Ulva (genus)

The sea lettuces comprise the genus ''Ulva'', a group of edible green algae that is 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'', the former members of 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. However, contamination with toxic heavy metals at certain sites where it can be collected makes it dangerous for human consumption.

Aquarium trade

Sea lettuce species are commonly found in the saltwater aquarium trade, where the plants are valued for their high nutrient uptake and edibility. Many reef aquarium keepers use sea lettuce species in refugia or grow it as a food source for herbivorous fish. Sea lettuce is very easy to keep, tolerating a wide range of lighting and temperature conditions. In the refugium, sea lettuce can be attached to live rock or another surface, or simply left to drift in the water.

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 animal waste from industrial farms.

Species

Species in the genus ''Ulva'' include:

;Accepted species

*''Ulva acanthophora'' (Kützing) Hayden, Blomster, Maggs, P.C. Silva, Stanhope & J.R. Waaland, 2003
*''Ulva anandii'' Amjad & Shameel, 1993
*'' Ulva arasakii'' Chihara, 1969
*'' Ulva atroviridis'' Levring, 1938
*'' Ulva australis'' Areschoug, 1854
*'' Ulva beytensis'' Thivy & Sharma, 1966
*'' Ulva bifrons'' Ardré, 1967
*'' Ulva brevistipita'' V.J. Chapman, 1956
*'' Ulva burmanica'' (Zeller) De Toni, 1889
*'' Ulva californica'' Wille, 1899
*'' Ulva chaetomorphoides'' (Børgesen) Hayden, Blomster, Maggs, P.C. Silva, M.J. Stanhope & J.R. Waaland, 2003
*'' Ulva clathrata'' (Roth) C. Agardh, 1811
*'' Ulva compressa'' Linnaeus, 1753
*'' Ulva conglobata'' Kjellman, 1897
*'' Ulva cornuta'' Lightfoot, 1777
*'' Ulva covelongensis'' V. Krishnamurthy & H. Joshi, 1969
*''Ulva crassa'' V.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 denticulata'' P.J.L. Dangeard, 1959
*'' Ulva diaphana'' Hudson, 1778
*''Ulva elegans'' Gayral, 1960
*'' Ulva enteromorpha'' Le Jolis, 1863
*'' Ulva erecta'' ( Lyngbye) Fries
*''Ulva expansa'' (Setchell) Setchell & N.L. Gardner, 1920
*'' Ulva fasciata'' Delile, 1813
*'' Ulva flexuosa'' Wulfen, 1803
*'' Ulva geminoidea'' V.J. Chapman, 1956
*'' Ulva gigantea'' (Kützing) Bliding, 1969
*'' Ulva grandis'' Saifullah & 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 indica'' Roth, 1806
*'' Ulva intestinalis'' Linnaeus, 1753
*'' Ulva intestinaloides'' (R.P.T. Koeman & Hoek) Hayden, Blomster, Maggs, P.C. Silva, M.J. Stanhope & J.R. Waaland, 2003
*'' Ulva javanica'' N.L. Burman, 1768
*'' Ulva kylinii'' (Bliding) Hayden, Blomster, Maggs, P.C. Silva, M.J. Stanhope & J.R. Waaland, 2003
*''Ulva lactuca'' Linnaeus, 1753
*'' Ulva laetevirens'' J.E. Areschoug, 1854
*'' Ulva laingii'' V.J. Chapman, 1956
*'' Ulva linearis'' P.J.L. Dangeard, 1957
*'' Ulva linza'' Linnaeus, 1753
*'' Ulva lippii'' Lamouroux
*'' Ulva litoralis'' Suhr ex Kützing
*'' Ulva littorea'' Suhr
*'' Ulva lobata'' (Kützing) Harvey, 1855
*'' Ulva marginata'' (J. Agardh) Le Jolis
*'' Ulva micrococca'' (Kützing) Gobi
*'' Ulva mutabilis'' Föyn, 1958
*'' Ulva neapolitana'' Bliding, 1960
*'' Ulva nematoidea'' Bory de Saint-Vincent, 1828
*'' Ulva ohnoi'' Hiraoka & Shimada, 2004
*'' Ulva olivascens'' P.J.L. Dangeard
*'' Ulva pacifica'' Endlicher
*'' Ulva papenfussii'' Pham-Hoang Hô, 1969
*'' Ulva parva'' V.J. Chapman, 1956
*'' Ulva paschima'' Bast
*'' Ulva patengensis'' Salam & Khan, 1981
*'' Ulva percursa'' (C. Agardh) C. Agardh
*''Ulva pertusa'' Kjellman, 1897
*'' Ulva phyllosa'' (V.J. Chapman) Papenfuss
*'' Ulva polyclada'' Kraft, 2007
*'' Ulva popenguinensis'' P.J.L. Dangeard, 1958
*'' Ulva porrifolia'' (S.G. Gmelin) J.F. Gmelin
*'' Ulva profunda'' W.R. Taylor, 1928
*''Ulva prolifera'' O.F.Müller, 1778
*'' Ulva pseudocurvata'' Koeman & Hoek, 1981
*'' Ulva pseudolinza'' (R.P.T. Koeman & Hoek) Hayden, Blomster, Maggs, P.C. Silva, M.J. Stanhope & J.R. Waaland, 2003
*'' Ulva pulchra'' Jaasund, 1976
*'' Ulva quilonensis'' Sindhu & 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 ranunculata'' Kraft & A.J.K. Millar, 2000
*''Ulva reticulata'' Forsskål, 1775
*'' Ulva rhacodes'' (Holmes) Papenfuss, 1960
*'' Ulva rigida'' C. Agardh, 1823
*'' Ulva rotundata'' Bliding, 1968
*'' Ulva saifullahii'' Amjad & Shameel, 1993
*'' Ulva serrata'' A.P.de Candolle
*'' Ulva simplex'' (K.L. Vinogradova) Hayden, Blomster, Maggs, P.C. Silva, M.J. Stanhope & J.R. Waaland, 2003
*'' Ulva sorensenii'' V.J. Chapman, 1956
*'' Ulva spinulosa'' Okamura & Segawa, 1936
*'' Ulva stenophylla'' Setchell & N.L. Gardner, 1920
*'' Ulva sublittoralis'' Segawa, 1938
*'' Ulva subulata'' (Wulfen) Naccari
*'' Ulva taeniata'' (Setchell) Setchell & N.L. Gardner, 1920
*'' Ulva tanneri'' H.S. Hayden & J.R. Waaland, 2003
*'' Ulva tenera'' Kornmann & Sahling
*'' Ulva torta'' (Mertens) Trevisan, 1841
*'' Ulva tuberosa'' Palisot de Beauvois
*'' Ulva uncialis'' (Kützing) Montagne, 1850
*'' Ulva uncinata'' Mohr
*'' Ulva uncinata'' Mertens
*'' Ulva usneoides'' Bonnemaison
*'' Ulva utricularis'' (Roth) C. Agardh
*'' Ulva utriculosa'' C. Agardh
*'' Ulva uvoides Bory'' de Saint-Vincent
*'' Ulva ventricosa'' A.P.de Candolle

;Nomina dubia
*'' Ulva costata'' Wollny, 1881
*'' Ulva repens'' Clemente, 1807
*'' Ulva tetragona'' A.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''. Lagourgue, L ''et al'' 2022 The new species of ''Ulva'' (Ulvophyceae, Chlorophyta) discovered in New Caledonia genetic and morphological and diversity, and bloom potential. ''British Phycological Society'' 57;458 - 478.

References

nissima,

External links

Marine botany: Ulva
*

Toxic seaweed clogs French coas Caledonia: morphological diversity, and blooom potential.t (BBC)

{{Authority control

Ulvaceae
Edible seaweeds
Edible algae
Taxa named by Carl Linnaeus