Like two different fish, adult and juvenile emperor angelfish look completely different. It was once thought that the two forms were two completely different species. The body of the juvenile is a dark bluish black. It has a light blue line near the tail with a white circle around it. This white circle is surrounded by alternating light blue and white incomplete circles.

When the juvenile reaches a length of 5 inches (12 cm), the colors completely change.

Minimum tank size:

90 Gallons as a juvenile, but 125 gallon once Imperator matures to adult size.

Reef Compatibility:

Will nip at sessile invertebrates such as nudibranchs, corals, and clams.

Food and Diet:

In the aquarium they should be sustained by a wide selection of live, fresh, or frozen and vitamin-enriched brine shrimp, mysis shrimp, chopped krill, chopped clams, chopped squid, marine algae, zucchini, spinach, romaine lettuce, and quality Spirulina-based flake foods for angelfish and herbivores.

Feed them at least three small meals a day to help support their fast metabolism.

If a specimen doesn't initially eat during acclimation, they can be enticed with live brine shrimp, ghost shrimp, and freshly chopped seafood.

Level of Care: Moderate

Approximate Purchase Size:

 Small: 1" to 1-3/4";Medium: 1-3/4" to 2-1/2"; Large: 2-1/2" to 3-1/4"