<Li> Alkaliphiles, optimum growth pH of greater than 8, including the genus Natronomonas . </Li> <Li> Acidophiles, optimum growth pH of less than 3, including the genera Sulfolobus and Picrophilus . </Li> <Li> Piezophiles, (also known as barophiles), prefer high pressure up to 130 MPa, such as deep ocean environments, including the genera Methanococcus and Pyrococcus . </Li> <Li> Halophiles, grow optimally in high salt concentrations between 0.2 M and 5.2 M NaCl, including the genera Haloarcula, Haloferax, Halococcus . </Li>

Eukarya are single-celled prokaryotes and one of the largest groups of organisms on earth