Figure 19.18: A Nanoarchaeote Growing in Mixed Culture with a Crenarchaeote Nanoarchaeum equitans (red), discovered living near deep-sea hydrothermal vents, is the only representative of the nanoarchaeote group so far identified. This tiny organism lives attached to cells of the crenarchaeote Ignicoccus (green). For this confocal laser micrograph, the two species were visually differentiated by fluorescent dye “tags” that are specific to their distinct gene sequences.