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.
Ancient methanogens are the source of natural gas. Halophiles are bacteria that thrive in high salt concentrations such as those found in salt lakes or pools of sea water. Thermophiles are the heat-loving bacteria found near hydrothermal vents and hot springs.
The first type is called Methanogens. 1  This type of Archaebacteria live in oxegen free enviornments and they produce Methane gasess. 2  Places methangogens can be found are: marshes, lake sediments, and digestive tracts of animals. 3  Commercial use: used in sewage plant to help breakdown sewage.