What is "haloarchaea"

In taxonomy, the Halobacteria (also Halobacteriacea) are a class of the Euryarchaeota, found in water saturated or nearly saturated with salt. Halobacteria are now recognized as archaea, rather than bacteria. The name 'halobacteria' was assigned to this group of organisms before the existence of the domain Archaea was realized, and remains valid according to taxonomic rules. In a non-taxonomic context, halophilic archaea are referred to as haloarchaea to distinguish them from halophilic bacteria.

These microorganisms are members of the halophile community, in that they require high salt concentrations to grow. They are a distinct evolutionary branch of the Archaea, and are generally considered extremophiles, although not all members of this group can be considered as such.

Haloarchaea can grow aerobically or anaerobically. Parts of the membranes of haloarchaea are purplish in color, and large blooms of haloarchaea appear reddish, from the pigment bacteriorhodopsin, related to the retinal pigment rhodopsin which it uses to transform light energy into chemical energy by a process unrelated to chlorophyll-based photosynthesis.