Ulva intestinalis

The sea lettuces comprise the genus Ulva, a group of edible green algae that are widely distributed along the coasts of the world's oceans. The type species within the genus Ulva is Ulva lactuca, lactuca being Latin for "lettuce". The genus also includes the species previously classified under the genus Enteromorpha, which are known under the common name green nori.

Description

Individual blades of Ulva can grow to be more than 400 mm (16 in) in size, but this occurs only when the plants are growing in sheltered areas. A macroscopic alga which is light to dark green in colour, it is attached by disc holdfast. Their structure is a leaflike flattened thallus.

Nutrition and contamination

Sea lettuce is eaten by a number of different sea animals, including manatees and the sea slugs known as sea hares.

Many species of sea lettuce are a food source for humans in Scandinavia, Great Britain, Ireland, China, and Japan (where this food is known as aosa). Sea lettuce as a food for humans is eaten raw in salads and cooked in soups. It is high in protein, soluble dietary fiber, and a variety of vitamins and minerals, especially iron. Enhances flavor and fortifies bread when chopped and mixed into the dough before baking.

Contamination with toxic heavy metals at certain sites where it can be collected makes it dangerous for human consumption.

Health concerns

In August 2009, unprecedented amounts of these algae washed up on the beaches of Brittany, France, causing a major public health scare as it decomposed. The rotting leaves produced large quantities of hydrogen sulfide, a toxic gas. In one incident near Saint-Michel-en-Grève, a horse rider lost consciousness and his horse died after breathing the seaweed fumes; in another, a lorry driver driving a load of decomposing sea lettuce passed out, crashed, and died, with toxic fumes claimed to be the cause. Environmentalists blamed the phenomenon on excessive nitrogenous compounds washed out to sea from improper disposal of pig and poultry slurry from industrial farms, and from chemical products and slurry used as fertilisers in arable farming.

Species

Species in the genus Ulva include:

Accepted species

  • Ulva acanthophora(Kützing) Hayden, Blomster, Maggs, P.C. Silva, Stanhope & J.R. Waaland, 2003
  • Ulva anandiiAmjad & Shameel, 1993
  • Ulva arasakiiChihara, 1969
  • Ulva atroviridisLevring, 1938
  • Ulva australis Areschoug, 1854
  • Ulva beytensisThivy & Sharma, 1966
  • Ulva bifronsArdré, 1967
  • Ulva brevistipitaV.J. Chapman, 1956
  • Ulva burmanica(Zeller) De Toni, 1889
  • Ulva californicaWille, 1899
  • Ulva chaetomorphoides(Børgesen) Hayden, Blomster, Maggs, P.C. Silva, M.J. Stanhope & J.R. Waaland, 2003
  • Ulva clathrata(Roth) C. Agardh, 1811
  • Ulva compressaLinnaeus, 1753
  • Ulva conglobataKjellman, 1897
  • Ulva cornutaLightfoot, 1777
  • Ulva covelongensisV. Krishnamurthy & H. Joshi, 1969
  • Ulva crassaV.J. Chapman, 1956
  • Ulva crassimembrana(V.J. Chapman) Hayden, Blomster, Maggs, P.C. Silva, M.J. Stanhope & J.R. Waaland, 2003
  • Ulva curvata(Kützing) De Toni, 1889
  • Ulva denticulataP.J.L. Dangeard, 1959
  • Ulva diaphanaHudson, 1778
  • Ulva elegansGayral, 1960
  • Ulva enteromorphaLe Jolis, 1863
  • Ulva erecta(Lyngbye) Fries
  • Ulva expansa(Setchell) Setchell & N.L. Gardner, 1920
  • Ulva fasciataDelile, 1813
  • Ulva flexuosaWulfen, 1803
  • Ulva geminoideaV.J. Chapman, 1956
  • Ulva gigantea(Kützing) Bliding, 1969
  • Ulva grandisSaifullah & Nizamuddin, 1977
  • Ulva hookeriana(Kützing) Hayden, Blomster, Maggs, P.C. Silva, M.J. Stanhope & J.R. Waaland
  • Ulva hopkirkii(M'Calla ex Harvey) P. Crouan & H. Crouan
  • Ulva howensis(A.H.S. Lucas) Kraft, 2007
  • Ulva indicaRoth, 1806
  • Ulva intestinalisLinnaeus, 1753
  • Ulva intestinaloides(R.P.T. Koeman & Hoek) Hayden, Blomster, Maggs, P.C. Silva, M.J. Stanhope & J.R. Waaland, 2003
  • Ulva javanicaN.L. Burman, 1768
  • Ulva kylinii(Bliding) Hayden, Blomster, Maggs, P.C. Silva, M.J. Stanhope & J.R. Waaland, 2003
  • Ulva lactucaLinnaeus, 1753
  • Ulva laetevirensJ.E. Areschoug, 1854
  • Ulva laingiiV.J. Chapman, 1956
  • Ulva linearisP.J.L. Dangeard, 1957
  • Ulva linzaLinnaeus, 1753
  • Ulva lippiiLamouroux
  • Ulva litoralisSuhr ex Kützing
  • Ulva littoreaSuhr
  • Ulva lobata(Kützing) Harvey, 1855
  • Ulva maeotica(Proshkina-Lavrenko) P.M.Tsarenko, 2011
  • Ulva marginata(J. Agardh) Le Jolis
  • Ulva micrococca(Kützing) Gobi
  • Ulva mutabilisFöyn, 1958
  • Ulva neapolitanaBliding, 1960
  • Ulva nematoideaBory de Saint-Vincent, 1828
  • Ulva ohnoiHiraoka & Shimada, 2004
  • Ulva olivascensP.J.L. Dangeard
  • Ulva pacificaEndlicher
  • Ulva papenfussiiPham-Hoang Hô, 1969
  • Ulva parvaV.J. Chapman, 1956
  • Ulva paschimaBast
  • Ulva patengensisSalam & Khan, 1981
  • Ulva percursa(C. Agardh) C. Agardh
  • Ulva pertusaKjellman, 1897
  • Ulva phyllosa(V.J. Chapman) Papenfuss
  • Ulva polycladaKraft, 2007
  • Ulva popenguinensisP.J.L. Dangeard, 1958
  • Ulva porrifolia(S.G. Gmelin) J.F. Gmelin
  • Ulva profundaW.R. Taylor, 1928
  • Ulva proliferaO.F.Müller, 1778
  • Ulva pseudocurvataKoeman & Hoek, 1981
  • Ulva pseudolinza(R.P.T. Koeman & Hoek) Hayden, Blomster, Maggs, P.C. Silva, M.J. Stanhope & J.R. Waaland, 2003
  • Ulva pulchraJaasund, 1976
  • Ulva quilonensisSindhu & Panikkar, 1995
  • Ulva radiata(J. Agardh) Hayden, Blomster, Maggs, P.C. Silva, M.J. Stanhope & J.R. Waaland, 2003
  • Ulva ralfsii(Harvey) Le Jolis, 1863
  • Ulva ranunculataKraft & A.J.K. Millar, 2000
  • Ulva reticulataForsskål, 1775
  • Ulva rhacodes(Holmes) Papenfuss, 1960
  • Ulva rigidaC. Agardh, 1823
  • Ulva rotundataBliding, 1968
  • Ulva saifullahiiAmjad & Shameel, 1993
  • Ulva serrataA.P.de Candolle
  • Ulva simplex(K.L. Vinogradova) Hayden, Blomster, Maggs, P.C. Silva, M.J. Stanhope & J.R. Waaland, 2003
  • Ulva sorenseniiV.J. Chapman, 1956
  • Ulva spinulosaOkamura & Segawa, 1936
  • Ulva stenophyllaSetchell & N.L. Gardner, 1920
  • Ulva sublittoralisSegawa, 1938
  • Ulva subulata(Wulfen) Naccari
  • Ulva taeniata(Setchell) Setchell & N.L. Gardner, 1920
  • Ulva tanneriH.S. Hayden & J.R. Waaland, 2003
  • Ulva teneraKornmann & Sahling
  • Ulva torta(Mertens) Trevisan, 1841
  • Ulva tuberosaPalisot de Beauvois
  • Ulva uncialis(Kützing) Montagne, 1850
  • Ulva uncinataMohr
  • Ulva uncinataMertens
  • Ulva usneoidesBonnemaison
  • Ulva utricularis(Roth) C. Agardh
  • Ulva utriculosaC. Agardh
  • Ulva uvoides Boryde Saint-Vincent
  • Ulva ventricosaA.P.de Candolle

Nomina dubia

  • Ulva costataWollny, 1881
  • Ulva repensClemente, 1807
  • Ulva tetragonaA.P.de Candolle, 1807

A newly discovered Indian endemic species of Ulva with tubular thallus indistinguishable from Ulva intestinalis has been formally established in 2014 as Ulva paschima Bast. Ten new species have been discovered in New Caledonia: Ulva arbuscula, Ulva planiramosa, Ulva batuffolosa, Ulva tentaculosa, Ulva finissima, Ulva pluriramosa, Ulva scolopendra and Ulva spumosa.

See also

Further reading

  • Beer, Sven (2023). . European Journal of Phycology. 58: 390–398. doi:.

External links