Ulva lactuca

Last updated

Ulva lactuca
Sea lettuce in Brofjorden 1 - cropped.jpg
Ulva lactuca in Brofjorden, Sweden
Ulva lactuca - Sowerby.jpg
Illustration of Ulva lactuca in English Botany (Sowerby, 1790-1814)
Scientific classification OOjs UI icon edit-ltr.svg
Clade: Viridiplantae
Division: Chlorophyta
Class: UTC clade
Order: Ulvales
Family: Ulvaceae
Genus: Ulva
Species:
U. lactuca
Binomial name
Ulva lactuca
L.
Synonyms
  • Ulva crassaV. J. Chapman, 1956

Ulva lactuca, also known by the common name sea lettuce, [1] is an edible green alga in the family Ulvaceae. It is the type species of the genus Ulva . A synonym is U. fenestrata, referring to its "windowed" or "holed" appearance, Despite the name, it is not a lettuce [2]

Contents

Description

Ulva lactuca is a thin flat green alga growing from a discoid holdfast. The margin is somewhat ruffled and often torn. It may reach 18 centimetres (7.1 in) or more in length, though generally much less, and up to 30 centimetres (12 in) across. [3] The membrane is two cells thick, soft and translucent, and grows attached, without a stipe, to rocks or other algae by a small disc-shaped holdfast. [4]

Green to dark green in colour, this species in the Chlorophyta is formed of two layers of cells irregularly arranged, as seen in cross-section. The chloroplast is cup-shaped in some references but as a parietal plate in others [4] with one to three pyrenoids. There are other species of Ulva which are similar and not always easy to differentiate.

Distribution

The distribution is worldwide: Europe, North America (west and east coasts), Central America, Caribbean Islands, South America, Africa, Indian Ocean Islands, South-west Asia, China, Pacific Islands, Australia and New Zealand. [4] [5]

Ecology

Ulva lactuca is very common on rocks and on other algae in the littoral and sublittoral on shores all around the British Isles, [6] the coast of France, [7] the Low Countries [7] and up to Denmark. [8] It is particularly prolific in areas where nutrients are abundant. [9] This has been the case off the coast of Brittany where a high level of nitrates, from the intensive farming there, washes out to sea. [10] [11] The result is that large quantities of Ulva lactuca are washed up on beaches, where their decay produces methane, hydrogen sulfide, and other gases. [10] [12]

Certain environmental conditions can lead to the algae spreading over large areas. In August 2009, unprecedented levels of the algae washed up on the beaches of Brittany, France, [13] [14] causing a major public health scare as it decomposed. The rotting thalli produced large quantities of hydrogen sulfide, a toxic gas which, like hydrogen cyanide, inhibits cytochrome c oxidase, inhibiting cellular respiration and resulting in critical cellular hypoxia. In one incident near Saint-Michel-en-Grève, a horse rider lost consciousness and his horse died after breathing the seaweed fumes. Environmentalists blamed the phenomenon on excessive use of fertilizers and the excretion of nitrates by pig and poultry farmers. [13] In an earlier separate incident at the same beach in July 2009, a truck driver had died near his vehicle after hauling three truckloads of sea lettuce without protective gear during the annual cleanup. Although initially recorded as a heart attack, the death of the truck driver prompted French authorities to exhume his remains for an autopsy. It was later determined to be cardiac arrest resulting from pulmonary edema, which is an indication of possible hydrogen sulfide poisoning. [11] [15] Dead animals found on the algae-clogged beaches (including thirty-one wild boars in July 2011) were also claimed to be linked to toxic fumes by environmentalists. [16] [17]

Life history

The sporangial and gametangial thalli are morphologically alike. The diploid adult plant produces zoospores by meiosis – making them haploid. These settle and grow to form haploid male and female plants similar to the diploid plants. When these haploid plants release gametes they unite to produce the zygote which germinates, and grows to produce the diploid plant. [18] [19] [20]

Uses

U. lactuca is locally used in Scotland in soups and salads. [21] [22] In Hawaiʻi, U. lactuca is also called limu pālahala and eaten in different ways: mixed with other algae, salted and served with raw fish, boiled in water and served as a soup, or served with chili pepper, onions, soy sauce and sugar. [23] Additionally, U. lactuca has traditional uses in Hawaiʻi as fertilizer and as adornment for hula. [23] When U. lactuca is used for hula it is called limu pāpahapaha. [23]

Related Research Articles

<i>Chondrus crispus</i> Species of edible alga

Chondrus crispus—commonly called Irish moss or carrageenan moss —is a species of red algae which grows abundantly along the rocky parts of the Atlantic coasts of Europe and North America. In its fresh condition it is soft and cartilaginous, varying in color from a greenish-yellow, through red, to a dark purple or purplish-brown. The principal constituent is a mucilaginous body, made of the polysaccharide carrageenan, which constitutes 55% of its dry weight. The organism also consists of nearly 10% dry weight protein and about 15% dry weight mineral matter, and is rich in iodine and sulfur. When softened in water it has a sea-like odour. Because of the abundant cell wall polysaccharides, it will form a jelly when boiled, containing from 20 to 100 times its weight of water.

<span class="mw-page-title-main">Alternation of generations</span> Reproductive cycle of plants and algae

Alternation of generations is the predominant type of life cycle in plants and algae. In plants both phases are multicellular: the haploid sexual phase – the gametophyte – alternates with a diploid asexual phase – the sporophyte.

<i>Fucus vesiculosus</i> Species of Phaeophyceae

Fucus vesiculosus, known by the common names bladderwrack, black tang, rockweed, sea grapes, bladder fucus, sea oak, cut weed, dyers fucus, red fucus and rock wrack, is a seaweed found on the coasts of the North Sea, the western Baltic Sea and the Atlantic and Pacific Oceans. It was the original source of iodine, discovered in 1811, and was used extensively to treat goitre, a swelling of the thyroid gland related to iodine deficiency.

<span class="mw-page-title-main">Sea lettuce</span> Genus of seaweeds

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.

<i>Fucus</i> Genus of brown algae

Fucus is a genus of brown algae found in the intertidal zones of rocky seashores almost throughout the world.

<i>Palmaria palmata</i> Species of edible alga

Palmaria palmata, also called dulse, dillisk or dilsk, red dulse, sea lettuce flakes, or creathnach, is a red alga (Rhodophyta) previously referred to as Rhodymenia palmata. It grows on the northern coasts of the Atlantic and Pacific Oceans. It is a well-known snack food. In Iceland, where it is known as söl, it has been an important source of dietary fiber throughout the centuries.

<i>Alaria esculenta</i> Edible seaweed

Alaria esculenta is an edible seaweed, also known as dabberlocks or badderlocks, or winged kelp, and occasionally as Atlantic Wakame. It is a traditional food along the coasts of the far north Atlantic Ocean. It may be eaten fresh or cooked in Greenland, Iceland, Scotland and Ireland. It is the only one of twelve species of Alaria to occur in both Ireland and in Great Britain.

<i>Fucus serratus</i> Species of Phaeophyceae

Fucus serratus is a seaweed of the north Atlantic Ocean, known as toothed wrack, serrated wrack, or saw rack.

<i>Polysiphonia</i> Genus of algae

Polysiphonia, known as red hair algae, is a genus of filamentous red algae with about 19 species on the coasts of the British Isles and about 200 species worldwide, including Crete in Greece, Antarctica and Greenland. Its members are known by a number of common names. It is in the order Ceramiales and family Rhodomelaceae.

<i>Umbraulva</i> Genus of algae

The genus Umbraulva, which is a green alga within the Ulvaceae family, was proposed by Bae and Lee in 2001. Three additional species, including U. kuaweuweu, which was subsequently transferred to another genus, have been added to the genus since it originally had the three species that were initially examined to form the genus. Umbraulva species grow upon hard substrates, and inhabit deep subtidal areas. Species within this genus are widely distributed, and have been identified in Asia, Europe, Hawaii, and New Zealand. The morphological traits of Umbraulva vary among species, but commonly, Umbraulva are macroscopic with olive green blades containing the photosynthetic pigment siphonaxanthin. The blades are flattened and ellipsoid in shape, or are narrow and oval shaped, with perforations and/or lobes present throughout the blade. As Umbraulva often appear very similar in morphology to closely related groups, the main manner in which Umbraulva was differentiated from related groups was through the divergence of ITS and partial SSU rDNA sequences from those of other Ulva species. Umbraulva is closely related to Ulva, which due to wide distributions, high carbohydrate levels, and a lack of lignin, is a good candidate for use in biofuel, bioremediation, carbon sequestration, and animal feed production.

<span class="mw-page-title-main">Saint-Michel-en-Grève</span> Commune in Brittany, France

Saint-Michel-en-Grève is a commune in the Côtes-d'Armor department of Brittany in northwestern France.

<span class="mw-page-title-main">Seaweed</span> Macroscopic marine algae

Seaweed, or macroalgae, refers to thousands of species of macroscopic, multicellular, marine algae. The term includes some types of Rhodophyta (red), Phaeophyta (brown) and Chlorophyta (green) macroalgae. Seaweed species such as kelps provide essential nursery habitat for fisheries and other marine species and thus protect food sources; other species, such as planktonic algae, play a vital role in capturing carbon and producing at least 50% of Earth's oxygen.

<i>Ulva intestinalis</i> Species of marine chlorophyte green alga

Ulva intestinalis is a green alga in the family Ulvaceae, known by the common names sea lettuce, green bait weed, gutweed, and grass kelp. Until they were reclassified by genetic work completed in the early 2000s, the tubular members of the sea lettuce genus Ulva were placed in the genus Enteromorpha.

<i>Fucus distichus</i> Species of alga

Fucus distichus or rockweed is a species of brown alga in the family Fucaceae to be found in the intertidal zones of rocky seashores in the Northern Hemisphere, mostly in rock pools.

<i>Ulva linza</i> Species of seaweed

Ulva linza is a green alga in the family Ulvaceae that can be found in British Isles.

<i>Jania</i> (alga) Genus of algae

Jania is a genus of red macroalgae with hard, calcareous, branching skeletons in the family Corallinaceae.

<i>Ulva prolifera</i> Species of alga

Ulva prolifera, also known as the branched string lettuce, is a species of seaweed algae in the family Ulvaceae that can be found worldwide.

<i>Ulva paschima</i> Species of seaweed

Ulva paschima is a green alga in the family Ulvaceae, a green seaweed endemic to the West Coast of India. The species was identified in 2014 based on molecular phylogenetics using ITS sequences as belonging to the “Paschima” clade.

References

  1. ↑ David Chapman (2008). Exploring the Cornish Coast. Penzance: Alison Hodge. p. 25. ISBN   9780906720561.
  2. ↑ Bates, Colin. "An introduction to the (macro) algae of British Columbia". Electronic Atlas of the Flora of British Columbia, University of British Columbia. Retrieved 29 July 2020.
  3. ↑ "Ulva lactuca". Gettysburg College . Retrieved December 28, 2007.
  4. 1 2 3 Burrows, E.M. (1991). Seaweeds of the British Isles. Vol. 2. London: Natural History Museum. ISBN   978-0-565-00981-6.
  5. ↑ "Ulva lactuca Linnaeus". AlgaeBase.
  6. ↑ Hardy, F.G.; Guiry, M.D. (2006). A Check-list and Atlas of the Seaweeds of Britain and Ireland. London: British Phycological Society. ISBN   978-3-906166-35-3.
  7. 1 2 "Tisbe taxon details: Ulva lactuca Linnaeus, 1753". Flanders Marine Institute (VLIZ).
  8. ↑ Geertz-Hansen, O.; Sand-Jensen, K.; Hansen, D. F.; Christiansen, A. (September 1993). "Growth and grazing control of abundance of the marine macroalga, Ulva lactuca L. in a eutrophic Danish estuary". Aquatic Botany . 46 (2): 101–109. doi:10.1016/0304-3770(93)90039-Y.
  9. ↑ Michael Guiry. "Overview of Ulva lactuca ecology". The Seaweed Site. Retrieved December 28, 2007.
  10. 1 2 Hirst, Michael (August 11, 2009). "Toxic seaweed clogs French coast". BBC News . Retrieved August 11, 2009.
  11. 1 2 "Seaweed suspected in French death". BBC News . September 7, 2009. Retrieved 2009-09-08.
  12. ↑ Nedergaard, Rasmus I.; Risgaard-Petersen, Nils; Finster, Kai (August 17, 2002). "The importance of sulfate reduction associated with Ulva lactuca thalli during decomposition: a mesocosm experiment". Journal of Experimental Marine Biology and Ecology . 275 (1): 15–29. doi:10.1016/S0022-0981(02)00211-3.
  13. 1 2 Hirst, Michael (2009-08-11). "Toxic seaweed clogs French coast". BBC . Retrieved 2009-08-11.
  14. ↑ Samuel, Henry (2009-08-11). "Almost 100 places in Brittany have toxic seaweed". Telegraph.co.uk . Retrieved 2009-08-11.
  15. ↑ Lymbery, Philip (2014). Farmageddon: The True Cost of Cheap Meat. Bloomsbury Publishing. p. 179. ISBN   9781408846421.
  16. ↑ Chrisafis, Angelique. "Brittany beaches hit by toxic algae". The Guardian. No. 27 July 2011. Retrieved 31 December 2015.
  17. ↑ McKenna, Maryn (26 July 2011). "Attack of the Deadly Slime: Farm Effluent Ruins French Beaches". Wired. Retrieved 31 December 2015.
  18. ↑ Abbott, I.A. & Hollenberg, G.J. (1976). Marine Algae of California.. California: Stanford University Press. ISBN   978-0-8047-0867-8.
  19. ↑ Mondragon, J. & Mondragon, J. (2003). Seaweeds of the Pacific Coast.. Monterey, California: Sea Challengers. ISBN   978-0-930118-29-7.
  20. ↑ " "Plant Science 4 U" . Retrieved 5 July 2016.
  21. ↑ Indergaad, M and Minsaas, J. 1991 in Guiry, M.D. and Blunden, G. 1991. Seaweed Resources in Europe: Uses and Potential. John Wiley & Sons ISBN   0 471 92947 6
  22. ↑ "Ulva Recipes". Monterey Bay Aquarium Research Institute. Archived from the original on January 2, 2008. Retrieved December 28, 2007.
  23. 1 2 3 Aiona., Abbott, Isabella (1996). Limu : an ethnobotanical study of some Hawaiian seaweeds. National Tropical Botanical Garden. OCLC   34798092.{{cite book}}: CS1 maint: multiple names: authors list (link)

Further reading

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.