aquatic 65 spring 61 lotic 61 hot spring 39 benthic 35 very high temperature 30 sediment 23 sea floor 22 hydrothermal vent 22 marine 22 low salinity 14 fresh water 14 high temperature 4 low temperature 2 lentic 2 medium temperature 2 lacustrine 2 anthropogenic 2 contaminated 2 terrestrial 2 subsurface 1 alkaline 1 mine 1 very high salinity 1