''Polysiphonia'', known as red hair algae, is a

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 ...

of filamentous

red algae Red algae, or Rhodophyta (, ; ), make up one of the oldest groups of eukaryotic algae. The Rhodophyta comprises one of the largest Phylum, phyla of algae, containing over 7,000 recognized species within over 900 Genus, genera amidst ongoing taxon ...

with about 19

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

on the coasts of the

British Isles The British Isles are an archipelago in the Atlantic Ocean, North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner Hebrides, Inner and Outer Hebr ...

and about 200 species worldwide, including

Crete Crete ( ; , Modern Greek, Modern: , Ancient Greek, Ancient: ) is the largest and most populous of the Greek islands, the List of islands by area, 88th largest island in the world and the List of islands in the Mediterranean#By area, fifth la ...

Greece Greece, officially the Hellenic Republic, is a country in Southeast Europe. Located on the southern tip of the Balkan peninsula, it shares land borders with Albania to the northwest, North Macedonia and Bulgaria to the north, and Turkey to th ...

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean (also known as the Antarctic Ocean), it contains the geographic South Pole. ...

and

Greenland Greenland is an autonomous territory in the Danish Realm, Kingdom of Denmark. It is by far the largest geographically of three constituent parts of the kingdom; the other two are metropolitan Denmark and the Faroe Islands. Citizens of Greenlan ...

. 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 Ceramiales is an order of red algae. It was established by Friedrich Oltmanns in 1904. Families * Callithamniaceae Kützing, 1843 * Ceramiaceae Dumortier, 1822 * Choreocolacaceae Sturch * Dasyaceae Kützing, 1843 * Delesseriaceae Bory, 1828 * ...

and family

Rhodomelaceae Rhodomelaceae is estimated to be the largest red algae family, with about 125 genera and over 700 species. Included taxa Rhodomelaceae includes the following tribes and genera: ''Incertae sedis or is a term used for a taxonomy (biology ...

Description

''Polysiphonia'' is a red alga,

polysiphonous Polysiphonous describes an algal Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms rang ...

and usually well branched, with some plants reaching a length of about 30 cm. They are attached by

rhizoid Rhizoids are protuberances that extend from the lower epidermal cells of bryophytes and algae. They are similar in structure and function to the root hairs of vascular land plants. Similar structures are formed by some fungi. Rhizoids may be un ...

s or

haptera A holdfast is a root-like structure that anchors aquatic sessile organisms, such as seaweed, other sessile algae, stalked crinoids, benthic cnidarians, and sponges, to the substrate. Holdfasts vary in shape and form depending on both the specie ...

to a rocky surface or other alga. 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 ...

(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

frond A frond is a large, divided leaf. In both common usage and botanical nomenclature, the leaves of ferns are referred to as fronds and some botanists restrict the term to this group. Other botanists allow the term frond to also apply to the lar ...

s. Its cuticle contains

bromine Bromine is a chemical element; it has chemical symbol, symbol Br and atomic number 35. It is a volatile red-brown liquid at room temperature that evaporates readily to form a similarly coloured vapour. Its properties are intermediate between th ...

. 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 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 ...

spiral In mathematics, a spiral is a curve which emanates from a point, moving further away as it revolves around the point. It is a subtype of whorled patterns, a broad group that also includes concentric objects. Two-dimensional A two-dimension ...

, and the width and length of thalli.

Distribution and ecology

Species have been recorded from

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

and

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

and South America, islands in the Pacific Ocean, South Africa, southwest Asia, Japan, Greenland and Antarctica. The species are entirely marine, found growing on rock, other algae, mussels or limpets and artificial substrata etc. from mid-Littoral zone, littoral to at least 27 m depth. Many species are abundant in Tide pool, rock pools. ''Polysiphonia lanosa'' is commonly found growing on ''Ascophyllum nodosum.''

Reproduction and life cycle

The life-cycle of the red algae has three stages (wikt:triphasic, triphasic). In ''Polysiphonia'' it consists of a sequence of a gametangium, gametangial, carpospore, carpospoangial and Red algae#Life cycle, tetrasporangial phases.Smith, G.M. 1955. ''Cryptogamic Botany Algae and Fungi. Volume 1.'' Second Edition. p.337 Male (Ploidy#Haploid and monoploid, haploid) plants (the male gametophytes) produce spermatia and the female plants (the female gametophytes) produce the carpogonium (the haploid carpogonium) which remains attached to the parent female plant. After fertilization the Ploidy#Diploid, diploid Cell nucleus, nucleus migrates and fuses with an auxiliary cell. A complex series of fusions and developments follow as the diploid zygote develops to become the carposporophyte, this is a separate phase of the life-cycle and is entirely parasitism, 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 tetrasporaphyte, 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.

Species

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

Notes

References

External links

Images
of ''Polysiphonia'' at Algaebase * {{Authority control Rhodomelaceae Red algae genera