Fucus
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Fucus is a genus of brown alga (seaweed) that lives in the intertidal zones of rocky shores. A common species found on the Atlantic coasts of Europe and North America is Fucus vesiculosus or bladder wrack. On the Pacific coast of North America, the most common species is Fucus gardneri.
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[edit] Description
The thallus is perennial with an irregular or disc-shaped holdfast. 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.
Fucus distichus is the organism used as a model to study the development of cell polarity. F. distichus has many advantages for polarity studies. It forms an apolar zygote that can develop polarity given a varying number of gradients.
[edit] Taxonomy
This list of species of Fucus excludes names of uncertain status. [1]
- Fucus ceranoides L. *
- Fucus chalonii Feldmann
- Fucus cottonii M.J. Wynne & Magne *
- Fucus distichus L. *
- Fucus evanescens C.Agardh *
- Fucus gardneri P.C. Silva
- Fucus nereideus Lightfoot
- Fucus serratus L. — toothed wrack *
- Fucus spermophorus L.
- Fucus spiralis L. *
- Fucus tendo L.
- Fucus vesiculosus L. — bladder wrack *
- Fucus virsoides J. Agardh
* = Species recorded around the coast of Britain
[edit] Ecology
Fucus spiralis, Fucus vesiculosus and Fucus serratus along with Pelvetia canaliculata and Ascophyllum nodosum form zones on the shore of all but the most sheltered and exposed sites on the shores of the British Isles.
[edit] Uses
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 (after consideration of the import duties). This kelp had an alkali content of about 2.5 - 5% that was mainly sodium carbonate (Na2CO3); alkali is essential to soapmaking, glassmaking, and other industries. The seaweed was also used as fertilizer for crop land in the same areas in which it was harvested.[2][3] The purest barilla had a sodium carbonate concentration of about 30%.
It has been reported that to loosen dried earth a machine which sticks probes a meter into the ground and loosens the earth by blasting air in under pressure. Dried seaweed (bladderwrack) can then be injected into the fissures to hold the drainage cracks open.[verification needed]
[edit] Medical
In 2005, it was announced that bacteria grown on Fucus have the ability to attack and kill the MRSA superbug. [4]
[edit] References
- ^ Guiry, M. D. (2006). AlgaeBase version 4.1: Fucus Linnaeus 1753: 1158. National University of Ireland, Galway. Retrieved on August 21, 2006.
- ^ Clow, Archibald and Clow, Nan L. (1952). Chemical Revolution, (Ayer Co Pub, June 1952), pp. 65-90. ISBN 0-8369-1909-2.
- ^ Clow and Clow (1952) indicate four species of seaweed as sources for kelp: Fucus vesiculosus, Ascophyllum nodosum (formerly Fucus nodosus L.), Fucus serratus, and Laminaria digitata (Hudson) J.V. Lamouroux (formerly Fucus digitatus L.). The Fucus species names noted in this book as sources of kelp don't reflect modern taxonomy for these species, which have been updated using Algaebase.
- ^ "Sponge puzzles superbug experts", BBC News, 26 December 2005.
