Ornamental fishkeeping has become one of the most popular hobbies globally. The entire industry is valued at approximately US$15-30 billion per year and the international market may involve more than 100 countries. Over a billion wild-caught or captive-bred fish belonging to more than 6 500 species are sold annually. Yet, few laws or regulations are in place to control the aquarium fish market. The industry should aim at promoting sustainability through the development and deployment of best practices and standards, particularly taking into account the welfare of traded fish.