Bergey's Manual is a complete Bacteria GSD.
Bergey's and AlgaeBase - world coverage
2-300 spp., ITIS does N. America
~7000 spp., AlgaeBase - world coverage
1500 spp., TROPICOS - world coverage
~90 spp., AlgaeBase - world coverage
7000spp., AlgaeBase - world coverage
250 - 1000 spp., AlgaeBase - world coverage
ITIS and AlgaeBase - world coverage
~200 spp., AlgaeBase - world coverage
~2000 spp., AlgaeBase - world coverage
~1600 spp., AlgaeBase - world coverage
~500 spp., AlgaeBase - world coverage
6500 spp., some treatments, not online.
~1700 spp.AlgaeBase - world coverage,
~500 spp., AlgaeBase - world coverage
~7000 spp., AlgaeBase - world coverage
600 spp., AlgaeBase - world coverage
Well treated;World List of Cycads, John Hendricks
250spp., good treatment
ITIS treatment for N. America
ITIS treatment for N. America
ITIS treatment for N. America
ITIS treatment for N. America
258650 spp., level of treatment captured by GSPC Metadatabase. Some commercial families at a very high level of treatment.
No data
15000spp., ITIS has N. Am data; otherwse some non-web treatments
72000 spp., Extend of Species Fungorum Unclear.
600 marine species, no treatment encountered. AFAIK some commercial importance as parasites to commercial fish
ITIS well under way with global treatment, maybe excepting Hirudinea.
no data
Spiders; 'All' (c. 40000) known species catalogued
Acari; No estimates. Except for ticks, no treatment. Commercially and medially important as parasites, vectors and vermin. A significant gap!
Other orders + Pycnogonida; no data
40000 spp. very patchy except commercial Decapoda and a few other groups (isopoda). Large biodiversity Gap
Major orders with a certain level of treatment in progress. Networks of collaborators forming
Lack of treatment may be important Gap
Chilopoda; to be completed
Diplopoda; only N. America in ITIS -Significant Gap
No data
No data, major part of Zooplankton, 70-100 spp.
Gap?
2000+ spp. no treatment
Gap?
Good - although sometimes competing - treatments.
8000 spp. no treatment - a possible Gap
ITIS + Hexacorallians of the World seem to cover the group
Small taxon (90spp.), a species list exist at http://faculty.washington.edu/cemills/Ctenophores.html go get it
2 spp.
7000 spp., no treatment - Major gap
140 spp., no treatment
5000 spp., treatment (Lidgard, FieldMus) in progress
~170 spp.
400 spp., no treatment
80 spp., some treatment
100 spp., no treatment
100 spp., no treatment
10spp., no treatment
>75000 spp. Except for Cephalopoda, the treatment is geographically segmented. more investigation needed. Possible Gap(s)
no data
25000+ spp., no online treatment GAAAAAB!!!
240 spp., no treatment
1000 spp., emerging treatments
Few, no treatment
20 spp., list on Wikipedia
10-16 spp., no treatment
1sp., no treatment...
18000+ spp., ERMS has European data, but no world treatment exist. This is a medically and agriculturally very important group (parasites). Major gap
10000 marine spp., except for ERMS, no treatment. Gap
8spp., no treatment
Some treatment of Foraminifera. All other lacking. Major gap
65spp., no treatment
<2000 spp., no treatment except FaEu
1500 spp., no treatment. Ecosystem importance. Gap
150 spp,. no treatment except ERMS
180 spp., no treatment
A number of Phyla/Divisions totally lack taxonomic treatment. Also, for the same groups it is often hard or impossible to obtain figures for the number of species they contain. These groups are in general under studied and often totally lack a taxonomic community. Seen in isolation, they may not present significant gaps as these groups are in general fairly small, but in concert they constitute a major gap that will be hard to overcome.
Significant gaps can be perceived for Acari, Nemata and the Platyhelminthes . These are all mega diverse groups with significant medical and economic importance as either pests or parasites. These groups might be highlighted in a prioritization process.
Even as significant gaps occur in Crustacea, Diplopoda, Echinodermata, many Insect orders (the major insect orders all have a reasonable level of treatment, but a good number of medium size orders remain untreated) and Porifera . These are medium size to large animal groups that have no treatment but may not be of as high an importance as the previous.
The treatment status of the Magnoliophyta (flowering plants) is monitored by the GSPC meta database. Although certain gaps exist for a number of families, the Magnoliopsida are in general well treated. Certain economically important and large families are indeed among the best treated groups.
The Fungi is a very large group and only a few treatments exist. However, the initiatives taken by Species Fungorum aim at covering 40% of the species at the end of 2005 and the Fungi as such can not be considered a gap. Certain groups of Fungi may even though be without any possibilities for treatment and could be considered gaps.
The Bacteria (including Archaea and Cyanobacteria) are treated in Bergey's Manual of Bacteriology and represent one of the most complete treatments available.
Viral names and species are handled by the ICTVdB