''Eisenia fetida'', known under various
common names
In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often contra ...
such as manure worm, redworm, brandling worm, panfish worm, trout worm, tiger worm, red wiggler worm, etc., is a species of
earthworm
An earthworm is a terrestrial invertebrate that belongs to the phylum Annelida. They exhibit a tube-within-a-tube body plan; they are externally segmented with corresponding internal segmentation; and they usually have setae on all segments. Th ...
adapted to
decaying organic material. These worms thrive in rotting
vegetation
Vegetation is an assemblage of plant species and the ground cover they provide. It is a general term, without specific reference to particular taxa, life forms, structure, spatial extent, or any other specific botanical or geographic character ...
,
compost
Compost is a mixture of ingredients used as plant fertilizer and to improve soil's physical, chemical and biological properties. It is commonly prepared by decomposing plant, food waste, recycling organic materials and manure. The resulting m ...
, and
manure
Manure is organic matter that is used as organic fertilizer in agriculture. Most manure consists of animal feces; other sources include compost and green manure. Manures contribute to the fertility of soil by adding organic matter and nutri ...
. They are
epigean
Epigeal, epigean, epigeic and epigeous are biological terms describing an organism's activity above the soil surface.
In botany, a seed is described as showing epigeal germination when the cotyledons of the germinating seed expand, throw off th ...
, rarely found in soil. In this trait, they resemble ''
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. They are usually about to in length, with around 95– ...
''.
Red wigglers are reddish-brown in color, have small rings around their body and have a yellowish tail. They have groups of bristles (called
seta
In biology, setae (singular seta ; from the Latin word for "bristle") are any of a number of different bristle- or hair-like structures on living organisms.
Animal setae
Protostomes
Annelid setae are stiff bristles present on the body. Th ...
e) on each segment that move in and out to grip nearby surfaces as the worms stretch and contract their muscles to push themselves forward or backward.
''Eisenia fetida'' worms are native to Europe, but have been introduced (both intentionally and unintentionally) to every other continent except
Antarctica
Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest contine ...
.
''Eisenia fetida'' also possess a unique natural defense system in their
coelom
The coelom (or celom) is the main body cavity in most animals and is positioned inside the body to surround and contain the digestive tract and other organs. In some animals, it is lined with mesothelium. In other animals, such as molluscs, it r ...
ic fluid: cells called coelomocytes secrete a protein called
lysenin, which is a
pore-forming toxin
Pore-forming proteins (PFTs, also known as pore-forming toxins) are usually produced by bacteria, and include a number of protein exotoxins but may also be produced by other organisms such as apple snails that produce perivitellin-2 or earthwor ...
(PFT), which is able to permeabilize and
lyse Lyse may refer to:
* Lyse Abbey, a former Cistercian abbey in Norway
* Lyse, an alternative name of Lysebotn, Norway
* Lyse Energi, a Norwegian power company
* Łyse, Masovian Voivodeship, a village in east-central Poland
* Łyse, Podlaskie Voivode ...
invading cells. It is best at targeting foreign cells whose membranes contain significant amounts of
sphingomyelin
Sphingomyelin (SPH, ˌsfɪŋɡoˈmaɪəlɪn) is a type of sphingolipid found in animal cell membranes, especially in the membranous myelin sheath that surrounds some nerve cell axons. It usually consists of phosphocholine and ceramide, or a ethano ...
. (Lysenin is also toxic to organisms lacking sphingomyelin in their cell walls, including ''
Bacillus megaterium
''Bacillus megaterium'' is a rod-like, Gram-positive, mainly aerobic spore forming bacterium found in widely diverse habitats.De Vos, P. ''et al.'' Bergey's Manual of Systematic Bacteriology: Volume 3: The Firmicutes. ''Springer'' (2009) It has ...
'', though the pathway is not understood).
Uses
''Eisenia fetida'' are used for
vermicomposting
Vermicompost (vermi-compost) is the product of the decomposition process using various species of worms, usually red wigglers, white worms, and other earthworms, to create a mixture of decomposing vegetable or food waste, bedding materials, and ...
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.
Odor
When roughly handled, a redworm exudes a
pungent
Pungency () refers to the taste of food commonly referred to as spiciness, hotness or heat, found in foods such as chili peppers. Highly pungent tastes may be experienced as unpleasant. The term piquancy () is sometimes applied to foods with a l ...
liquid, thus the specific name ''fetida'' meaning "
foul-smelling". This is presumably an
antipredator adaptation
Anti-predator adaptations are mechanisms developed through evolution that assist prey organisms in their constant struggle against predators. Throughout the animal kingdom, adaptations have evolved for every stage of this struggle, namely by avo ...
.
Related species
''Eisenia fetida'' is closely related to ''
E. 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. Molecular analyses have confirmed their identity as separate species, and breeding experiments have shown that they do produce
hybrid
Hybrid may refer to:
Science
* Hybrid (biology), an offspring resulting from cross-breeding
** Hybrid grape, grape varieties produced by cross-breeding two ''Vitis'' species
** Hybridity, the property of a hybrid plant which is a union of two dif ...
s.
The mitochondrial genetic characteristics of the Irish population of ''E. fetida'' could be the result of reproductive isolation and so suggests that this sample may constitute an unrecognized species or subspecies of ''E. fetida''.
Reproduction
![Redwiggler-copulation-compost](https://upload.wikimedia.org/wikipedia/commons/3/30/Redwiggler-copulation-compost.jpg)
As with other
earthworm
An earthworm is a terrestrial invertebrate that belongs to the phylum Annelida. They exhibit a tube-within-a-tube body plan; they are externally segmented with corresponding internal segmentation; and they usually have setae on all segments. Th ...
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 clitellum is a thickened glandular and non-segmented section of the body wall near the head in earthworms and leeches, that secretes a viscid sac in which eggs are stored. It is located near the anterior end of the body, between the fourteenth ...
, 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
Sperm is the male reproductive cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm with a tail known as a flagellum, whi ...
. 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.
Life expectancy
The life expectancy of ''Eisenia fetida'' under controlled conditions varies, according to different authors, between one and five years.
References
External links
"Identify Tiger Worm"
{{Taxonbar, from=Q1501422
Lumbricidae
Animals described in 1826
Coprophagous animals
Composting
Organic gardening
Taxa named by Marie Jules César Savigny