R. Kapeller

About this project and this database


What made me start this project?

Apart from my interest in mollusks, which I am collecting and studying since decades, my passion for nature photography and my enthusiasm for developing computer programs, the fact that I have not yet encountered a really useful, comprehensive identification tool.

Depending on whether they are printed or electronic, they all have at least some of the following disadvantages:

A thorough research on the available works has shown that there are useful identification works for only a small number of limited scopes: for example, the online portal of the NHM WALES [27] for marine bivalves around the British Isles or the web-page of the Stuttgart Natural History Museum [1045] for the mollusks of Germany or the works of Glöer [4][91] for the freshwater mollusks, the latter printed only. The more comprehensive the works become, the more the weaknesses become apparent.

This is of course a very personal view from some decades of collecting and identification work and should in no way be a disparagement of the enormous work that has been done in this area so far. But outside of the scopes mentioned, I have repeatedly found that the identication of a less common species can turn into a laborious search for literature. And that's how the idea for this project came about.

Goals of the Project

The project intends to provide a comprehensive determination tool for European mollusks, avoiding the above mentioned weaknesses as far as possible. In particular:


When speaking of 'completeness', the orientation needs to be addressed, because there is no 'official' list of accepted species, rather it is necessary to judge the arguments in individual literature, which are not always unanimously.

In a project of this scope, it is impossible to review every single species in depth. Therefore, this database is largely based on the systematics of the Molluscabase [56] or WoRMS [29] for marine species, as these offer the most comprehensive and largely up-to-date overview. Deviations from this are always explained in detail.

Additions have been made where the original literature provides sufficient evidence for the existence of a new species and it has to be assumed that Molluscabase is incomplete on that point. This also applies to species that are listed as synonyms in Molluscabase if there is sufficient evidence for a distinct species in recent literature.

On rare occasions, species currently considered valid have been excluded as 'not valid within this identification key' when there is a lack of conclusive evidence for the existence of a new species in the original literature. In these cases, the species is listed as a synonym in the taxonomic remarks so that it can be found in the taxon search. In any case, the reason for exclusion is explained in detail. As mentioned, this was necessary in very few cases. Taxonomic discussions are not a primary goal of this project.

Covered area

The covered area is shown schematically on the title page. It includes the land area of Europe in a geographical sense, all European islands including the Atlantic archipelagos, all European coastal waters, as well as the deep seas of the Mediterranean, Arctic and North Atlantic, west to the Mid-Atlantic ridge.

In addition, species have been included that have not yet been recorded from this area, but which can be assumed to occur here or to arrive here in near future. This applies in particular to species that have migrated from the Red Sea to the Mediterranean and have already reached the southern coast of Turkey, as well as West African species that also live in deeper zones and could therefore also occur near the Canary Islands.


The database essentially contains the following elements:


The design is deliberately simple and unpretentious, not (only) to underline the scientific character, but so as not to distract the eye from the essentials. Species identification in mollusks is difficult enough. Therefore the main focus was on clarity, even in the design.

Time schedule

As already mentioned on the home page, the database and identification key can currently be used for marine snails and mussels as well as for freshwater snails and mussels.

Land snails are a work in progress and are expected to go online towards the end of 2023. The other classes will then follow step by step. After completion, the first revision can be started, especially to add newly discovered species.

This schedule is a rough estimate and cannot be guaranteed. Frequently one comes across a species or group of species for which there are very controversial data, the elucidation of which can be difficult and lead to considerable delays.

Unlike some works, in which descriptions and other data are simply copied together from various sources without checking, regardless of the resulting inconsistencies, I check the data for each species carefully and try to create a consistent building.


Some data on the current status of the database: