Fucus 1424029 204712976 2008-04-10T15:45:37Z Plantsurfer 1750837 refs {{mergefrom|Wrack (science)|date=September 2007}} {{Taxobox | name = ''Fucus'' | image = Fucus_serratus2.jpg | image_width = 250px | image_caption = ''[[Toothed wrack|Fucus serratus]]'' | domain = [[Eukaryota]] | regnum = [[Chromalveolata]] | phylum = [[Heterokont]]ophyta | classis = [[Brown alga|Phaeophyceae]] | ordo = [[Fucales]] | familia = [[Fucaceae]] | genus = '''''Fucus''''' | genus_authority = [[Carolus Linnaeus|L.]] | subdivision_ranks = [[Species]] | subdivision = ''See text'' }} '''''Fucus''''' is a [[genus]] of [[brown alga]] ([[seaweed]]) in the Class [[Phaeophyceae]] to be found in the intertidal zones of rocky shores. It is a common genus found on the [[Atlantic Ocean|Atlantic]] coasts of Europe and North America. ==Description and life cycle== The [[thallus]] is perennial with an irregular or disc-shaped [[holdfast]] or with haptera&nbsp;<ref name="Stegenga 97">{{cite book |author=H. Stegenga, J. J. Bolton & R. J. Anderson |year=1997 |title=Seaweeds of the South African West Coast. Contributions from the Bolus Herbarium Volume 18 |id=ISBN 0-7992-1793-X}}</ref>. The erect portion of the thallus is [[dichotomous]] or subpinnately branched, flattened and with a distinct midrib. Gas-filled [[pneumatocyst]]s (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.&nbsp;<ref>{{cite web |url=http://www.seaweed.ie/algae/fucus.lasso |title=''Fucus'' |author=Michael Guiry |accessdate=2007-04-28 |publisher=[[National University of Ireland, Galway]]}}</ref> These algae have a relatively simple life cycle and produce only one type of [[thallus]] which grows to a maximum size of 2&nbsp;[[metre|m]]. Fertile cavities, the conceptacles, containing the reproductive cells are immersed in the receptacles near the ends of the branches. After [[meiosis]] [[oogonia]] and [[antheridia]] are produced and released, [[fertilization]] follows and the [[zygote]] develops directly into the diploid plant. It may be considered to be analogous to the life cycle of the flowering plant.&nbsp;<ref name="Abbott and Hollenberg 76"/><ref name="Hoek, 1995">{{cite book |author=C. van den Hoek, D. G. Mann & H. M. Jahns |year=1995 |title=Algae: An Introduction to Phycology |publisher=[[Cambridge University Press]], Cambridge |id=ISBN 0-521-39419-9}}</ref> but in algae the oogonia are released and fertilised in the sea while in [[flowering plant]]s the [[ovules]] are fertilised while attached to the parent plant and then released as a [[seed]]. ==Distribution and ecology== Species of ''Fucus'' are recorded almost world-wide. They are dominant on the shores of the [[British Isles]]&nbsp;<ref name="Hardy and Guiry 06">{{Cite book |author='''F. G. Hardy & M. D. Guiry''' |year=2006 |title=A Checklist and Atlas of the Seaweeds of Britain and Ireland |publisher=[[British Phycological Society]], London |id=ISBN 3-906166-35-X}}</ref>, the northeastern coast of North America&nbsp;<ref name="Taylor 72">{{cite book |author=W. R. Taylor |year=1972 |title=Marine Algae of the Northeastern Coast of North America |publisher=Ann Arbor, [[University of Michigan Press]] |id=ISBN 0-472-04904-6}}</ref> and California&nbsp;<ref name="Abbott and Hollenberg 76">{{cite book |author=I. A. Abbott & G. J. Hollenberg |year=1976 |title=Marine Algae of California |publisher=[[Stanford University Press]] |id=ISBN 0-8047-0867-3}}</ref>. 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]]'' and ''[[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]]. On very exposed shores few if, any plants, of these species can be found. 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 protceted under these large brown algae&nbsp;<ref name="Lewis 64">{{cite book |author=J. R. Lewis |year=1964 |title=The Ecology of Rocky Shores |publisher=[[The English Universities Press]] Ltd, London}}</ref>. ==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. It has an [[alkali]] content of about 2.5–5% that was mainly [[sodium carbonate]] (Na<sub>2</sub>CO<sub>3</sub>); alkali is essential to soapmaking, glassmaking, and other industries. The seaweed was also used as fertiliser for crop land in the same areas in which it was harvested&nbsp;<ref name="Clow52">{{cite book |author='''A. Clow & N. L. Clow''' |year=1952 |title=Chemical Revolution |piblisher=Ayer Co Pub |pages=65–90 |id=ISBN 0-836-91909-2}}<br />Clow and Clow 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 do not reflect modern taxonomy for these species, which has been updated using Algaebase</ref>. 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&nbsp;{{Verify source|date=July 2007}}. In 2005, it was announced that [[bacteria]] grown on ''Fucus'' have the ability to attack and kill the [[MRSA]] superbug&nbsp;<ref>{{cite news|url=http://news.bbc.co.uk/1/hi/scotland/4561062.stm|title=Sponge puzzles superbug experts|publisher=[[BBC News]]|date=[[2005-12-26]]}}</ref>. ==Taxonomy== This list of species of ''Fucus'' excludes names of uncertain status&nbsp;<ref>{{cite web |work=[[AlgaeBase]] |title=''Fucus'' Linnaeus 1753: 1158 |url=http://www.algaebase.org/generadetail.lasso?genus_id=71 |accessdate=2006-08-21 |author=M. D. Guiry |year=2006}}</ref>: * ''[[Fucus ceranoides]]'' [[Carolus Linnaeus|L.]]* * ''[[Fucus chalonii]]'' [[Feldmann]] * ''[[Fucus cottonii]]'' [[M.J. Wynne]] & [[Magne]] *(=''Fucus cottonii'' M.J.Wynne & Magne ''nom. illeg.'') * ''[[Fucus distichus]]'' [[Carolus Linnaeus|L.]] * * ''[[Fucus evanescens]]'' [[Carl Adolph Agardh|C.Agardh]] * * ''[[Fucus gardneri]]'' [[P.C. Silva]] * ''[[Fucus nereideus]]'' [[John Lightfoot FRS|Lightfoot]] * ''[[Toothed wrack|Fucus serratus]]'' [[Carolus Linnaeus|L.]] — toothed wrack * * ''[[Fucus spermophorus]]'' [[Carolus Linnaeus|L.]] * ''[[Fucus spiralis]]'' [[Carolus Linnaeus|L.]] * * ''[[Fucus tendo]]'' [[Carolus Linnaeus|L.]] * ''[[Fucus vesiculosus]]'' [[Carolus Linnaeus|L.]]— bladder wrack * * ''[[Fucus virsoides]]'' [[J. Agardh]] <nowiki>* </nowiki>= Species recorded around the coast of Britain.&nbsp;<ref name="Hardy and Guiry 06"/> ===''Fucus distichus''=== ''F. distichus'' is up to 10&nbsp;[[centimetre|cm]] long with a short stout cylindrical stipe, branching dichotomous, flat and with a mid-rib&nbsp;<ref name="Russell 78">{{cite book |author=G. Russell |year=1978 |editor=D. E. G. Irvine & J. H. Price |title=Modern Approaches to the Taxonomy of Red and Brown Algae |pages=339–369 |publisher=[[Systematics Association]]}}</ref>. ''F. distichus'' subsp. ''edentatus'' was first described from [[Shetland Islands]] by Börgesen in 1903. Powell found ''F. distichus'' subsp. ''anceps'' on the north coast of [[Caithness]]. It had also been recorded from: [[Orkney Islands]], [[Fair Isle]], [[St Kilda, Scotland|St Kilda]] and the [[Outer Hebrides]] in [[Scotland]]; in [[Ireland]] it had been recorded from Counties [[County Clare|Clare]], [[County Donegal|Donegal]] and [[County Kerry|Kerry]]&nbsp;<ref name="Powella 57">{{Cite journal |quotes=no |author='''H. T. Powell''' |year=1957 |title=Studies in the genus ''Fucus'' L. II. Distribution and ecology of forms of ''Fucus distichus'' L. emend. Powell in Britain and Ireland |journal=[[Journal of the Marine Biology Association of the United Kingdom]] |volume=36 |pages=663–693}}</ref><ref name="Powellb 57">{{Cite journal |quotes=no |author='''H. T. Powell''' |year=1957 |title=Studies in the genus ''Fucus'' L. I. ''Fucus distichus'' L. emend. Powell |journal=[[Journal of the Marine Biology Association of the United Kingdom]] |volume=36 |pages=407–432}}</ref>. Two subspecies of ''F. distichus'' (subsp. ''anceps'' and subsp. ''edentatus'') have been described from the British Isles&nbsp;<ref name="Powella 57"/>. ''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. ===''Fucus serratus''=== {{Main|Fucus serratus}} ''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&nbsp;<ref name="Powell 63">{{Cite book |quotes=no |author='''H. T. Powell''' |year=1963 |chapter=Speciation in the genus ''Fucus'' L., and related genera |publisher=Syst. Assoc. Publ.: 5 |pages=63–77 |editor='''J. P. Harding & N. Tebble''' |title=Speciation in the Sea}}</ref>. ===''Fucus spiralis''=== {{Main|Fucus spiralis}} ''F. spiralis'' is one of the three most common algae on the shores of the British Isles. It grows to about 40&nbsp;[[centimetre|cm]] long and does not show air bladders or a toothed edge as is found on ''F.vesiculosus'' and ''F. serratus''. It forms a zone near the top of the shore above the zones of ''F. vesiculosus'' and ''F. serratus''. ===''Fucus vesiculosus''=== {{Main|bladder wrack}} This is one of the most common species of ''Fucus'', common on most shores in the mid-littoral. Readily identified by a distinct mid-rib and air vesicles in pairs on either side of the mid-rib&nbsp;<ref name="Newton 31">{{cite book |author='''Lily Newton''' |year=1931 |title=A Handbook of the British Seaweeds |publisher=[[British Museum]], London}}</ref>. ==References== {{reflist}} <div class="references-small"><references/></div> ==See also== http://www.pznow.co.uk/marine/wrack.html [[Category:Chromalveolata]] [[Category:Brown algae]] [[da:Blæretang-slægten]] [[es:Fucus]] [[fr:Fucus]] [[it:Fucus]] [[pl:Morszczyn]]