Emiliania huxleyi

Emiliania huxleyi
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Emiliania_huxleyi".

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Emiliania huxleyi

Scientific classification

Domain:	Eukaryota
Kingdom:	Chromalveolata
Phylum:	Haptophyta
Class:	Prymnesiophyceae
Order:	Isochrysidales
Family:	Noelaerhabdaceae
Genus:	Emiliania
Species:	E. huxleyi

Binomial name

Emiliania huxleyi
(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.

Landsat image from 24th July 1999 of a Emiliania huxleyi bloom

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.

References

See also