aquatic 27 lotic 25 spring 25 benthic 21 sediment 18 very high temperature 17 hot spring 14 hydrothermal vent 11 marine 11 sea floor 11 fresh water 10 low salinity 10 medium temperature 2 low temperature 2 lentic 1 lacustrine 1 very high salinity 1 alkaline 1 high temperature 1