The bootlace worm (''Lineus longissimus'') is a species of

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

and one of the longest known animals, with specimens up to long being reported, although this has not been confirmed. 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 and mucous cells. It ...

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 1300 known species. Most ribbon worms are very slim, usually only a few millimeters wide, although a few have relatively short but wide bodies. Many h ...

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

coast The coast, also known as the coastline or seashore, is defined as the area where land meets the ocean, or as a line that forms the boundary between the land and the coastline. The Earth has around of coastline. Coasts are important zones in n ...

s of

Britain Britain most often refers to: * The United Kingdom, a sovereign state in Europe comprising the island of Great Britain, the north-eastern part of the island of Ireland and many smaller islands * Great Britain, the largest island in the United King ...

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 nerve tissue (causing neurotoxicity). Neurotoxins are an extensive class of exogenous chemical neurological insultsSpencer 2000 that can adversely affect function in both developing and mature nerv ...

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

crabs Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen) ( el, βραχύς , translit=brachys = short, / = tail), usually hidden entirely under the thorax. They live in all the ...

and

cockroaches Cockroaches (or roaches) are a paraphyletic group of insects belonging to Blattodea, containing all members of the group except termites. About 30 cockroach species out of 4,600 are associated with human habitats. Some species are well-known ...

, and could have applications as an agricultural

insecticide Insecticides are substances used to kill insects. They include ovicides and larvicides used against insect eggs and larvae, respectively. Insecticides are used in agriculture, medicine, industry and by consumers. Insecticides are claimed t ...

. 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 Socie ...

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

St Andrews St Andrews ( la, S. Andrea(s); sco, Saunt Aundraes; gd, Cill Rìmhinn) 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 fourt ...

Scotland Scotland (, ) is a country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a border with England to the southeast and is otherwise surrounded by the Atlantic Ocean to ...

, which was more than long,Gerald L. Wood ''Animal Facts and Feats: A Guinness Record of the Animal Kingdom'', pg 334. longer than the longest known Lion's mane jellyfish, 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 mouthparts used for feeding and sucking. In vertebrates, a proboscis is an elong ...

. 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 of marine worms of the phylum Nemertea, characterized by the absence of stylets on the proboscis, the mouth being below or behind the brain, and by ...

, 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, 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