Emiliania huxleyi

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Emiliania huxleyi

Emiliania huxleyi

Scientific classification

Domain:	Eukaryota
(unranked)	Chromista
Phylum:	Haptophyta
Class:	Prymnesiophyceae
Order:	Isochrysidales
Family:	Noelaerhabdaceae
Genus:	Emiliania
Species:	E. huxleyi

Binomial name

Emiliania huxleyi
(Hay & Mohler in Hay, Mohler, Roth,
Schmidt & Boudreaux, 1967)

Emiliania huxleyi, often abbreviated to simply "EHUX", is a species of coccolithophore, single-celled phytoplankton that are covered with uniquely ornamented calcite disks (also known as liths or scales). Individual plates are common in marine sediments although complete specimens are more unusual. In the case of E. huxleyi, not only the shell, but 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 globally most significant coccolithophore. 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.