Brine shrimp

Taxobox
name = Brine shrimp

---

image_caption = "Artemia salina"
regnum = Animalia
phylum = Arthropoda
subphylum = Crustacea
classis = Branchiopoda
ordo = Anostraca
familia = Artemiidae
familia_authority = Grochowski, 1895
genus = "Artemia"
genus_authority = Leach, 1819
subdivision_ranks = Species
subdivision = "Artemia franciscana"
"Artemia gracilis"
"Artemia monica"
"Artemia parartemia"
"Artemia parthenogenetica"
"Artemia persimilis"
"Artemia pollicaris"
"Artemia salina"
"Artemia salina x nyos"
"Artemia sinica"
"Artemia tibetiana"
"Artemia tunesiana"
"Artemia urmiana"

Brine shrimp are a species of aquatic crustaceans of the genus "Artemia". "Artemia", the only genus in the family Artemiidae, have evolved little since the Triassic period. First discovered in Lymington, England, in 1755, [ cite journal|title=SALTY SURVIVORS: Artemia: Basic and Applied Biology|journal= [http://jeb.biologists.org/ J Exp Biol] |date=2004|first=Brian D.|last=Eads|coauthors=|volume=207|issue=11|pages=1757–8|doi= 10.1242/jeb.01005|url=http://jeb.biologists.org/cgi/content/full/207/11/1757|format=|accessdate=2008-03-20 ] "Artemia" are found worldwide in inland saltwater lakes, but not in oceans.

"Artemia" is a well known genus as one variety (sometimes identified as a new species "Artemia salina x nyos"), a cultivated subspecies of "Artemia salina", is sold as a novelty gift, most often under the marketing name Sea-Monkeys.

Life cycle

Brine shrimp eggs are metabolically inactive and can remain in total stasis for several years while in dry oxygen-free conditions, even at temperatures below freezing. This characteristic is called "cryptobiosis" meaning "hidden life" (also called "diapause"). Once placed in water, the cyst-like eggs hatch within a few hours. The nauplii, or larvae, are less than 0.5mm in length when they first hatch. Brine shrimp have a biological life cycle of one year, during which they grow to a mature length of around one cm on average. This short life span, along other characteristics such as their ability to remain dormant for long periods, has made them invaluable in scientific research, including space experiments.

Diet

Brine shrimp eat micro-algae, but will also eat yeast, wheat flour, soybean powder, or egg yolk. [ cite web|url=http://web.cecs.pdx.edu/~davidr/discus/articles/artemia.html |title=Artemia (Brine Shrimp) FAQ 1.1 |accessdate=2008-03-20 |last=Schumann |first=Kai |date=1997-08-10 |publisher=Portland State University |archiveurl=http://web.archive.org/web/20070814003850/http://web.cecs.pdx.edu/~davidr/discus/articles/artemia.html |archivedate=2007-08-14 ]

Tolerance to salinity

Brine shrimp can tolerate varying levels of salinity. A common biology experiment in school is to investigate the effect of salinity levels on the growth of these creatures.

Nutritional benefits

The nutritional properties of newly hatched brine shrimp make them particularly suitable to be sold as aquarium food as they are high in lipids and unsaturated fatty acids (but low in calcium). These nutritional benefits are likely to be one reason that brine shrimp are found only in highly salinated waters with reasonable temperatures. This makes sense as these areas are uninhabitable for potential predators.

'Threatened'

"Artemia monica", the variety commonly known as Mono Lake brine shrimp, are found only in Mono Lake, Mono County, California. In 1987, Dr. Dennis D. Murphy from Stanford University petitioned the United States Fish and Wildlife Service to add "Artemia monica" to the endangered species list under the Endangered Species Act 1973. Despite there being trillions of these creatures in Mono Lake, it was felt that rising levels of salinity and sodium hydroxide concentration of the lake would endanger them because of the increase in pH. However, the US Fish and Wildlife Service reported in the "Federal Register" on 7 September 1995 that this brine shrimp did not warrant listing after the threat to the lake was removed following a revised policy by the California State Water Resources Control Board. [cite journal |quotes=no |url=http://frwebgate3.access.gpo.gov/cgi-bin/waisgate.cgi?WAISdocID=9913285177+1+0+0&WAISaction=retrieve |title=Endangered and Threatened Wildlife and Plants; 12-Month Finding for a Petition to List the Mono Lake Brine Shrimp as Endangered |author=United States Fish and Wildlife Service |journal=Federal Register |volume=60 |issue=173 |year=1995 |pages=46571–46572]

References

Bibliography

* "Salty Survivors: Artemia: Basic and Applied Biology", Edited by Th. J. Abatzopoulos, J. A. Beardmore, J. S. Clegg and P. Sorgeloos , Kluwer Academic Publishers (2002). ISBN 1402007469

External links

* http://sn2000.taxonomy.nl/Taxonomicon/TaxonTree.aspx?id=33062 "Genus "Artemia", "The Taxonomicon & Systema Naturae 2000"
* http://web.archive.org/web/20060423082302/http://www.lander.edu/rsfox/310artemiaLab.html "Artemia franciscana" "Invertebrate Anatomy Online"
* http://ut.water.usgs.gov/shrimp/index.html "Brine Shrimp and Ecology of Great Salt Lake", United States Geological Survey