Nanoday | The World's Smallest Living Things

Welcome to Nanoday

Member Login

Lost your Password?

Not a member yet? Sign Up!

Sign in with Facebook

The World's Smallest Living Things

Posted by :Cambrian

Open Image – Click to copy code


When referring to nanoscience we mostly think of physics and chemistry. We usually think of biology as unrelated to nanotechnology except for the way the human body might be affected by nanotechnology. However, the world’s smallest beings also can be studied at the nano level. Just as size and structure determines the function of carbon nano tubes, it also determines the way organisms function on that level.


Smallest Archaea:

The smallest Archaea known to man is Nanoarchaeum Equitans. This microbe was found in 2002. It is a thermophile. Thermophiles are organisms that thrive in extremely high temperatures. The Nanoarchaeum has cells 400 nanometers across and is 490,885 nucleotide bases long. They need host organisms to survive like most living things at that size.


Smallest Bacteria:

The genus Mycoplasma holds the smallest free-living bacteria. They either act as a parasite or eat decaying matter much like fungi. Mycoplasma gallicepticum is the smallest of these species and measures 200-300 nanometers.


Smallest Eukarya:

The smallest Eukarya are the Myxozoa. There are many species of these creatures with size ranges of 10-20 nanometers. They are, in fact, multicellular organisms which is surprising considering their minute size. They live in dry and marine environments and are known to be parasitic animals.



There are debates on whether viruses are living or nonliving. This is a particularly interesting debate because it raises the question of what are the basic requirements for life. Most scientists claim that viruses are nonliving because they require a host cell to metabolize for them and they have no cell structure. A minority claim that they are living because they do well at employing the metabolism of the host and they have genetic material. If viruses are considered as living, the smallest being is the virus known as Porcine Circovirus type 1. It was found in 1974. It is not as dangerous as the second type which causes problems in the lymph nodes and lung tissue. Fortunately a vaccine was created in 2006. The virus’s capsid diameter is 17 nanometers and it is 1768 base pairs long.



Knowing and interacting with the smallest living beings in the world will lead to further breakthroughs in genetics and nanoscience. They might even help us create new life. Understanding viruses can help us to realize what life is. From a philosophical standpoint this is an important endeavor.


photo courtesy of

Tag(s) : nanoscience, biology, microorganisms, nanometer, virus, Eukarya, Bacteria, Archaea, ,    

Rate This


  1. rogersd923  - August 11, 2015

    we didn't knew that these things even existed, thanks to technology that we came to know about how tiny an organism can be and how they can effect our lives. thanks for sharing this post.

Back to Top