Fucus | |
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Fucus serratus | |
Scientific classification | |
Domain: | Eukaryota |
Clade: | Diaphoretickes |
Clade: | SAR |
Clade: | Stramenopiles |
Phylum: | Gyrista |
Subphylum: | Ochrophytina |
Class: | Phaeophyceae |
Order: | Fucales |
Family: | Fucaceae |
Genus: | Fucus L. |
Species | |
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Fucus is a genus of brown algae found in the intertidal zones of rocky seashores almost throughout the world.
The thallus is perennial with an irregular or disc-shaped holdfast or with haptera. [1] The erect portion of the thallus is dichotomous or subpinnately branched, flattened and with a distinct midrib. Gas-filled pneumatocysts (air-vesicles) are present in pairs in some species, one on either side of the midrib. The erect portion of the thallus bears cryptostomata and caecostomata (sterile surface cavities). The base of the thallus is stipe-like due to abrasion of the tissue lateral to the midrib and it is attached to the rock by a holdfast. The gametangia develop in conceptacles embedded in receptacles in the apices of the final branches. They may be monoecious or dioecious. [2]
These algae have a relatively simple life cycle and produce only one type of thallus which grows to a maximum size of 2 m.[ citation needed ] Fertile cavities, the conceptacles, containing the reproductive cells are immersed in the receptacles near the ends of the branches. After meiosis, oogonia and antheridia, the female and male reproductive organs, produce egg cells and sperm respectively that are released into the sea where fertilisation takes place. The resulting zygote develops directly into the diploid plant. This contrasts with the life cycle of the flowering plant, [3] [4] where the egg cells and sperm are produced by a haploid multicellular generation, albeit very strongly reduced, and the egg cells are fertilised within the ovules of the parent plant and then released as seeds.
Species of Fucus are recorded almost worldwide. They are dominant on the shores of the British Isles, [5] the northeastern coast of North America [6] and California. [3]
In the British Isles these larger brown algae occur on sheltered shores in fairly well defined zones along the shore from high-water mark to below low water mark. On the more exposed shores not all of these species can be found and on very exposed shores few, if any, occur. Pelvetia canaliculata forms a zone at the top of the shore. Just below this Fucus spiralis , Fucus vesiculosus, Fucus serratus and Laminaria form clear zones, one below the other, along the shore down to low water mark. On sheltered shores Ascophyllum nodosum usually forms a broad and dominating zone along the shore at the mid-littoral. Other brown algae can be found at the low-littoral such as Himanthalia , Laminaria saxatilis and Alaria esculenta . Small green and red algae and animals occur, protected under these large brown algae. [7] When washed up on beaches, kelp flies such as Coelopa pilipes feed and breed on Fucus algae.
In Scotland and Norway, up until the mid-19th century, several seaweed species from Fucus and other genera were harvested, dried, burned to ash, and further processed to become "kelp", which was a type of soda ash that was less costly in Britain than the barilla imported from Spain. It has an alkali content of about 2.5%–5% that was mainly sodium carbonate (Na2CO3), used in soapmaking, glassmaking, and other industries. The purest barilla had a sodium carbonate concentration of about 30%. The seaweed was also used as fertilizer for crop land in the same areas in which it was harvested. [8] [Note 1]
Fucus species can also be used for thalassotherapy, along with other species such as Turkish towel ( Chondracanthus exasperatus ), feather boa ( Egregia menziesii ), and finger kelp ( Laminaria digitata ). [9]
In 2005, it was announced that bacteria grown on Fucus have the ability to attack and kill the MRSA superbacterium. [10]
Because of their easily accessible apolar eggs and free-floating zygotes, several Fucus species have been used as model organisms to study cell polarity, the development of growth axes, and the role of the cell wall in establishing and maintaining cell identity. [11] [12] [13] [14] [15]
The seaweed fly, Coelopa frigida , together with other species of Coelopa , are known to feed, mate, and create habitats out of different species of Fucus. This is of particular notice when the Fucus is stranded on the beach and not when it is submerged under seawater. With increasing amounts of seaweed washing up on shores, there is an increasing recognition of Fucus and their close pairing with Coelopa.
This list of species of Fucus excludes names of uncertain status: [16] [17]
* Species recorded around the coast of Britain. [5]
F. distichus is up to 10 cm long with a short stout cylindrical stipe, branching dichotomous, flat and with a mid-rib. [18] F. distichus subsp. edentatus was first described from Shetland by Börgesen in 1903. Powell found F. distichus subsp. anceps on the north coast of Caithness. It had also been recorded from: Orkney, Fair Isle, St Kilda and the Outer Hebrides in Scotland; in Ireland it had been recorded from Counties Clare, Donegal and Kerry. [19] [20] Two subspecies of F. distichus (subsp. anceps and subsp. edentatus) have been described from the British Isles. [19]
Fucus distichus is the organism used as a model to study the development of cell polarity, since it forms an apolar zygote that can develop polarity given a varying number of gradients.
F. serratus, toothed wrack, is the most distinctive of all the Fucus species. It clearly shows a distinctive serrated edge to the frond not shown by the other species of the genus. [21]
F. spiralis is one of the three most common algae on the shores of the British Isles. It grows to about 40 cm long and does not show air bladders as found on F.vesiculosus or toothed edges as found on F. serratus. It forms a zone near the top of the shore above the zones of F. vesiculosus and F. serratus.
This is one of the most common species of Fucus, common on most shores in the mid-littoral. It has the common name "bladder wrack", and is readily identified by a distinct mid-rib and air vesicles in pairs on either side of the mid-rib. [22]
Fucus vesiculosus, known by the common names bladderwrack, black tang, rockweed, sea grapes, bladder fucus, sea oak, cut weed, dyers fucus, red fucus and rock wrack, is a seaweed found on the coasts of the North Sea, the western Baltic Sea and the Atlantic and Pacific Oceans. It was the original source of iodine, discovered in 1811, and was used extensively to treat goitre, a swelling of the thyroid gland related to iodine deficiency.
Brown algae 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 regions. Many brown algae, such as members of the order Fucales, commonly grow along rocky seashores. Most brown algae live in marine environments, where they play an important role both as food and as a potential habitat. For instance, Macrocystis, a kelp of the order Laminariales, may reach 60 m (200 ft) in length and forms prominent underwater kelp forests that contain a high level of biodiversity. Another example is Sargassum, which creates unique floating mats of seaweed in the tropical waters of the Sargasso Sea that serve as the habitats for many species. Some members of the class, such as kelps, are used by humans as food.
Strangford Lough is a large sea lough or inlet in County Down, in the east of Northern Ireland. It is the largest inlet in Ireland and the wider British Isles, covering 150 km2 (58 sq mi). The lough is almost fully enclosed by the Ards Peninsula and is linked to the Irish Sea by a long narrow channel at its southeastern edge. The main body of the lough has at least seventy islands along with many islets (pladdies), bays, coves, headlands and mudflats. It is part of the Strangford and Lecale Area of Outstanding Natural Beauty. Strangford Lough was designated as Northern Ireland's first Marine Conservation Zone in 2013, and has been designated a Special Area of Conservation for its important wildlife.
Ascophyllum nodosum is a large, common cold water seaweed or brown alga (Phaeophyceae) in the family Fucaceae. Its common names include knotted wrack, egg wrack, feamainn bhuí, rockweed, knotted kelp and Norwegian kelp. It grows only in the northern Atlantic Ocean, along the north-western coast of Europe including east Greenland and the north-eastern coast of North America. Its range further south of these latitudes is limited by warmer ocean waters. It dominates the intertidal zone. Ascophyllum nodosum has been used numerous times in scientific research and has even been found to benefit humans through consumption.
Alaria esculenta is an edible seaweed, also known as dabberlocks or badderlocks, or winged kelp, and occasionally as Atlantic Wakame. It is a traditional food along the coasts of the far north Atlantic Ocean. It may be eaten fresh or cooked in Greenland, Iceland, Scotland and Ireland. It is the only one of twelve species of Alaria to occur in both Ireland and in Great Britain.
Laminaria is a genus of brown seaweed in the order Laminariales (kelp), comprising 31 species native to the north Atlantic and northern Pacific Oceans. This economically important genus is characterized by long, leathery laminae and relatively large size. Some species are called Devil's apron, due to their shape, or sea colander, due to the perforations present on the lamina. Others are referred to as tangle. Laminaria form a habitat for many fish and invertebrates.
Fucus serratus is a seaweed of the north Atlantic Ocean, known as toothed wrack, serrated wrack, or saw rack.
Fucoidan is a long chain sulfated polysaccharide found in various species of brown algae. Commercially available fucoidan is commonly extracted from the seaweed species Fucus vesiculosus (wracks), Cladosiphon okamuranus, Laminaria japonica and Undaria pinnatifida (wakame). Variant forms of fucoidan have also been found in animal species, including the sea cucumber.
Fucus spiralis is a species of seaweed, a brown alga, living on the littoral shore of the Atlantic coasts of Europe and North America. It has the common names of spiral wrack and flat wrack.
Wrack is part of the common names of several species of seaweed in the family Fucaceae. It may also refer more generally to any seaweeds or seagrasses that wash up on beaches and may accumulate in the wrack zone.
The Ballantine scale is a biologically defined scale for measuring the degree of exposure level of wave action on a rocky shore. Devised in 1961 by W. J. Ballantine, then at the zoology department of Queen Mary College, London, the scale is based on the observation that where shoreline species are concerned "Different species growing on rocky shores require different degrees of protection from certain aspects of the physical environment, of which wave action is often the most important." The species present in the littoral zone therefore indicate the degree of the shore's exposure.
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. Conceptacles are present in Corallinaceae, and Hildenbrandiales, as well as the brown Fucales. In the Fucales there is no haploid phase in the reproductive cycle and therefore no alternation of generations. The thallus is a sporophyte. The diploid plants produce male (antheridia) and female (oogonia) gametangia by meiosis. The gametes are released into the surrounding water; after fusion, the zygote settles and begins growth.
Phlorotannins are a type of tannins found in brown algae such as kelps and rockweeds or sargassacean species, and in a lower amount also in some red algae. Contrary to hydrolysable or condensed tannins, these compounds are oligomers of phloroglucinol (polyphloroglucinols). As they are called tannins, they have the ability to precipitate proteins. It has been noticed that some phlorotannins have the ability to oxidize and form covalent bonds with some proteins. In contrast, under similar experimental conditions three types of terrestrial tannins apparently did not form covalent complexes with proteins.
Ulva intestinalis is a green alga in the family Ulvaceae, known by the common names sea lettuce, green bait weed, gutweed, and grass kelp. Until they were reclassified by genetic work completed in the early 2000s, the tubular members of the sea lettuce genus Ulva were placed in the genus Enteromorpha.
Fucus distichus or rockweed is a species of brown alga in the family Fucaceae to be found in the intertidal zones of rocky seashores in the Northern Hemisphere, mostly in rock pools.
Fucus gardneri is a species of seaweed, a brown alga living on the littoral shore of the Pacific coasts of North America. It has the common names of rockweed and bladderwrack.
Fucus guiryi is a brown alga in the family Fucaceae. It is known from numerous locations along the east coast of the North Atlantic Ocean, from Ireland to the Canary Islands.
Fucus ceranoides is a species of brown algae found in the littoral zone of the sea shore.
Saccharina dentigera is a species of brown algae, in the family Laminariaceae. It is native to shallow water in the northeastern Pacific Ocean from the Gulf of Alaska to Baja California.
Coelopa pilipes is a common European species of kelp fly. It was described by A. H. Haliday in 1838. Their appearance differs greatly from that of other Coelopa flies.