What are halophilic, thermoacidophilic and methanogen archaebacteria?

These are three types of archaebacteria. Halophilic archaebacteria only survive in salt-rich environments (even the salinity of the sea is not enough for them). Thermoacidophilic archaebacteria are characterized by living in high temperatures and low pHs. Methanogen archaebacteria are those that release methane gas (CH₄). They are found in swamps.