Emperor angelfish

The emperor angelfish is a large marine angelfish of the family Pomacanthidae, widespread across the Indo-Pacific. Adults are unmistakable, with horizontal blue-and-yellow stripes and a dark blue eye mask, while juveniles are dark blue with concentric white and electric-blue rings, an entirely different pattern. It is a bold, territorial fish that establishes a strong presence and can dominate tankmates. Only one should be kept per tank, and it is best added to a community of robust fish rather than timid species. It needs a very large aquarium with abundant live rock for grazing and hiding. Its diet must be varied, including marine sponges, angelfish preparations, algae, and meaty foods, and it may nip stony corals and clams. It is a protogynous hermaphrodite that is very difficult to breed in captivity.