Type Description
Type 1 Anaerobic (they do not require oxygen to live); they make CH4 (methane) in anaerobic habitats: bottoms of bogs, lakes, sewage treatment ponds, and digestive tracts of animals.
Type 2 Aerobic (they require oxygen to live); they inhabit extra-salty environments: salt evaporation ponds, the Great Salt Lake, and the Dead Sea.
Type 3 Aerobic; they live in hot, acidic springs, at temperatures of 80C (176F) to over 90C (194F) and pH < 2!

Kingdom Monera
Life on Earth