the hard, variously colored, calcareous skeleton secreted by certain marine polyps. 2. such skeletons collectively, forming reefs, islands, etc. 3. the solitary or colonial polyp that secretes this calcareous skeleton.
There are three major known groups of Archaebacteria: methanogens, halophiles, and thermophiles. The methanogens are anaerobic bacteria that produce methane. They are found in sewage treatment plants, bogs, and the intestinal tracts of ruminants.
An example of a Euryarchaeota is Halobacterium which includes several species of organisms that are found in salt lakes and high saline ocean environments. Korachaeota. This is the name given to the Archaebacteria that do not fall under the Crenarchaeota or Euryarchaeota phyla.ver 250 known species of archaea exist, all of which have been classified into three main phyla (Ramel, n.d.) : 1. Crenarchaeota. 2. Euryarchaeota. 3. Korarchaeota. Crenarchaeota. The members of this phylum are known to be extremophiles.