The bootlace worm (''Lineus longissimus'') is a species of ribbon worm and one of the longest known animals, with specimens up to long being reported. Its

mucus Mucus (, ) is a slippery aqueous secretion produced by, and covering, mucous membranes. It is typically produced from cells found in mucous glands, although it may also originate from mixed glands, which contain both Serous fluid, serous and muc ...

is highly toxic.

Taxonomy

The bootlace worm is in the phylum

Nemertea Nemertea is a phylum of animals also known as ribbon worms or proboscis worms, consisting of about 1300 known species. Most ribbon worms are very slim, usually only a few millimeters wide, although a few have relatively short but wide bodies. ...

or ribbon worms. It is the most common nemertean found along the

coast A coast (coastline, shoreline, seashore) is the land next to the sea or the line that forms the boundary between the land and the ocean or a lake. Coasts are influenced by the topography of the surrounding landscape and by aquatic erosion, su ...

s of

Britain Britain most often refers to: * Great Britain, a large island comprising the countries of England, Scotland and Wales * The United Kingdom of Great Britain and Northern Ireland, a sovereign state in Europe comprising Great Britain and the north-eas ...

Description

Bootlace worms may grow very long but are usually only in width. The body is brown with lighter (longitudinal) stripes. Its mucus contains a relatively strong

neurotoxin Neurotoxins are toxins that are destructive to nervous tissue, nerve tissue (causing neurotoxicity). Neurotoxins are an extensive class of exogenous chemical neurological insult (medical), insultsSpencer 2000 that can adversely affect function ...

which it uses as a defense against predators. When handled, it produces large amounts of thick mucus with a faint pungent smell, reminiscent of iron or sewage. This toxic mucus has been shown to kill

crab Crabs are decapod crustaceans of the infraorder Brachyura (meaning "short tailed" in Greek language, Greek), which typically have a very short projecting tail-like abdomen#Arthropoda, abdomen, usually hidden entirely under the Thorax (arthropo ...

s and

cockroach Cockroaches (or roaches) are insects belonging to the Order (biology), order Blattodea (Blattaria). About 30 cockroach species out of 4,600 are associated with human habitats. Some species are well-known Pest (organism), pests. Modern cockro ...

es, and could have applications as an agricultural

insecticide Insecticides are pesticides used to kill insects. They include ovicides and larvicides used against insect eggs and larvae, respectively. The major use of insecticides is in agriculture, but they are also used in home and garden settings, i ...

. In 1864,

William M'Intosh William Carmichael M'Intosh LLD (also spelt McIntosh; 10 October 1838, St Andrews – 1 April 1931, St Andrews) was a Scottish physician and marine zoologist. He served as president of the Ray Society, as vice-president of the Royal Societ ...

described a specimen that had washed ashore in the aftermath of a severe storm by

St Andrews St Andrews (; ; , pronounced ʰʲɪʎˈrˠiː.ɪɲ is a town on the east coast of Fife in Scotland, southeast of Dundee and northeast of Edinburgh. St Andrews had a recorded population of 16,800 , making it Fife's fourth-largest settleme ...

Scotland Scotland is a Countries of the United Kingdom, country that is part of the United Kingdom. It contains nearly one-third of the United Kingdom's land area, consisting of the northern part of the island of Great Britain and more than 790 adjac ...

, which was more than long, longer than the longest known

lion's mane jellyfish The lion's mane jellyfish (''Cyanea capillata'') is one of the Largest organisms#Cnidarians (Cnidaria), largest known species of jellyfish. Its range is confined to cold, boreal ecosystem, boreal waters of the Arctic Ocean, Arctic, northern Atla ...

, the animal which is often considered to be the longest in the world. However, records of extreme length should be taken with caution, because the bodies of nemerteans are flexible and can easily stretch to much more than their usual length. Like other nemerteans, ''Lineus longissimus'' feeds using its eversible

proboscis A proboscis () is an elongated appendage from the head of an animal, either a vertebrate or an invertebrate. In invertebrates, the term usually refers to tubular arthropod mouthparts, mouthparts used for feeding and sucking. In vertebrates, a pr ...

. As it is in the class

Anopla Anopla (for changes in taxonomy, see reference from 2019) has long been used as name for a Class (biology), class of marine worms of the phylum Nemertea, characterized by the absence of stylet (anatomy), stylets on the proboscis, the mouth being ...

, its proboscis is not armed with a barbed stylet. Instead, it has a cluster of sticky filaments at the end of its proboscis that it uses to immobilize prey.

Habitat

''Lineus longissimus'' can be found on Norway's and Britain's coasts, on the Danish east coast and also on Sweden's west coast.

References

External links

* * *
Lineus longissimus (Gunnerus, 1770) (accepted name)
Catalogue of Life: 30 April 2017 {{Taxonbar, from=Q134358 Marine fauna of Europe Lineidae Animals described in 1770 Taxa named by Johan Ernst Gunnerus