Sea lettuce

From Wikipedia, the free encyclopedia
Jump to: navigation, search
For other uses, see List of plants known as sea lettuce.
Sea lettuce
Ulva lactuca - Sowerby.jpg
Ulva lactuca
Illustration from Sowerby's English botany 1790-1814, by James Sowerby
Scientific classification
Domain: Eukarya
Kingdom: Plantae
Phylum: Chlorophyta
Class: Ulvophyceae
Order: Ulvales
Family: Ulvaceae
Genus: Ulva
Linnaeus, 1753
Species

See text
Synonyms[1]
  • Enteromorpha Link in Nees, 1820

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,[1] the former members of which are known under the common name green nori.[2] Individual blades of Ulva can grow to be more than 400mm (16") in size, but this only occurs when the plants are growing in sheltered areas.

Genetics[edit]

There are some indications that this genus is of tropical in origin. In an extensive phylogeographical assessment of this genus conducted in India revealed a strong endemism, irrespective of thallus characteristics, viz., branched or unbranched. Previously, branched tubular Ulva was grouped under Ulva compressa, and unbranched under Ulva intestinalis. As per uniqueness of OTUs, a new endemic species irrespective of the thallus branching characteristics had been formally established as Ulva paschima Bast.[3] In tropics, diversity of Ulva is so much higher than that in temperate or sub-polar regions.

Nutrition[edit]

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.[citation needed]

Aquarium Trade[edit]

Sea lettuce is a commonly found species of algae in the saltwater aquarium trade, where it is valued for its high nutrient uptake and edibility. Many reef aquarium keepers use sea lettuce species in refugiums 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[edit]

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.[4] Environmentalists blamed the phenomenon on excessive use of nitrates by pig and poultry farmers.

Species[edit]

Species in the genus Ulva include the following:[5]

Accepted species
Nomina dubia

See also[edit]

Wikimedia Commons has media related to Ulva.
Wikimedia Commons has media related to Ulva (genus).

References[edit]

  1. ^ a b Hillary S. Hayden, Jaanika Blomster, Christine A. Maggs, Paul C. Silva, Michael J. Stanhope, & J. Robert Waaland (2003). "Linnaeus was right all along: Ulva and Enteromorpha are not distinct genera" (PDF). European Journal of Phycology (British Phycological Society) 38: 277–294. doi:10.1080/1364253031000136321. ISSN 1469-4433. 
  2. ^ M.D. Guiry & G.M. Guiry (2012). "Enteromorpha Link in Nees, 1820". AlgaeBase. National University of Ireland. Retrieved February 11, 2012. 
  3. ^ 1. BAST, F., JOHN, A.A. AND BHUSHAN, S. 2014. Strong endemism of bloom-forming tubular Ulva in Indian west coast, with description of Ulva paschima Sp. Nov. (Ulvales, Chlorophyta. PLoS ONE 9(10): e109295. doi:10.1371/journal.pone.0109295
  4. ^ "Seaweed suspected in French death". BBC. September 7, 2009. Retrieved September 7, 2009. 
  5. ^ M.D. Guiry (2012). M. D. Guiry & G. M. Guiry, ed. "Ulva Linnaeus, 1753". AlgaeBase. National University of Ireland, Galway. World Register of Marine Species. Retrieved February 11, 2012. 

External links[edit]

Retrieved from "http://en.wikipedia.org/w/index.php?title=Sea_lettuce&oldid=639776226"