[Taxacom] Species Numbers

Arthur Chapman taxacom3 at achapman.org
Thu Sep 18 07:43:09 CDT 2008

Dear Brian

Indeed - a problem!  As you can see from my publication, in many places 
I cite "unknown" for many of the prokaryotes and others lower 
organisms.  Wherever possible though, we have cited whatever published 
estimates there are.  Sometimes, we are only able to provide a range.

For example, if you look at the viruses (page 45) - we have stated that 
"The main problem in estimating the number of species of viruses is 
knowing just what constitutes a species in the group" - and indeed we 
have had many discussions on what is a species on Taxacom over the 
years.  You will also see that for the viruses I have found some 
estimated numbers for the World, but not for Australia.  Indeed a 
problem, but for a publication such as this, it is only possible to cite 
what people have published, or are prepared to give me, and any number 
is at least a starting point for discussion.

For the Bacteria (Monera), excluding Cyanobacteria estimates for the 
world vary from 50,000 to over 3 million, and for Australia with only 
around 40 described species, the estimate is that this may only be 0.1% 
of the total number of species.

As you mention - the prokaryotes are indeed a problem.

The publication cites both described and estimated for all groups where 
I have been able to find any information.  If you go through the 
publication and are able to put any figures for any of those groups it 
would be appreciated. As much as providing information on what we do 
know, and what we think we may know, I think such a publication gives a 
strong indication of just how much we do not know.

I appreciate your input.


bti at dsmz.de wrote:

Dear Arthur,
the problem with such a report is that it probably centres on the  
number of "species that have been named". In the case of prokaryotes  
the list I saw last gave the impression that Australia was virtually  
void of prokaryotes. The clause under prokaryotes is that although  
about 10,000 names have been registered (with emphasis on  
registration) under our Code the actually number of taxa to be  
discivered and characterised properly is probably comparable with the  
number of botanical and zoological taxa combined. The published data  
clearly supports this hypothesis. We humans are a walking ecosystem,  
providing a home for anywhere between 800-1,000 species (a good number  
of which are essential to our survival). The lowest level of all  
ecosystems are microscopic organsims, which we tend to ignore in our  

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