Biodiversity & Conservation

Bootlace worm - Lineus longissimus

Lineus longissimus

Image David Fenwick - The ribbonworm Lineus longissimus partially exposed in a tide pool. Image width ca XX cm
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Distribution map

Lineus longissimus recorded (dark blue bullet) and expected (light blue bullet) distribution in Britain and Ireland (see below)

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Lineus longissimus is not listed under any importance categories.

Taxonomy icon Taxonomy Taxon English term
Phylum Nemertina Ribbon worms
Class Anopla
Authority (Gunnerus, 1770)
Recent synonyms None
Map icon Recorded Distribution in Britain and Ireland Most likely present all around Britain and Ireland, except perhaps eastern Scotland and England.
Habitat information icon Habitat information Lineus longissimus is found on the lower shore coiled in writhing knots beneath boulders and on muddy sand. This species can often be found in rockpools entangled amongst Laminaria holdfasts or in rock fissures. In deeper sub-littoral areas, it occurs on muddy, sandy, stony or shelly substrata.
Text page icon Description Lineus longissimus is an unsegmented, elongated ribbon worm. Young specimens range from dark olive brown to chocolate brown whereas adults are blackish brown to black. Epidermal cilia give the body a purplish irridescence. This species is the longest nemertean known. It is usually 5-15 m in length but can be over 30 m, usually 5 mm in width. The body is often streaked with pale longitudinal lines, especially on the anterior dorsal surface. The rectangular head has deep slits and ends in a pale colour tip. A row of up to 20 deep set reddish-brown or black eyes may be present either side of the snout. Pink or red cerebral ganglia may be seen through the epidermis.
Identifying features
  • Ventral surface may be same colour or paler than dorsal.
  • Body may be streaked with pale longitudinal lines especially on anterior dorsal surface.
  • Rectangular head with pale colour tip.
  • 10-20 deep set reddish brown or black eyes in a row either side of snout, which may be obscured by dark body colour.
  • Body unsegmented and ciliated, giving purplish irridescence.
Additional information icon Additional information Lineus longissimus is the most commonly recorded nemertean in Britain. When handled, the animal produces large amounts of thick mucus with a faint pungent smell.

This review can be cited as follows:

Judith Oakley 2005. Lineus longissimus. Bootlace worm. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 09/02/2010]. Available from: <http://www.marlin.ac.uk/speciesinformation.php?speciesID=3693>