The queen danio or Fowler's danio (Devario regina) is a freshwater tropical fish belonging to the minnow family (Cyprinidae). Originating in India, Myanmar, Thailand, northwestern Malaya, and the Mekong River basin, this fish is sometimes found in community tanks by fish-keeping hobbyists. It grows to a maximum length of 3.1 in (7.9 cm).
In the wild, the queen danio is a rheophilic species found in fast-moving rivers with sandy bottoms in a tropical climate, and prefer water with an ideal temperature range of 73–77 °F (23–25 °C). Its diet consists of annelid worms, small crustaceans, and insects. The queen danio is oviparous.