Lumbricus terrestris
Encyclopedia
Lumbricus terrestris is a large reddish worm
Worm
The term worm refers to an obsolete taxon used by Carolus Linnaeus and Jean-Baptiste Lamarck for all non-arthropod invertebrate animals, and stems from the Old English word wyrm. Currently it is used to describe many different distantly-related animals that typically have a long cylindrical...

 native to Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

, but now also widely distributed elsewhere around the world (along with several other lumbricid
Lumbricidae
The Lumbricidae is a family of earthworms which includes most of the earthworm species well known to Europeans. About 33 lumbricid species have become naturalized around the world, but the bulk of the species are in Holarctic: from Canada and the United States The Lumbricidae is a family of...

s) due to human introductions. In some areas where it has been introduced, some people consider it to be a serious pest species since it is out-competing native worms.

Through much of Europe it is the largest naturally occurring species of earthworm
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...

, typically reaching 20 - 25 cm in length when extended (though in parts of southern Europe there are native species which are much larger). It has an unusual habit of copulating on the surface at night, which makes it more visible than most other earthworms.

Common names

Because it is widely known, Lumbricus terrestris goes under a variety of common names. In Britain, it is primarily called the Common Earthworm also Lob Worm (though that name is also applied to a marine polychaete
Polychaete
The Polychaeta or polychaetes are a class of annelid worms, generally marine. Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are made of chitin. Indeed, polychaetes are sometimes referred to as bristle worms. More than 10,000...

). In North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

, the term Nightcrawler (or Vitalis) is also used. In Canada, it is also called the Dew Worm. In the rest of the world, most 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 (=Allolobophora) trapezoides, which in those areas is a similar size and dark color to Lumbricus terrestris.

Biology

Lumbricus terrestris is an anecic worm. That is, it forms temporary deep burrows and comes to the surface to feed, as opposed to burrowing through the soil for its food as most other earthworms do. An unusual habit of this species is to pull leaves into the mouth of its burrow where they partially decay before being eaten. While they generally feed on plant material, they have been observed feeding on dead insects and feces.

The potential life span of Lumbricus terrestris is unknown, though it has lived up to the age of 6 years in captivity. The most widely accepted approximation is around 4-8 years in the wild.

In parts of Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

, notably the Atlantic fringe of northwestern Europe, it is now locally endangered
Conservation status
The conservation status of a group of organisms indicates whether the group is still extant and how likely the group is to become extinct in the near future...

 due to predation by the New Zealand Flatworm
New Zealand flatworm
The New Zealand flatworm is a large flatworm native to New Zealand. It can vary from 5 mm in length when hatched to approximately in mature adults. The ventral surface of the flatworm is a pale buff colour while the dorsal surface is dark brown...

 (Arthurdendyus triangulatus) and the Australian Flatworm (Australoplana sanguinea), two predatory flatworms accidentally introduced from New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

 and Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

. These predators are very efficient earthworm eaters, being able to survive for lengthy periods with no food, so therefore still persisting even when their prey has dropped to unsustainably low populations. In some areas, this is having a seriously adverse effect on the soil
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...

structure and quality. The soil aeration and organic material mixing previously done by the earthworms has ceased in some areas.

As an invasive species in North America

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

External links

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