The epibiotic bacteria living on R. exculata are known as chemoautotrophic which means they are able to fix carbon (break down carbon dioxide into organic carbon) (Jannasch, 1985). For this to be achieved, bacteria use chemical energy gained through oxidising inorganic compounds that are emitted from the vents. These compounds include, sulphur, nitrogen, hydrogen, carbon monoxide and iron (Jannasch, 1985). Bacteria need to remain close to the vent in order to access the supply of chemicals they use for chemosynthesis (Gebruk et al., 1993). Many types of bacteria at hydrothermal vent sites are filamentous and reside in moderate flows where the concentration of hydrogen sulphide is relatively low. These requirements affect the behaviour of the shrimp that need to provide the suitable conditions for the bacteria to grow; this will be discussed further down (Gebruk et al., 1993). The availability of chemical energy at hydrothermal vent sites is able to support an abundance of animals that are part of ecosystems that can be completely independent of energy from the sun (Jannasch, 1985). The deep sea shrimp is able to survive in this environment by harbouring another organism that supplies it with energy. Morphological adaptions have enabled R. exoculata to maximise the number of bacteria they harbour and to increase the efficiency of energy transfer (Petersen et al., 2010).