Modern ornamental aquaculture in Europe: early history of freshwater fish imports.
Modern ornamental fishkeeping is one of the most popular hobbies in the world, with various known positive and also negative aspects including the introduction of non-native species. Despite this fact, the history of the first imports of freshwater tropical fish species for ornamental purposes has never been deeply studied and is usually simplified. Here, we present the first comprehensive review of reported imports in the period of the early history of this sector of aquaculture, ending with the end of the First World War. Moreover, the total number of kept species has been updated, with a forecast for the future. We present the summarised information in a wide context of both historical and current connections and viewpoints, highlighting the crucial role of German importers at this time. In this regard, the term 'German aquarium phenomenon' is proposed.