Spiders in Fauna Europaea : dual use of the database

The history and current work of the project Fauna Europaea is outlined. The different sources used for building up the database and the efforts to keep it updated are described. Available models of national checklists are discussed and the ideal checklist is described. The double use of the database as a matrix behind the official site of Fauna Europaea – as well as a directly visible document on the website of the European Society of Arachnology – are indicated and the differences in transparency, links to literature sources, and facilities such as distribution maps and calculations of numbers of scores per species or of species per country are discussed. The future of the project is briefly outlined. The need for a European identification tool for spiders is stressed.


Sources
General sources I built up the database for the spiders in 2003 and subsequently try to keep it up-to-date with the much appreciated help of many colleagues from all over Europe, and based on different sources.
The available literature forms the ever increasing primary source for the database. I started to work with Platnick's World Catalog (PLATNICK for the years [2002][2003], extracting all the names of spider species in Europe, and next browsed the literaturelibraries, the internet. Zoological Recordfor distribution data and newly described species. Platnick provides a fresh version of his Catalog twice a year and the changes in his catalogue, nomenclatorial changes as well as new species and distribution data, form one of the sources for the regular update ofthe Fauna Europaea database. Platnicks Catalog is a reliable source for taxonomic registration but less detailed in its indication of the distributions, which are summarized where appropriate (e.g. Palaearctic, Western Mediterranean). For zoogeographic purposes, therefore, all possible literature sources are browsed, such as papers published in journals, checklists published on paper, or on the internet.

The British checklist
In the checklist of the British Isles (BRITISH ARACH-NOLOGICAL Society 2011) the families are grouped in taxonomic clusters, which make such a list slightly less user-friendly. The alphabetical order is not used. 59 not even within a family, which renders the list extremely user-unfriendly and frustrating. In this particular case one sticks to a traditional sequence followed in identification literature which is not functional even there and lacks a scientific or practical basis. For example, the taxonomic clustering within the Linyphiidae does not have any phylogenetic basis and is not explained. Recent changes are not marked and it is not clear if and when updates were carried out. The consultation of such a checklist thus becomes a tedious job.

The website of Fauna Europaea
The website has not changed its visual format since its launch in 2004, but the possibilities and facilities have greatly improved since. The site allows the user to check the occurrence of all known spider species in all European countries. Using the "Distribution" button one can request an overview of the distribution (presence or absence per country) of each species, or extract a distribution map showing the country distribution. One can find the numbers of species within a family or a genus occurring in Europe and can request a map of the distribution of that taxon.
Detailed information is offered on the number of European species within a genus. Through the "Taxon Tree" one can zoom in on every taxonomic unit, from family down to (sub)species and find answers to the above questions.
However, it is impossible to extract a complete list of all spider species for a country. Likewise it is impossible, or is apt to fail, to get an answer to the number of species for a country. The database holding all the data remains hidden behind the screen. There is also no entry to literature references. This should be improved upon in the future.

Hosting by tbe European Society ofAracbnology
The same database in spreadsheet format was offered by the author to the European Society (ESA) for general use; an initiative welcomed by ESA. The database is accessible through links on the ESA website for two Excel spreadsheets, one for nomenclature ("Taxonomic Sheet") and one for distribution ("Faunistic Sheet"). In the last column of the taxonomic sheet the numbers of literature references can be found which relate to the numbered list in the separate document "References". The second part of the latter document contains entries to the main faunistic sources for each country, such as printed catalogues and checklists as well as links to internet sites with such information.
There are no facilities to convert the data into maps.
Since the original spreadsheets are available for examination one can immediately see which species occur in each country and from which countries each species has been recorded. One can also count the species for each country, by counting through the columns or automatically via spreadsheet facilities. This is already carried out for each new version which appears on the ESA website where the bottom row and the last column but one provide these additions.
The presence of a species is indicated by a "P". Nomina dubia and imported (non-native or invasive) species are indicated in the database, as "nd" and "Pi", respectively, but are not included in the automatic count, thus excluding them from the "Indigenous fauna" of the country, here called "true species".
Tab. 1: Composition of the spider fauna of Europe.

PJ. v.Helsdingen
The taxonomic table allows nomenclatorial changes to be followed and the tracking of changes in taxonomic status (synonymies, changes in taxonomic level).

Possibilities for statistical analysis
Analysis of this last but one column revealsexcluding nomina dubia and non-native (imported) species a strikingly large number of records from only one country or region (Tab. 1). Such unique records form 45.4% of all species; a surprisingly high score (Tab. 2).
Among these are, of course, all the endemic species found in a single country. Among these "unica" we may also expect potential synonyms awaiting recognition by revisers. Ifwe carry out the analysis for families we find for some families even higher scores than the 45.4% for the overall European spider fauna (Tab. 2).
Families with much higher percentages of such unica or one-country species are the Dysderidae (70%), Nemesiidae (58%), and Zodariidae (57%). This agrees with the recognized speciation patterns in these families as indicated in the literature. In and the Zodariidae, which were studied thoroughly by PekAR et al. (2003,2005,2011) andBOSMANS (1994,1997,2009