There is currently an increasing demand for diversification of cultured fish species production. However, currently domestication of new species is largely achieved by Iona, costly, and usually empirical zootechnical approaches, which show much scope for optimization. Within this context, it was considered worthwhile to try to develop a generic approach that may aid understanding of the process of domestication in the long term, and to foresee how a new species may be domesticated. As a first step towards the development of such an approach, we described a new functional classification of 65 freshwater species, chiefly inhabiting European waters. This classification, based upon the analysis of 29 reproductive traits, contained seven main groups or guilds. The major traits that separated these guilds are ego (i.e., buoyancy, temperature and degree-days), larvae (size and behaviour) and spawning conditions (breeding period, temperature, spawning site preparation and parental care). We confirmed that it is not feasible to make generalizations solely on a taxonomic basis, since most guilds contain phylogenetically distant species. In conclusion, this new classification system, differing significantly from all other previous classifications, could now serve as a possible framework helping to enhance the domestication of new species, especially in European countries, by comparison of species to those belonging to the same guild.