Emperor Angelfish – Pomocanthus imperator


The Emperor Angel truly merits this designation. This highly prized pet displays one of the most outstanding color patters of all the salt water angelfishes. This magnificent aquarium favorite goes through the most dramatic color transformation of any marine angel. The Emperor Angel is also known as the Kaiserfish.


The Emperor angelfish is collected from the Philippines, South China Sea, Melanesia, Micronesia, Red Sea, Indian Ocean, parts of the Indo-Australian Archipelago and as far north as Okinawa.


In nature the Emperor Angel is either found in pairs or are solitary in habit. They can be seen near the entrance of caves and ledges, which they dart into when alarmed. In the wild as in the home aquarium the Emperor makes a clicking and/or grunting sound when threatened.


The Emperor Angel can live for years in the home aquarium with the proper care. We have kept Emperor Angels for over 14 years in captivity. During this time we witnessed the entire color transformation from juvenile through adolescent to complete adult coloration. The entire color transformation took place in the first during the first 28 months of captive life.


Photo #1. When young, about 2″ (5 cm) they are marked with up to eight varying sized pure white to creamy white circles in the mid body. Each of these circles is one inside the other. There are also up to 18 smaller circles side by side on the upper rear portion of the body. There are also circles which have opened and now appear as curved lines toward the front of the body. All this over a deep velvet blue body. The tail is clear.


Photo #2. At about 4″ (10 cm) the Emperor Angel embarks into its adolescent color stage. The many white circles begin to open into straight yellow bars. At this phase the Emperor is at its least dramatic coloration.


Photo #3. Entering into adult coloration at about 5″ (12 cm) the Emperor Angel begins losing all circular body markings. These develop into horizontal yellow to golden bars. The face becomes pale with a few faint white semi circular stripes. The tail begins to develop a yellow color. At this stage the Emperor displays a relatively even mix of juvenile and adult colors.


Photo #4. When the Emperor Angel displays full adult coloration it is usually about 6″+ (15 cm+). The juvenile and adolescent markings have developed into yellow to golden horizontal bars on a rich deep blue body. The face displays a deep blue mask that is outlined in sky blue. The tail is a rich yellow to gold.


This entire color transformation can take place in the home marine aquarium in about 24 to 30 months. This depending on which color phase, size and age your Emperor Angel is when you get it. The minimum size aquarium to keep a juvenile, or adolescent turning into adulthood is 55 US gallons (220 liters). Larger aquariums will offer adults the ability to grow larger and perhaps at a faster rate. The Emperor Angel grows to about 14″ (35 cm) in nature. They can attain this size in aquariums with a minimum size of 200 US gallons (800 liters). In nature adult marine angelfish can control up to a quarter mile of area. Do not stress them in small or crowded aquariums.


Avoid mixing similar sized Pomocanthus or Holocanthus angels in the same aquarium. This can result in aggressive behavior as each angelfish will fight for and defend the same hiding places.


Emperor Angels collected from the Philippines are most common in the US aquarium trade. These usually display white circles when juvenile and yellow color bars when adult. Emperor Angels from the Indian Ocean and Red Sea have bright white to creamy white circles when juvenile and rich golden bar colors when adult. Emperor Angels and other marine life that is collected from the Indian Ocean, Red Sea and Australia are more costly when offered in the USA Vs animals collected from the Philippines. This is due to different collecting techniques and increased shipping and handling costs.


It is essential to provide a healthy, clean, and natural diet. Twice a week fresh clams can be offered. These are opened and cleaned. Any dirt, sediment and/or slime that may be inside the shell is carefully removed. The opened shell with clean clam meat is dropped into the aquarium. The Emperor Angel aggressively feeds on this natural diet. When feeding is complete, remove the clam shells. A daily diet consisting of a simple mixture of fresh minced scallop, prawn and clam mixed with Tetra(r) Marin flake food that has been soaked in Marine Vita-Pep‘ should be provided.


This simple mixture is formed into thin sheets and frozen inside of ziplock(r) bags. Prior to feeding, a small piece is broken off and thawed. The Emperor Angel and most other marine fish thrive and relish this healthy offering. Avoid over feeding clams or any other foods.


The Emperor Angel, like some other angelfish and surgeons/tangs can develop lateral line disease or exhibit color loss around the head when activated carbon is used in the display marine aquarium.


Avoid continual use of activated carbon on all marine aquariums. Carbon is usually used to remove medications. Always use the best items to keep your captive marine pets healthy. Maintain high water quality.


Use only the best marine salts. Review, How to Judge A good Marine Salt.