Emperor Angelfish (Pomacanthus imperator)

Few fish demonstrate a more complete transformation than the Emperor Angelfish — juveniles wear a psychedelic swirl of blue-and-white rings that looks nothing like the crisp yellow horizontal striping and blue mask of the adult, a process so thorough that early naturalists once classified the two life stages as different species entirely. One of the most recognizable and requested marine angelfish in the hobby, and every bit the showpiece its name promises.

Care level: Moderate · Temperament: Semi-aggressive · Max size: ~15" · Min tank: 180+ gal · Diet: Omnivore, marine algae + meaty foods