''Chorda filum'', commonly known as dead man's rope or sea lace among other names, is a species of

brown algae Brown algae (singular: alga), comprising the class Phaeophyceae, are a large group of multicellular algae, including many seaweeds located in colder waters within the Northern Hemisphere. Brown algae are the major seaweeds of the temperate and po ...

in the genus '' Chorda''. It is widespread in the temperate waters of the northern hemisphere. The species has numerous other common names related to its physical appearance. These include mermaid's tresses, cat's gut or sea-catgut, bootlace weed, sea-twine, and mermaid's fishing line.

Description

''Chorda filum'' have typically long, unbranched and hollow rope-like brown fronds about in diameter but can reach to lengths of . The holdfast is disc-shaped. ''C. filum'' is found in sheltered marine and estuarine bodies of water at depths of up to . They are usually anchored to loose substrates like gravel and pebbles or other

macroalgae Seaweed, or macroalgae, refers to thousands of species of macroscopic, multicellular, marine algae. The term includes some types of ''Rhodophyta'' (red), ''Phaeophyta'' (brown) and ''Chlorophyta'' (green) macroalgae. Seaweed species such as k ...

and

eelgrass Eelgrass is a common name for several plants and may refer to: * ''Zostera'', marine eelgrass * ''Vallisneria ''Vallisneria'' (named in honor of Antonio Vallisneri) is a genus of freshwater aquatic plant, commonly called eelgrass, tape grass o ...

. ''C. filum'' grow at an average of per month, with the spiral-shaped, often gas-inflated, termini of fronds being dead, but receiving replacement by growth from a sub-terminal

meristem The meristem is a type of tissue found in plants. It consists of undifferentiated cells (meristematic cells) capable of cell division. Cells in the meristem can develop into all the other tissues and organs that occur in plants. These cells conti ...

. They are annuals and die during winter. The fronds bear short colorless hairs in summer.Bunker, F. StP. D, Maggs, C.A., Brodie, J.A., Bunker, A. 2017 ''Seaweeds of Britain and Ireland.'' Second Edition. Wild Nature Press, Plymouth, UK ''Chorda filum'' is similar to ''Halosiphon tomentosus''. However ''H. tomentosus'' is less common and is covered with long brown

paraphyses Paraphyses are erect sterile filament-like support structures occurring among the reproductive apparatuses of fungi, ferns, bryophytes and some thallophytes. The singular form of the word is paraphysis. In certain fungi, they are part of the fe ...

or sterile hairs.

Habitat

''Chorda filum'' is to be found in very sheltered shores. It may be common or abundant near low water and in the sublittoral to areas in mud and sand.

Distribution

''Chorda filum'' is found in temperate waters in the northern hemisphere, on the coasts of the northern

Atlantic The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe an ...

and

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

oceans. Within this, it is noted as being widespread and generally common around

Ireland Ireland ( ; ga, Éire ; Ulster Scots dialect, Ulster-Scots: ) is an island in the Atlantic Ocean, North Atlantic Ocean, in Northwestern Europe, north-western Europe. It is separated from Great Britain to its east by the North Channel (Grea ...

Great Britain Great Britain is an island in the North Atlantic Ocean off the northwest coast of continental Europe. With an area of , it is the largest of the British Isles, the largest European island and the ninth-largest island in the world. It is ...

, the

Shetland Isles Shetland, also called the Shetland Islands and formerly Zetland, is a subarctic archipelago in Scotland lying between Orkney, the Faroe Islands and Norway. It is the northernmost region of the United Kingdom. The islands lie about to the ...

, and the

Isle of Man ) , anthem = "O Land of Our Birth" , image = Isle of Man by Sentinel-2.jpg , image_map = Europe-Isle_of_Man.svg , mapsize = , map_alt = Location of the Isle of Man in Europe , map_caption = Location of the Isle of Man (green) in Europe ...

.Hardy,F.G. and Guiry, M.D. 2003 ''A Check-list and Atlas of Seaweeds of Britain and Ireland''. The British Phycological Society,

References

External links

* {{Taxonbar, from=Q117405 Laminariales Species described in 1753 Taxa named by John Stackhouse