Polysiphonia is a genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of red alga with about 19 species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 on the coasts of the British Isles
British Isles
The British Isles are a group of islands off the northwest coast of continental Europe that include the islands of Great Britain and Ireland and over six thousand smaller isles. There are two sovereign states located on the islands: the United Kingdom of Great Britain and Northern Ireland and...

  and about 200 species world-wide, including Crete
Crete is the largest and most populous of the Greek islands, the fifth largest island in the Mediterranean Sea, and one of the thirteen administrative regions of Greece. It forms a significant part of the economy and cultural heritage of Greece while retaining its own local cultural traits...

 in Greece
Greece , officially the Hellenic Republic , and historically Hellas or the Republic of Greece in English, is a country in southeastern Europe....

, Antarctica and Greenland
Greenland is an autonomous country within the Kingdom of Denmark, located between the Arctic and Atlantic Oceans, east of the Canadian Arctic Archipelago. Though physiographically a part of the continent of North America, Greenland has been politically and culturally associated with Europe for...

.  Its members are known by a number of common names.Recorded common names are olann dhearg, craonach, cúnach triosgar, cluaisíní, mileara, millreacha, salata tou yialou (σαλάτα του γιαλού) and lobster horns. It is in the Order Ceramiales and Family Rhodomelaceae. 


Polysiphonia is a red alga, filamentous and usually well branched some plants reaching a length of about 30 cm. They are attached by rhizoids or haptera  to a rocky surface or other alga. The thallus (tissue) consists of fine branched filaments each with a central axial filament supporting pericentral cells. The number of these pericentral cells, 4–24, is used in identification.  Polysiphonia elongata  shows a central axial cell with 4 periaxial cells with cortical cells growing over the outside on the older fronds.  Its cuticle contains bromine
Bromine ") is a chemical element with the symbol Br, an atomic number of 35, and an atomic mass of 79.904. It is in the halogen element group. The element was isolated independently by two chemists, Carl Jacob Löwig and Antoine Jerome Balard, in 1825–1826...


Features used in identification include the number of pericentral cells, the cortication of main branches, constriction of young branches at their base, whether the branching dichotomous or spiral, and the width and length of thalli.

Distribution and ecology

Species have been recorded from Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

, Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

 and New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

, North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

 and South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

, islands in the Pacific Ocean, South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...

, southwest Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

, Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

, Greenland and Antarctica. 

The species are entirely marine, found growing on rock, other algae, mussels or limpets and artificial substrata etc from mid-littoral to at least 27 m depth. Many species are abundant in rock pools.  Polysiphonia lanosa is commonly found growing on Ascophyllum nodosum
Ascophyllum nodosum
Ascophyllum nodosum is a large, common brown alga in the family Fucaceae, being the only species in the genus Ascophyllum. It is seaweed of the northern Atlantic Ocean, also known as rockweed, Norwegian kelp, knotted kelp, knotted wrack or egg wrack...


Life cycle

The life-cycle of the red algae has three stages (triphasic). In Polysiphonia it consists of a sequence of a gametangial, carposporangial and tetrasporangial phases.  Male (haploid) plants (the male gametophytes) produce sperm
The term sperm is derived from the Greek word sperma and refers to the male reproductive cells. In the types of sexual reproduction known as anisogamy and oogamy, there is a marked difference in the size of the gametes with the smaller one being termed the "male" or sperm cell...

atia and the female plants (the female gametophytes) produce the carpogonium (the haploid carpogonium) which remains attached to the parent female plant. After fertilization the diploid nucleus
Cell nucleus
In cell biology, the nucleus is a membrane-enclosed organelle found in eukaryotic cells. It contains most of the cell's genetic material, organized as multiple long linear DNA molecules in complex with a large variety of proteins, such as histones, to form chromosomes. The genes within these...

 migrates and fuses with an auxiliary cell. A complex series of fusions and developments follow as the diploid zygote
A zygote , or zygocyte, is the initial cell formed when two gamete cells are joined by means of sexual reproduction. In multicellular organisms, it is the earliest developmental stage of the embryo...

 develops to become the carposporophyte, this is a separate phase of the life-cycle and is entirely parasitic on the female, it is surrounded by the haploid pericarp of the parent female plant. The diploid carpospores produced in the carposporangium when released are non-motile, they settle and grow to form filamentous diploid plants similar to the gametophyte. This diploid plant is the tetrasporophyte which when adult produced spores in fours after meiosis. These spores settle and grow to become the male and female plants thus completing the cycle. 


The species currently recognized are:
  • P. abscissa
  • P. abscissoides
  • P. acanthina
  • P. acuminata
  • P. adamsiae
  • P. adriatica
  • P. amphibolis
  • P. anisogona
  • P. anomala
  • P. arachnoidea
  • P. arctica
  • P. aterrima
  • P. atlantica
  • P. atra
  • P. atricapilla
  • P. australiensis
  • P. azorica
  • P. bajacali
  • P. banyulensis
  • P. barbatula
  • P. baxteri
  • P. beaudettei
  • P. beguinotii
  • P. bicornis
  • P. biformis
  • P. bifurcata
  • P. binneyi
  • P. blandii
  • P. boergesenii
  • P. boldii
  • P. breviarticulata
  • P. brevisegmenta
  • P. brodiei
  • P. caespitosa
  • P. callithamnioides
  • P. cancellata
  • P. capucina
  • P. carettia
  • P. caspica
  • P. castagnei
  • P. castelliana
  • P. ceramiaeformis
  • P. cladorhiza
  • P. coacta
  • P. codicola
  • P. collinsii
  • P. confusa
  • P. constricta
  • P. corymbosa
  • P. crassa
  • P. crassicollis
  • P. crassiuscula
  • P. curta
  • P. dasyoeformis
  • P. daveyae
  • P. decipiens
  • P. decussata
  • P. delicatula
  • P. denudata
  • P. derbesii
  • P. deusta
  • P. devoniensis
  • P. dichotoma
  • P. dotyi
  • P. dumosa
  • P. echigoensis
  • P. echinata
  • P. elongata, lobster horns
  • P. erythraea
  • P. exilis
  • P. fernandeziana
  • P. fibrata
  • P. fibrillosa
  • P. figariana
  • P. flabelliformis
  • P. flabellulata
  • P. flexella
  • P. flexicaulis
  • P. flocculosa
  • P. foeniculacea
  • P. foetidissima
  • P. forfex
  • P. fracta
  • P. fragilis
  • P. fucoides
  • P. funebris
  • P. furcellata
  • P. fuscorubens
  • P. gonatophora
  • P. gracilis
  • P. guadalupensis
  • P. guernisacii
  • P. hancockii
  • P. hapalacantha
  • P. haplodasyae
  • P. hassleri
  • P. havanensis
  • P. havaniensis
  • P. hemisphaerica
  • P. hendryi
  • P. herpa
  • P. hirta
  • P. hochstetteriana
  • P. hockstetteriana
  • P. homoia
  • P. howei
  • P. implexa
  • P. incompta
  • P. indigena
  • P. infestans
  • P. isogona
  • P. japonica
  • P. johnstonii
  • P. kampsaxii
  • P. kappannae
  • P. kieliana
  • P. kotschyana
  • P. kowiensis
  • P. lanosa
  • P. letestui
  • P. macounii
  • P. marchantae
  • P. masonii
  • P. mollis
  • P. morrowii
  • P. mottei
  • P. muelleriana
  • P. namibiensis
  • P. nathanielii
  • P. neglecta
  • P. nhatrangense
  • P. nhatrangensis
  • P. nigra
  • P. nigrescens
  • P. nizamuddinii
  • P. opaca
  • P. ornata
  • P. orthocarpa
  • P. pacifica
  • P. paniculata
  • P. paradoxa
  • P. parthasarathyi
  • P. parvula
  • P. pentamera
  • P. perforans
  • P. pernacola
  • P. perriniae
  • P. platycarpa
  • P. plectocarpa
  • P. plectrocarpa
  • P. polychroma
  • P. polyspora
  • P. porrecta
  • P. propagulifera
  • P. pseudovillum
  • P. pulvinata
  • P. quadrata
  • P. ramentacea
  • P. requienii
  • P. rhododactyla
  • P. rhunensis
  • P. rigidula
  • P. rudis
  • P. saccorhiza
  • P. sadoensis
  • P. sanguinea
  • P. scopulorum
  • P. senticulosa
  • P. sertularioides
  • P. setigera
  • P. shepherdii
  • P. simplex
  • P. simulans
  • P. sinicola
  • P. sonorensis
  • P. sparsa
  • P. sphaerocarpa
  • P. spinosa
  • P. stricta
  • P. strictissima
  • P. stuposa
  • P. subtilissima
  • P. subulata
  • P. subulifera
  • P. succulenta
  • P. tapinocarpa
  • P. teges
  • P. tenerrima
  • P. tenuistriata
  • P. tepida
  • P. tokidae
  • P. tongatensis
  • P. tripinnata
  • P. triton
  • P. tsudana
  • P. tuberosa
  • P. tuticorinensis
  • P. unguiformis
  • P. upolensis
  • P. urbana
  • P. urbanoides
  • P. urceolata
  • P. utricularis
  • P. virgata
  • P. yonakuniensis

External links

  • Images of Polysiphonia at Algaebase
    AlgaeBase is a global species database of information on all groups of algae, as well as one group of flowering plants, the sea-grasses.AlgaeBase evolved from Michael Guiry's seaweed website, and has grown into a database of algae from throughout the world, and in freshwater, terrestrial, and...

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