aquatic 38 lotic 36 spring 36 benthic 32 very high temperature 28 sediment 27 marine 22 hydrothermal vent 22 sea floor 22 hot spring 14 fresh water 10 low salinity 10 medium temperature 4 low temperature 2 very high salinity 1 alkaline 1 high temperature 1 lentic 1 lacustrine 1