The gudgeon is a common prey of many fish-eating predators like Eurasian otter or common kingfisher. In Central Europe, on streams and rivers, gudgeon composes up to 45% of the diet of common kingfisher (by numbers, usually between 25 and 35%) and represented the most hunted fish prey.[4][5][6] One study has shown that gudgeon composed over 80% of the diet of otter by numbers and over 50% of the diet by weight (Chotýšanka stream, Central Bohemia, Czech Republic).[7]