''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 contrast ...

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. T ...

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 charac ...

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 ...

, 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 Soil fertility, fertility of soil by adding organic ma ...

. 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 ...

, rarely found in soil. In this trait, they resemble '' Lumbricus rubellus''. 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. ...

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 cont ...

. ''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, ...

ic fluid: cells called coelomocytes secrete a protein called lysenin, which is a pore-forming toxin (PFT), which is able to permeabilize and lyse 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

''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 hybrids. 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

As with other

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 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, ...

. 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