Porphyra

{{Short description|Genus of seaweed}} {{About||the color known in Greek as ''porphyra''|Tyrian purple|species previously in this genus that have been reclassified as ''pyropia''|Pyropia}} {{Distinguish|Porphyria}} {{Automatic taxobox | image = Porphyra umbilicalis, Porphyra purpurea Helgoland.JPG | image_caption = ''Porphyra umbilicalis'' (right) and ''Porphyra purpurea'' (front), in Heligoland | image_alt = Porphyra umbilicalis (right) and Porphyra purpurea (front), in Heligoland | taxon = Porphyra | authority = C.Agardh 1824 | subdivision_ranks = Species | subdivision_ref = <ref name=WoRMS>Guiry, Michael D. (2012). Porphyra. In: Guiry, M.D. & Guiry, G.M. (2017). AlgaeBase. World-wide electronic publication, National University of Ireland, Galway (taxonomic information republished from AlgaeBase with permission of M.D. Guiry). Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=143808 on 2017-09-06</ref> | subdivision = see text | synonyms = ''Conchocelis'' Batters 1892 ''Phyllona'' J.Hill 1773 | synonyms_ref = <ref name=WoRMS /> }}

'''''Porphyra''''' is a genus of coldwater seaweeds that grow in cold, shallow seawater. More specifically, it belongs to red algae phylum of laver species (from which comes laverbread), comprising approximately 70 species.<ref name="Brodie 02">Brodie, J.A. and Irvine, L.M. 2003. ''Seaweeds of the British Isles.'' Volume 1 Part 3b. The Natural History Museum, London.{{ISBN|1 898298 87 4}}</ref> It grows in the intertidal zone, typically between the upper intertidal zone and the splash zone in cold waters of temperate oceans. In East Asia, it is used to produce the sea vegetable products ''nori'' (in Japan) and ''gim'' (in Korea). There are considered to be 60–70 species of ''Porphyra'' worldwide<ref name="Kain 91">Kain, J.M. 1991. Cultivation of attached seaweeds. in Guiry, M.D. and Blunden, G. 1992. ''Seaweed Resources in Europe: Uses and Potential.'' John Wiley and Sons, Chichester {{ISBN|0-471-92947-6}}</ref> and seven around Britain and Ireland, where it has been traditionally used to produce edible sea vegetables on the Irish Sea coast.<ref name="Hardy and Guiry 06">Hardy, F.G. and Guiry, M.D. 2006. ''A Check-list and Atlas of the Seaweeds of Britain and Ireland.'' British Phycological Society, London. {{ISBN|3-906166-35-X}}</ref> The species ''Porphyra purpurea'' has one of the largest plastid genomes known, with 251 genes.<ref>[https://books.google.com/books?id=E-MXsGnAVAQC&dq=%22red+alga+Porphyra+purpurea+%28251+genes%29%22&pg=PA878 The Chlamydomonas Sourcebook: Organellar and Metabolic Processes Volum 2]</ref>

==Life cycle== ''Porphyra'' displays a heteromorphic alternation of generations.<ref>[http://www.mbari.org/staff/conn/botany/reds/lisa/lhist.htm Porphyra life cycle] {{webarchive|url=https://web.archive.org/web/20070411151035/http://www.mbari.org/staff/conn/botany/reds/lisa/lhist.htm |date=2007-04-11 }} </ref> The thallus we see is the haploid generation; it can reproduce asexually by forming spores which grow to replicate the original thallus. It can also reproduce sexually. Both male and female gametes are formed on the one thallus. The female gametes while still on the thallus are fertilized by the released male gametes, which are non-motile. The fertilized, now diploid, carposporangia after mitosis produce spores (carpospores) which settle, then bore into shells, germinate and form a filamentous stage. This stage was originally thought to be a different species of alga, and was referred to as ''Conchocelis rosea''. That ''Conchocelis'' was the diploid stage of ''Porphyra'' was discovered in 1949 by the British phycologist Kathleen Mary Drew-Baker for the European species ''Porphyra umbilicalis''.<ref>{{cite journal |last1= Drew |first1= Kathleen M. |year=1949 |title= Conchocelis-phase in the life-history of Porphyra umbilicalis (L.) Kütz|journal=Nature |volume= 164|issue= 4174|pages= 748–749|doi= 10.1038/164748a0|bibcode= 1949Natur.164..748D |s2cid= 4134419 }}</ref> It was later shown for species from other regions as well.<ref name="Brodie 02"/><ref name="Thomas 02">Thomas, D. 2002. ''Seaweeds.'' The Natural History Museum, London. {{ISBN|0-565-09175-1}}</ref>

==Food== Most human cultures with access to {{lang|la|Porphyra}} use it as a food or somehow in the diet, making it perhaps the most domesticated of the marine algae,<ref name="Mumford 88">Mumford, T.F. and Miura, A. 4.''Porphyra'' as food: cultivation and economics. in Lembi, C.A. and Waaland, J.R. 1988. ''Algae and Human Affairs.'' Cambridge University Press, Cambridge. {{ISBN|0-521-32115-8}}</ref> known as laver, {{lang|vi|rong biển}} (Vietnamese), ''nori'' (Japanese:{{lang|ja|海苔}}), ''amanori'' (Japanese),<ref name=Abbott>{{cite book|last=Abbott|first=Isabella A|author-link=Isabella Abbott|type=Food and food products from seaweeds|editor1-last=Lembi|editor1-first=Carole A.|editor2-last=Waaland|editor2-first=J. Robert|title=Algae and human affairs|year=1989|pages=141|publisher=Cambridge University Press, Phycological Society of America|isbn= 978-0-521-32115-0}}</ref> ''zakai'', ''gim'' (Korean:{{lang|ko|김}}),<ref name=Abbott /> ''zǐcài'' (Chinese:{{Lang|zh|紫菜}}),<ref name=Abbott /> karengo, ''sloke'' or ''slukos''.<ref name="Kain 91"/> The marine red alga ''Porphyra'' has been cultivated extensively in many Asian countries as an edible seaweed used to wrap the rice and fish that compose the Japanese food sushi and the Korean food ''gimbap''. In Japan, the annual production of ''Porphyra'' species is valued at 100 billion yen (US$1 billion).<ref name="Aoki 06">Aoki, Y. and Kamei, Y. 2006 Preparation of recombinant polysaccharide-degrading enzymes from the marine bacterium, ''Pseudomonas'' sp. ND137 for the production of protoplasts of ''Porphyra yezoensis'' ''Eur. J. Phycol.'' '''41''': 321-328.</ref>

{{lang|la|P.{{nbsp}}umbilicalis}} is harvested from the coasts of Great Britain and Ireland, where it has a variety of culinary uses, including laverbread.<ref name="eatweeds">{{cite web |title= Laver Seaweed – A Foraging Guide to Its Food, Medicine and Other Uses |url=https://www.eatweeds.co.uk/laver-porphyra |website=eatweeds.co.uk |date=30 August 2018 |access-date=22 March 2021}}</ref> In Hawaii, "the species {{lang|la|P.{{nbsp}}atropurpurea}} is considered a delicacy, called {{lang|haw|Limu luau}}".<ref name="eatweeds" /> Porphyra was also harvested by the Southern Kwakiutl, Haida, Seechelt, Squawmish, Nuu-chah-nulth, Nuxalk, Tsimshian, and Tlingit peoples of the North American Pacific coast.<ref name="eatweeds" />

===Vitamin B12=== ''Porphyra'' contains vitamin B12 and one study suggests that it is the most suitable non-meat source of this essential vitamin.<ref>{{cite journal |vauthors=Watanabe F, Yabuta Y, Bito T, Teng F |title=Vitamin B₁₂-containing plant food sources for vegetarians |journal=Nutrients |volume=6 |issue=5 |pages=1861–73 |date=May 2014 |pmid=24803097 |pmc=4042564 |doi=10.3390/nu6051861 |quote="A nutritional analysis of six vegan children who had consumed vegan diets including brown rice and dried purple laver (nori) for 4–10 years suggested that the consumption of nori may prevent Vitamin B12 deficiency in vegans."|doi-access=free }}</ref> In the view of the Academy of Nutrition and Dietetics, however, it may not provide an adequate source of B12 for vegans.<ref name=MelinaCraig2016>{{cite journal| vauthors=Melina V, Craig W, Levin S| title=Position of the Academy of Nutrition and Dietetics: Vegetarian Diets |journal=J Acad Nutr Diet|year= 2016|volume= 116|issue= 12|pages= 1970–1980|pmid=27886704|doi=10.1016/j.jand.2016.09.025| s2cid=4984228 |quote=Fermented foods (such as tempeh), nori, spirulina, chlorella algae, and unfortified nutritional yeast cannot be relied upon as adequate or practical sources of B-12.39,40 Vegans must regularly consume reliable sources— meaning B-12 fortified foods or B-12 containing supplements—or they could become deficient, as shown in case studies of vegan infants, children, and adults.}}</ref>

==Species== ''Porphyra'' currently contains 57 confirmed species and 14 unconfirmed species.<ref name=WORMS1>{{cite WoRMS |author=Michael D. Guiry |year= 2024|title= ''Porphyra'' C.Agardh, 1824|id= 143808|accessdate=17 April 2024}}</ref> ===Confirmed=== {{Columns-list|colwidth=35em| *''Porphyra abbottae'' V.Krishnamurthy, 1972 (often treated as Pyropia abbottiae) *''Porphyra akasakae'' A.Miura, 1977 *''Porphyra angusta'' Okamura & Ueda, 1932 *''Porphyra argentinensis'' M.L.Piriz, 1981 *''Porphyra atropurpurea'' (Olivi) De Toni, 1897 *''Porphyra augustinae'' Kützing, 1843 *''Porphyra autumnalis'' Zanardini, 1860 *''Porphyra bulbopes'' (Yendo) Ueda, 1932 *''Porphyra capensis'' Kützing, 1843 *''Porphyra ceylanica'' J.Agardh, 1883 *''Porphyra chauhanii'' C.Anil Kumar & M.V.N.Panikkar, 1995 *''Porphyra coccinea'' J.Agardh *''Porphyra corallicola'' H.Kucera & G.W. Saunders, 2012 *''Porphyra delicatula'' Welwitsch *''Porphyra dentimarginata'' Chu Chia-yen & Wang Su-chuan, 1960 *''Porphyra dioica'' J.Brodie & L.M.Irvine, 1997 *''Porphyra fujianensis'' Zhang & Wang, 1993 *''Porphyra grateloupicola'' P.L.Crouan & H.M.Crouan, 1878 *''Porphyra guangdongensis'' C.K.Tseng & T.J.Chang, 1978 *''Porphyra inaequicrassa'' Perestenko, 1980 *''Porphyra indica'' V.Krishnamurthy & M.Baluswami, 1984 *''Porphyra ionae'' R.W.Ricker, 1987 *''Porphyra irregularis'' E.Fukuhara, 1968 *''Porphyra kanyakumariensis'' V.Krishnamurthy & M.Baluswami, 1984 *''Porphyra ledermannii'' Pilger, 1911 *''Porphyra linearis'' Greville, 1830 *''Porphyra longissima'' A.Meynard, M.E.Ramírez & L.Contreras-Porcia, 2018 *''Porphyra lucasii'' Levring, 1953 *''Porphyra luchea'' A.Meynard, M.E.Ramírez & L.Contreras-Porcia, 2018 *''Porphyra malvanensis'' Anilkumar & P.S.N.Rao, 2005 *''Porphyra marcosii'' P.A.Cordero, 1976 *''Porphyra marginata'' C.K.Tseng & T.J.Chang, 1958 *''Porphyra microphylla'' Zanardini, 1860 *''Porphyra monosporangia'' S.Wang & J.Zhang, 1980 *''Porphyra mumfordii'' S.C.Lindstrom & K.M.Cole, 1992 *''Porphyra njordii'' P.M.Pedersen, 2011 *''Porphyra ochotensis'' Nagai, 1941 *''Porphyra okamurae'' Ueda, 1932 *''Porphyra okhaensis'' H.V.Joshi, R.M.Oza & A.Tewari, 1992 *''Porphyra oligospermatangia'' C.K.Tseng & B.F.Zheng, 1981 *''Porphyra plocamiestris'' R.W.Ricker, 1987 *''Porphyra pujalsiae'' Coll & E.C.Oliveira, 1976 *''Porphyra punctata'' Y.Yamada & H.Mikami, 1956 *''Porphyra purpurea'' (Roth) C.Agardh, 1824 *''Porphyra qingdaoensi'' C.K.Tseng & B.F.Zheng, 1988 *''Porphyra ramosissima'' Pan & Wang, 1982 *''Porphyra rizzinii'' Coll & E.C.Oliveira, 1976 *''Porphyra roseana'' M.Howe, 1928 *''Porphyra schistothallus'' B.F.Zheng & J.Li *''Porphyra segregata'' (Setchell & Hus) V.Krishnamurthy, 1972 *''Porphyra subtumens'' J.Agardh *''Porphyra tanakae'' Pham Hoang-Ho, 1985 *''Porphyra tenuis'' B.F.Zheng & J.Li *''Porphyra tristanensis'' Baardseth, 1941 *''Porphyra umbilicalis'' Kützing, 1843 *''Porphyra violacea'' J.Agardh, 1899 *''Porphyra vulgaris'' Kützing, 1843 *''Porphyra woolhouseae'' Harvey, 1863 }}

===Unconfirmed=== {{Columns-list|colwidth=35em| *''Porphyra carnea'' Grunow, 1889 *''Porphyra cordata'' Meneghini, 1844 *''Porphyra cucullata'' De Notaris, 1865 *''Porphyra grayana'' Reinsch, 1875 *''Porphyra hospitans'' Zanardini, 1855 *''Porphyra livida'' De Notaris, 1846 *''Porphyra microphylla'' Reinsch, 1878 *''Porphyra minor'' Zanardini, 1847 *''Porphyra nobilis'' De Notaris, 1846 or J.Agardh, 1883 *''Porphyra reniformis'' Meneghini, 1849 *''Porphyra sericea'' (Wulfen) J.Agardh, 1883 *''Porphyra subtumens'' J.Agardh ex R.M.Laing, 1928 *''Porphyra tenuissima'' C.Agardh ex Frauenfeld, 1855 }} Following a major reassessment of the genus in 2011, many species previously included in ''Porphyra'' have been transferred to ''Pyropia'': for example ''Pyropia tenera'', ''Pyropia yezoensis'', and the species from New Zealand ''Pyropia rakiura'' and ''Pyropia virididentata'', leaving only five species out of seventy still within ''Porphyra'' itself.<ref>{{cite journal|author=Sutherland|title=A New Look at an Ancient Order: Generic Revision of the Bangiales (Rhodophyta)|journal=J. Phycol.|date=October 2011|volume=47|issue=5|pages=1131–1151|doi=10.1111/j.1529-8817.2011.01052.x|pmid=27020195|s2cid=2779596|display-authors=etal}}</ref>

== See also == * Green laver

==References== {{Reflist|2}}

==External links== * {{Commons category-inline|Porphyra|''Porphyra''}} * {{Wikispecies-inline|Porphyra|''Porphyra''}} * [https://www.youtube.com/watch?v=4DxnL1DwA6w Video footage of Laverbread or Bara Lawr]

Category:Red algae genera Category:Bangiophyceae Category:Edible seaweeds Category:Seaweeds Category:Edible algae Category:Taxa named by Carl Adolph Agardh