Emiliania huxleyi

Taxobox
name = "Emiliania huxleyi"


image_width = 250px
image_caption = "Emiliania huxleyi"
domain = Eukaryota
regnum = Chromalveolata
phylum = Haptophyta
classis = Prymnesiophyceae
ordo = Isochrysidales
familia = Noelaerhabdaceae
genus = "Emiliania"
species = "E. huxleyi"
binomial = "Emiliania huxleyi"
binomial_authority = (Lohm.) Hay and Mohler

"Emiliania huxleyi", often abbreviated to simply "EHUX", is a species of coccolithophore with a global distribution from the tropics to subarctic waters. It is studied for the extensive blooms it forms in nutrient depleted waters after the reformation of the summer thermocline. Like other coccolithophores, "E. huxleyi" is a single-celled phytoplankton covered with uniquely ornamented calcite disks, coccoliths (also informally known as liths or scales). Individual coccoliths are abundant in marine sediments although complete coccospheres are more unusual. In the case of "E. huxleyi", not only the shell, but also the soft part of the organism may be recorded in sediments. It produces a group of chemical compounds that are very resistant to decomposition. These chemical compounds, known as alkenones, can be found in marine sediments long after other soft parts of the organisms have decomposed. Alkenones are used by earth scientists as a clue to past sea surface temperatures.

Named after Thomas Huxley, it is the most numerically abundant and widespread coccolithophore species. Its coccoliths are transparent and colourless, but they are formed of calcite which refracts light very efficiently in the water column. This, and the high concentrations caused by continual shedding of their coccoliths makes "E. huxleyi" blooms easily visible from space. Satellite images show that blooms can cover large areas (possibly >100,000 square kilometers), with complementary shipboard measurements indicating that "E. huxleyi" is by far the dominant phytoplankton species under these conditions.

This species has been the inspiration for James Lovelock's Gaia hypothesis which claims that living organisms somehow may be able to self regulate their own conditions of chemistry and climate at a state favourable for life.

References

* [http://bioinfo.csusm.edu Cocco Express - Coccolithophorids Expressed Sequence Tags (EST) & Microarray Database]
* [http://www.noc.soton.ac.uk/soes/staff/tt/eh/ "Emiliania huxleyi" Home Page]

ee also

* Ocean acidification
* Emiliania huxleyi virus 86 a giant marine virus that infects "Emiliania huxleyi"