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.
Archaebacteria are a type of prokaryote, that is, a unicellular organism without a cell nucleus. They make up the kingdom Archae, one of the main kingdoms of life.These organisms are difficult to classify because they have similarities to both normal bacteria and the larger eukaryotes.ut they differ from the cell wall and the cell membrane. In prokaryotic cell membrane a phospholipid bi layer is present. But in archaebacteria a single layer of phospholipid is available. That's a reason why they could live in very limited resource environments.