This reference work covering 546 native and 33 introduced species is a very important contribution on the biodiversity of freshwater fish species in Europe. Much of the information presented is drawn from original research conducted over 8 years in 24 European countries.

Includes:
- key to genera and species, diagnoses for all species
- methods for identification
- habitat, biology and ecology
- native, extirpated and introduced distribution
- conservation status, validated through IUCN procedures
- up-to-date taxonomy and nomenclature, with modern methods and concepts
- more than 870 bibliographic references