The queen danio or Fowler's danio (Devario regina) is a species of freshwater ray-finned fish belonging to the familyDanionidae. 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 3.1in (7.9cm).
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.