HOME

TheInfoList



OR:

''Lumbricus terrestris'' or the ''common earthworm'' is a large, reddish
worm Worms are many different distantly related bilateral animals that typically have a long cylindrical tube-like body, no limbs, and no eyes (though not always). Worms vary in size from microscopic to over in length for marine polychaete wor ...
species thought to be native to
Western Europe Western Europe is the western region of Europe. The region's countries and territories vary depending on context. The concept of "the West" appeared in Europe in juxtaposition to "the East" and originally applied to the ancient Mediterranean ...
, now widely distributed around the world (along with several other lumbricids). In some areas where it is an
introduced species An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived there ...
, some people consider it to be a significant pest for out-competing native worms. Through much of Europe, it is the largest naturally occurring 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 ...
, typically reaching 20 to 25 cm in length when extended.


Common names

Because it is widely known, ''L. terrestris'' goes under a variety of common names. In Britain, it is primarily called the common earthworm or lob worm (though the name is also applied to a marine
polychaete Polychaeta () is a paraphyletic class (biology), class of generally marine invertebrate, marine annelid worms, common name, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that ...
). In
North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
, the term nightcrawler (or vitalis) is also used. In Canada, it is also called the dew worm, or "Grandaddy Earthworm". In several
Germanic languages The Germanic languages are a branch of the Indo-European language family spoken natively by a population of about 515 million people mainly in Europe, North America, Oceania and Southern Africa. The most widely spoken Germanic language, Engli ...
, it is called variants of "rain worm", for example in
German German(s) may refer to: * Germany (of or related to) **Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Ger ...
''Gemeiner Regenwurm'' ("common rain worm") or in
Danish Danish may refer to: * Something of, from, or related to the country of Denmark People * A national or citizen of Denmark, also called a "Dane," see Demographics of Denmark * Culture of Denmark * Danish people or Danes, people with a Danish a ...
''Stor regnorm'' ("large rain worm"). In the rest of the world, many references are just to the scientific name, though with occasional reference to the above names. Although this is not the most abundant earthworm, even in its native range, it is a very conspicuous and familiar earthworm species in garden and agricultural soils of the temperate zone, and is frequently seen on the surface, unlike most other earthworms. It is also used as the example earthworm for millions of biology students around the world, even in areas where the species does not exist. However, 'earthworm' can be a source of confusion since, in most of the world, other species are more typical. For example, through much of the unirrigated temperate areas of the world, the "common earthworm" is actually ''
Aporrectodea ''Aporrectodea'' is a genus of earthworms in the family Lumbricidae. The genus includes some of the most common earthworms in the Palearctic realm and in agricultural soils across the temperate regions of the world.Pérez-Losada, M., et al. (2009 ...
'' (=''Allolobophora'') ''trapezoides'', which in those areas is a similar size and dark color to ''L. terrestris''.


Description

''Lumbricus terrestris'' is relatively large, pinkish to reddish-brown in colour, generally in length and about in diameter. It has around 120–170 segments, often 135–150. The body is cylindrical in the cross section, except for the broad, flattened posterior section. Head end dark brown to reddish brown lateral, dorsal pigmentation fading towards the back. The worm has a
hydrostatic skeleton A hydrostatic skeleton, or hydroskeleton, is a flexible skeleton supported by fluid pressure. Hydrostatic skeletons are common among simple invertebrate organisms. While more advanced organisms can be considered hydrostatic, they are sometimes refe ...
and moves by longitudinal and circular muscular contractions.
Setae 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 ...
– tiny hair-like projections – provide leverage against the surrounding soil. Surface movements on moist, flat terrain were reported at a speed of 20 m/h and, based on measurements of the length of the trail, nocturnal activity away from the burrow was estimated at up to 19 m during a single surface foray. Such movement is apparent during and after heavy rainfall and usually happens when people become aware of relatively large numbers of earthworms in, for example, urban ecosystems. This form of activity is often considered a way to escape floods and waterlogged burrows. However, this cannot be the case since ''L. terrestris'', like other earthworms, can live in oxygenated water for long periods of time, stretching to weeks. Under less severe environmental conditions where air temperature and moisture are sufficient, the worm often moves around on the surface. This may be driven by resource availability or the desire to avoid mating with close relatives.


Ecology

''Lumbricus terrestris'' is a deep-burrowing anecic earthworm, that is, it builds deep vertical burrows and surfaces to feed, as opposed to burrowing through the soil for its food as endogeic species. It removes litter from the soil surface, pulling it down into the mineral layer, and deposit casts of mixed organic and mineral material on the soil surface. It lives in semi-permanent burrows and can reside in or escape to deeper soil layers. Its activity is limited by temperature and humidity. High soil and night air temperatures inhibit activity, as do low night moisture and dry soil. During such times, particularly in the summer, the worms will retreat to the deepest parts of their burrows. Winter temperatures can also reduce activity, while activity in maritime climates can continue through winter. ''Lumbricus terrestris'' can strongly influence soil fungi, creating distinctive micro-habitats called middens, which strongly affect the spatial distribution of plant litter and litter-dwelling animals on the soil surface. In the soil system, ''L. terrestris'' worm casts produce have a relationship with plants which can be seen in such scenarios such as in plant propagation from seed or clone. Worm casts initiate root development, root biomass, and in effect, increase root percentage as opposed to the soil and soil systems without worm casts. In parts of
Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...
, notably the
Atlantic The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe an ...
fringe of northwestern Europe, it is now locally
endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inva ...
due to predation by the
New Zealand flatworm The New Zealand flatworm (''Arthurdendyus triangulatus'') is a large land flatworm native to New Zealand. It can vary from 5 mm in length when hatched to approximately in mature adults. The New Zealand flatworm is considered an invasive s ...
(''Arthurdendyus triangulatus'') and the Australian flatworm (''Australoplana sanguinea''), two predatory
flatworms The flatworms, flat worms, Platyhelminthes, or platyhelminths (from the Greek πλατύ, ''platy'', meaning "flat" and ἕλμινς (root: ἑλμινθ-), ''helminth-'', meaning "worm") are a phylum of relatively simple bilaterian, unsegment ...
accidentally introduced from
New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
and
Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
. These predators are very efficient earthworm eaters, being able to survive for lengthy periods with no food, so still persist even when their prey has dropped to unsustainably low populations. In some areas, this is having a seriously adverse effect on the
soil Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former te ...
structure and quality. The soil aeration and organic material mixing previously done by the earthworms has ceased in some areas.


Diet

''Lumbricus terrestris'' is a
detritivore Detritivores (also known as detrivores, detritophages, detritus feeders, or detritus eaters) are heterotrophs that obtain nutrients by consuming detritus (decomposing plant and animal parts as well as feces). There are many kinds of invertebrates, ...
that eats mainly dead leaves on the soil floor and A-horizon mineral soil. Preference is associated with high concentrations of
calcium Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to ...
and likely
nitrogen Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...
. As a result,
basswood ''Tilia americana'' is a species of tree in the family Malvaceae, native to eastern North America, from southeast Manitoba east to New Brunswick, southwest to northeast Oklahoma, southeast to South Carolina, and west along the Niobrara River to ...
,
ash Ash or ashes are the solid remnants of fires. Specifically, ''ash'' refers to all non-aqueous, non- gaseous residues that remain after something burns. In analytical chemistry, to analyse the mineral and metal content of chemical samples, ash ...
and
aspen Aspen is a common name for certain tree species; some, but not all, are classified by botanists in the section ''Populus'', of the ''Populus'' genus. Species These species are called aspens: *'' Populus adenopoda'' – Chinese aspen (China ...
are most favored, followed by
sugar maple ''Acer saccharum'', the sugar maple, is a species of flowering plant in the soapberry and lychee family Sapindaceae. It is native to the hardwood forests of eastern Canada and eastern United States. Sugar maple is best known for being the prima ...
and
maple ''Acer'' () is a genus of trees and shrubs commonly known as maples. The genus is placed in the family Sapindaceae.Stevens, P. F. (2001 onwards). Angiosperm Phylogeny Website. Version 9, June 2008 nd more or less continuously updated since http ...
varieties.
Oak An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably ''L ...
is less palatable due to its low concentration of calcium, but will be eaten if no higher calcium leaves are available. While they generally feed on plant material, they have been observed feeding on dead insects, soil micro-organisms, and feces.


Reproduction

''Lumbricus terrestris'' is an obligatorily biparental, simultaneous
hermaphrodite In reproductive biology, a hermaphrodite () is an organism that has both kinds of reproductive organs and can produce both gametes associated with male and female sexes. Many Taxonomy (biology), taxonomic groups of animals (mostly invertebrate ...
worm, that reproduces sexually with individuals mutually exchanging
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 ...
. Copulation occurs on the soil surface, but partners remain anchored in their burrow and mating is preceded by repeated mutual burrow visits between neighbors. Additionally, when mates separate, one of them can be pulled out of its burrow. Mating frequency is relatively high (once every 7–11 days). The relative size of the mate, the distance from the presumed mates, the chance of being dragged to the surface, and the size-related fecundity all tend to play key roles in the mating behavior of the nightcrawler. Sperm is stored for as long as 8 months, and mated individuals produce cocoons for up to 12 months after the mating. Fertilization takes place in the cocoon and the cocoon is deposited in a small chamber in the soil adjacent to the parental burrow. After a few weeks, young worms emerge and begin to feed in the soil. In the early juvenile phase, the worms do not develop the vertical burrows typical of adults. Adulthood is likely to require a minimum of one year of development, with reproductive maturity reached in the second year. The natural lifespan of ''L. terrestris'' is unknown, though individuals have lived for six years in captivity.


As an invasive species in North America

''Lumbricus terrestris'' is considered invasive in the north central United States. It does not do well in tilled fields because of pesticide exposure, physical injuries from farm equipment and a lack of nutrients. It thrives in fence rows and woodlots and can lead to reductions in native herbaceous and tree regrowth.


References


External links

* *


Further reading

* {{Authority control Lumbricidae Animals described in 1758 Taxa named by Carl Linnaeus