''Himanthalia elongata'' is a

brown alga Brown algae (: alga) are a large group of multicellular algae comprising the class Phaeophyceae. They include many seaweeds located in colder waters of the Northern Hemisphere. Brown algae are the major seaweeds of the temperate and polar reg ...

in the order

Fucales The Fucales (fucoids) are an order in the brown algae (class Phaeophyceae). The list of families in the Fucales, as well as additional taxonomic information on algae, is publicly accessible at Algaebase. The class Phaeophyceae is included wit ...

, also known by the common names thongweed, sea thong and sea spaghetti. It is found in the north east Atlantic Ocean and the North Sea. According to the

World Register of Marine Species The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive catalogue and list of names of marine organisms. Content The content of the registry is edited and maintained by scien ...

''Himanthalia elongata'' is the only member of its

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

, ''Himanthalia'' Lyngbye, 1819 and the only member of its

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

, Himanthaliaceae ( Kjellman) De Toni, 1891.

Description

''Himanthalia elongata'' is a common brown alga of the lower shore. The

thallus Thallus (: thalli), from Latinized Greek (), meaning "a green shoot" or "twig", is the vegetative tissue of some organisms in diverse groups such as algae, fungi, some liverworts, lichens, and the Myxogastria. A thallus usually names the entir ...

is at first a small flattened or saucer-shaped disc up to three centimetres wide with a short stalk. In the autumn or winter, long thongs grows from the centre of this, branching

dichotomous A dichotomy () is a partition of a set, partition of a whole (or a set) into two parts (subsets). In other words, this couple of parts must be * jointly exhaustive: everything must belong to one part or the other, and * mutually exclusive: nothi ...

ly a number of times. They grow fast and can reach up to two metres by the following summer when they become mature. They bear the

conceptacle Conceptacles are specialized cavities of marine and freshwater algae that contain the reproductive organs. They are situated in the receptacle and open by a small ostiole.Boney, A.D. (1969). ''A Biology of Marine Algae''. Hutchinson Educational ...

s, the reproductive organs, and begin to decay when the

gamete A gamete ( ) is a Ploidy#Haploid and monoploid, haploid cell that fuses with another haploid cell during fertilization in organisms that Sexual reproduction, reproduce sexually. Gametes are an organism's reproductive cells, also referred to as s ...

s have been released into the water. The discs live for two or three years.Thongweed - ''Himanthalia elongata''

Marine Life Information Network The Marine Life Information Network (MarLIN) is an information system for marine biodiversity for Great Britain and Ireland. MarLIN was established in 1998 by the Marine Biological Association The Marine Biological Association of the United ...

. Retrieved 2011-09-23.''Himanthalia elongata'' (Linnaeus) S.F. Gray
The Seaweed Site. Retrieved 2011-09-23.

Distribution and habitat

''Himanthalia elongata'' is found in the

Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by the countries of Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden, and the North European Plain, North and Central European Plain regions. It is the ...

, the

North Sea The North Sea lies between Great Britain, Denmark, Norway, Germany, the Netherlands, Belgium, and France. A sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian Se ...

and the north east

Atlantic Ocean The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...

from

Scandinavia Scandinavia is a subregion#Europe, subregion of northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. ''Scandinavia'' most commonly refers to Denmark, Norway, and Sweden. It can sometimes also ...

, through

Ireland Ireland (, ; ; Ulster Scots dialect, Ulster-Scots: ) is an island in the North Atlantic Ocean, in Northwestern Europe. Geopolitically, the island is divided between the Republic of Ireland (officially Names of the Irish state, named Irelan ...

, and south to

Portugal Portugal, officially the Portuguese Republic, is a country on the Iberian Peninsula in Southwestern Europe. Featuring Cabo da Roca, the westernmost point in continental Europe, Portugal borders Spain to its north and east, with which it share ...

.''Himanthalia elongata'' (Linnaeus) S.F.Gray
AlgaeBase. Retrieved 2011-09-23. It is found on gently shelving rocky shores in the lower

littoral zone The littoral zone, also called litoral or nearshore, is the part of a sea, lake, or river that is close to the shore. In coastal ecology, the littoral zone includes the intertidal zone extending from the high water mark (which is rarely flood ...

and the

sublittoral zone The neritic zone (or sublittoral zone) is the relatively shallow part of the ocean above the drop-off of the continental shelf, approximately in depth. From the point of view of marine biology it forms a relatively stable and well-illuminated ...

particularly on shores with moderate wave exposure. It is sometimes abundant and forms a distinct zone just below the ''

Fucus serratus ''Fucus serratus'' is a seaweed of the north Atlantic Ocean, known as toothed wrack, serrated wrack, or saw wrack. Description and reproduction ''Fucus serratus'' is a robust alga, olive-brown in colour and similar to ''Fucus vesiculosus'' an ...

'' zone.

References

{{taxonbar, from=Q1636443, from2=Q18364313, from3=Q18364310 Fucales Edible algae