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.
Euryarchaeota Species: Examples of Euryarchaeotans include: 1  Halobacterium-include several species of halophilic organisms that are found in salt lakes and high saline ocean environments. 2  Methanococcus-Methanococcus jannaschii was the first genetically sequenced Archaean.