The Great Barrier Reef Library

A comprehensive guide to The Great Barrier Reef


By on May 23, 2018


The name Archaea has Greek origins, Archaios, meaning ancient.1 They were previously classed within the Domain of Bacteria, until their distinct evolutionary history was discovered. Whilst many similarities are present between the two Domains, Archaea have a couple of key differences. Firstly, they are unable to produce spores and secondly, their cell walls are constructed from different molecules to bacteria.2

Similarly to Bacteria, very little is known about the role of Archaea on The Great Barrier Reef, however, they are another vital component. They are found all over Earth, particularly in extreme environments. Whilst we used to believe that this was their only habitat, we no know that they make up a large portion of the microbes found in the ocean.2 Archaea hold the record for living in both the hottest and most acidic environments (113 degrees Centigrade and 0 pH respectively).1

Like bacteria, they are tiny, unicellular organisms, with a simple cell structure. Organelles are absent, with the exception of Ribosomes, used to build proteins. Their genetic materials lies free within the cell, coiled into a Nucleoid, rather than being held within a Nucleus.2

Also like Bacteria, they may be primary producers as either Autotrophs, or Chemotrophs, or they may be Heterotrophs. They are also responsible for the decay of organic matter and recycling of nutrients.2