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  3. Bootlace Worm

Ribbon worms · Heteronemertea · Lineidae

Bootlace Worm

Lineus longissimus

Not Evaluated

It has not yet been assessed against the IUCN criteria.

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The bootlace worm is a nemertean of the order Heteronemertea. It is one of the longest animals on Earth. Certain specimens found on the shore measure up to about 55 m when unwound. It is considered the longest animal in the world. It has a flaccid, fragile body of a brownish colour, with pale lines running along its length, and it is somewhat slimy. Its mucus is toxic.

Size

5 m – 30 m

Diet

Carnivore

Feeds mainly on other animals.

Social structure

Solitary

Lives and hunts alone, joining others only to breed.

Ocean
13countries22parks17dive sites

Fun facts

  • A specimen washed up on a Scottish beach in 1864 was measured at some fifty-five metres, which makes it the longest animal ever recorded, though its body stretches so much that the figure is disputed.
  • It hunts with a proboscis, separate from the gut, that it shoots out from its head and that wraps around or pierces the prey.
  • Its mucus contains powerful toxins, among them anabaseine, a compound that has been studied as a basis for neurological drugs and insecticides.
  • It is considered the longest animal in the world. Ordinary specimens measure between 5 and 15 metres, 30-metre ones are known, and there is a record of 55, longer than an Olympic swimming pool.
  • The record is disputed: it is extraordinarily elastic and reaches those lengths only fully stretched. Its width, by contrast, never exceeds a centimetre.
  • Its mucus is the most toxic animal compound found in Sweden. When irritated it releases large amounts of thick slime loaded with peptide neurotoxins.
  • Those toxins, named alpha-nemertides, block invertebrate sodium channels. The main one kills green crabs at a microgram per kilo, and cockroaches and varroa mites as well.
  • That is why they are being investigated as agricultural insecticides: they are functional relatives of the cone snails' toxins.
  • It hunts with an eversible proboscis that it shoots out to seize prey, the defining feature of the ribbon worm phylum.

Life cycle and biology

Skeleton type
Invertebrate - no rigid skeleton (hydrostatic skeleton)
Habitat and environment
Under stones and among algae in the intertidal and subtidal of the north-eastern Atlantic

Sources consulted: Wikipedia (es): Lineus longissimus

Where to find it

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Where to see it

Parks and dive sites where this species has been documented — showing 20 of 39.

Related species

Other species in the catalogue with the most in common with Bootlace Worm — same habitat, park, country, tags or family.

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Keep exploring

Based on what we already know about bootlace worm.

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The pins mark the parks and dive sites where its presence is documented.

See its range on the interactive map→
Wadden Sea National ParkDenmark
Wadden SeaGermany
Pembrokeshire CoastUnited Kingdom
NorthumberlandUnited Kingdom
Cíes IslandsSpain
Ria FormosaPortugal
KosterhavetSweden
UrdaibaiSpain
ArrábidaPortugal
MadeiraPortugal
Scapa FlowUnited Kingdom
Farne IslandsUnited Kingdom
Lofoten (orcas)Norway
SaltstraumenNorway
Berlengas IslandsPortugal
St AbbsUnited Kingdom
Malin HeadIreland
Strýtan (hydrothermal chimney)Iceland
Cíes IslandsSpain
SesimbraPortugal
See all 22 parks
See all 17 dive sites
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CountriesUnited Kingdom
ParksWadden Sea National ParkDenmark
TagsCarnivore
Carnivore
Solitary
Ocean
Worm

Europe12

Africa1

United Kingdom
Portugal
Ireland
Denmark
Germany
Norway
Belgium
Denmark
France
Germany
Iceland
Ireland
Netherlands
Norway
Portugal
Spain
Sweden
United Kingdom
Morocco