The rosy bitterling or Tairiku baratanago is a small freshwater fish belonging to the family Cyprinidae, native to East Asia from the Amur River basin to the Pearl River basin.
Females are about 4–5 cm (1.6–2.0 in) long and males are 5–8 cm (2.0–3.1 in). Their bodies are flat with an argent-colored luster. However, males change to a reddish (sometimes purple) color during the spawning season (March to September) which functions to attract females. This reddish color is similar to the color of a red rose, which is why it is called a rosy bitterling.