The Blue Devil Damsel, Chrysiptera cymatilis, is a bright dark blue damselfish with clear back and anal fins. The Blue Devil Damsel is aggressive and should not be paired with fish of its own species, or smaller passive fish. They will eat most meaty frozen foods as well as flake foods. They should be kept in a minimum tank size of 30 gallons and they can reach up to 3 inches in length. This hardy fish is a strong candidate for a beginner tank.