The Amur bitterling (Rhodeus sericeus) is a small freshwater fish native to Eastern Asia, particularly the Amur River basin. It is known for its shimmering scales and vibrant colors. This species has a unique reproductive relationship with freshwater mussels, using them as a safe place to lay its eggs. The Amur bitterling shares this fascinating reproductive behavior with its European cousin, the European bitterling (Rhodeus amarus). Despite its small size, the Amur bitterling plays an important role in its ecosystem and serves as a captivating example of symbiosis in nature.













