Marine Species Identification Portal : Lineus sanguineus

(Rathke, 1799)

Description:
Somewhat similar to Lineus ruber in appearance, Lineus sanguineus is up to about 10-20 cm in length but possesses a much more slender body. On the head, the 4-6 eyes on each side are rather further back than in Lineus ruber and more regularly arranged (L. sanguineus-head). The colour varies from a bright reddish-brown to a dull mid-brown, frequently the posterior and ventral regions appearing paler. The species is readily distinguished from Lineus ruber by its behaviour when disturbed, contracting in a tight coil. The species possesses well-developed powers of regeneration. Dermis without distinct connective tissue layer. Proboscis with two muscle layers and two muscle crosses. Body wall musculature with slender diagonal layer.

Habitat:
Found intertidally beneath rocks and stones embedded in muddy sediments from the mid-tide level downwards, often in muds blackened by decaying organic matter.

Distribution:
The known geographic range extends from the British Isles to the coasts of Sweden, Belgium and France, though a wider distribution may be masked by the problems of synonymity.

Lineus sanguineus