal, epigean, epigeic and epigeous are biological terms describing an organism's activity above the soil surface.In botany, a seed is described as epigeal when the cotyledons of the germinating seed expand, throw off the seed shell and become photosynthetic above the ground...
. They are rarely found in soil, instead preferring conditions that are inimical to some other worms. In this trait they resemble the Lumbricus rubellus
Lumbricus rubellus
Lumbricus rubellus is a species of earthworm that is related to Lumbricus terrestris. It is usually reddish brown or reddish violet, iridescent dorsally, and pale yellow ventrally...
.
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 andreiEisenia andrei
Eisenia andrei is a close relative of the 'brandling' or 'tiger' worm, Eisenia fetida. Like its sibling species, it is epigeic, i.e. it prefers to live in compost or leaf litter rather than mineral soils....
, also referred to as E. foetida andrei. 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 earthwormEarthworm
Earthworm is the common name for the largest members of Oligochaeta in the phylum Annelida. In classical systems they were placed in the order Opisthopora, on the basis of the male pores opening posterior to the female pores, even though the internal male segments are anterior to the female...
species, Eisenia fetida is hermaphroditic. However, two worms are still required for reproduction. The two worms join clitellum
Clitellum
The clitellum is a thickened glandular section of the body wall in earthworms and leeches, that secretes a viscid sac in which the eggs are deposited...
s, the large orangeish bands which contain the worms' reproductive organs, and which are only visible during the reproduction process. The two worms exchange sperm
Sperm
The term sperm is derived from the Greek word sperma and refers to the male reproductive cells. In the types of sexual reproduction known as anisogamy and oogamy, there is a marked difference in the size of the gametes with the smaller one being termed the "male" or sperm cell...
. 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
They are widely sold by weight for use in vermiculture owing to their remarkable ability to process organic matter into fertile compostCompost
Compost is organic matter that has been decomposed and recycled as a fertilizer and soil amendment. Compost is a key ingredient in organic farming. At its most essential, the process of composting requires simply piling up waste outdoors and waiting for the materials to break down from anywhere...
. They are also sold as bait
Bait (luring substance)
Bait is any substance used to attract prey, e.g. in a mousetrap.-In Australia:Baiting in Australia refers to specific campaigns to control foxes, wild dogs and dingos by poisoning in areas where they are a problem...
though may produce an allergic reaction after direct contact with the skin for some individuals.