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.
Archaebacteria are organized into three phylums. They are found mainly found in extreme habitats where little else can survive. All Archaebacteria that are known are anerobic and obtain their energy from light. Methanogens: This type of bacteria produces methane.Many such species live in the intestines of animals.They provide essentail nutrients and help breakdown the food in the intestines.The bacteria get a source of energy in return.ethanogens: This type of bacteria produces methane. Many such species live in the intestines of animals. They provide essentail nutrients and help breakdown the food in the intestines. The bacteria get a source of energy in return.