Purple sulfur bacteria (like green sulfur bacteria) typically form blooms in non-thermal aquatic ecosystems, some members have been found in hot springs. For example "Chlorobaculum tepidum" can only be found in some hot springs in New Zealand at a ph value between 4.3 and 6.2 and at a temperature above 56 °C. Another example are "Thermochromatium tepidum", has been found in several hot springs in western North America at temperatures above 58 °C and may represent the most thermophilic proteobacteria existent. Of the purple sulfur bacteria, many members of the Chromatiaceae family are often found in fresh water and marine environments. About 10 species of Chromatiaceae are halophilic.