Please visit our Sponsors

Related FAQs: Imperator AngelfishEmperor Angels 2, Emperor Angels 3, Emperor Angel ID, Emperor Behavior, Emperor Compatibility, Emperor Angel Selection, Emperor Angel Systems, Emperor Feeding, Emperor Disease, Emperor Disease 2, Marine Angelfishes In General, Angelfish ID, Selection, Behavior, Compatibility, Systems, Health, Feeding,
FAQs on Emperor Angel Health:
Emperor Disease 1, Emperor Disease 2, Emperor Health 3, Emperor Health 4, Emperor Health 5, Emperor Health ,
FAQs on Emperor Angel Health by Category: Diagnosis, Environmental, Nutritional, Pathogenic (see also:
Angels and Butterflyfishes & Crypt), Social, Trauma, Genetic, Treatments

Related Articles: Pomacanthus Angels, Marine Angelfishes

An Emperor Amongst Angelfish, Pomacanthus imperator


Bob Fenner  

Angelfishes for  Marine Aquariums
Diversity, Selection & Care
New eBook on Amazon: Available here
New Print Book on Create Space: Available here

by Robert (Bob) Fenner

Amongst the most popular of the thirteen members of the genus Pomacanthus, indeed amongst all marine Angels, the Emperor/Imperator is a gorgeous centerpiece for large aquariums or chance encounters in its large Indo-Pacific (and Red Sea) range.

            By paying attention to source/locality, carefully picking out an initially healthy specimen of moderate size; providing it with a mix of useful foodstuffs, and paying attention to its behavior amongst all else in its system, you can have a large, intelligent specimen for several years.


Unmistakable as adults, juvenile emperors resemble some other angels as juveniles. Look at how the white dorsal fin margin and how white, blue and black oval lines meet near the tail for the real thing. Below, a three incher, a five inch changeling and a ten inch fully colored adult.


Distribution and Habitat:

            The Emperor Angel is found sporadically over its range in the Indo-Pacific and Red Sea; the young darting about within hard structure on reefs, adults occupying ledges and caves; mostly constantly on the move. They are usually encountered as solitary individuals though they may travel in pairs as adults at times. The species is definitely reef-associated; and though it may nibble on anemones, soft corals and LPS is generally safely kept with SPS, Zoanthids, and other Cnidarian groups.


            Emperors rarely get along with other large Angelfish species (unless they’re purposely crowded in very large systems); though they may become acclimated to tolerating smaller species by growing up with them. Their penchant for consuming stinging-celled life has been mentioned above.

Selection Criteria:

            There are quite a few things to select for in picking out a good specimen… and avoiding the ones that historically don’t do well:

Size matters: A specimen of 3-4 overall inches is best to start with. Too small ones ship and adapt poorly as do larger.

Source location: Can be important. Philippines and most Indonesian (other than Bali) Emperors do less well than specimens collected elsewhere. Red Sea individuals are exemplary when and where they can be procured. IF in doubt as to the origin of the fish, DO make sure you observe it being fed, it eating for a few days… lest it have been collected with poison.

It should be bright: That is alert, aware of your presence. Leave specimens at the shop that are having private parties; hanging in corners, oblivious to your presence.

Look for obvious signs of pathogenic disease: Too rapid breathing (more than 80 gill movements per minute); too torn fins, cloudy eyes… can spell parasitic involvement. Most if not all wild-collected Angels have some to significant parasite fauna. Coverage on how best to deal with these is offered below under “Disease”.

Caution when netting, handling: As with all angelfishes (the meaning of their family name Pomacanthidae), watch out for their opercular spines… these are easily fouled in nets and can deliver a painful spike if jabbed in your hand.


            An Emperor Angel tank needs to be large enough for an adult specimen ultimately… at least a hundred gallons for a juvenile of four inches (10 cm.), 240 to 300 gallons minimum for an adult. These fish suffer psychologically for insufficient room to move about. Stunting one by crowding, metabolite build-up, will result in a physically and mentally stunted individual of shortened lifespan.

            This fish can be kept in FOWLR settings, but does best in reef quality water of little nitrate and phosphate accumulation.


            In the wild P. imperator feeds principally on sponges, sea squirts and other benthic invertebrates. In captivity it is strongly suggested to provide a modicum of sponge material through live rock, prepared foods, in addition to a good staple pellet and frozen/defrosted foods. Twice or more daily feedings will keep your Angel alert and imprinted on you as a food source.


            Cumulative stress is often the root cause of breakdown of Emperors, starting with even the best quality. I cannot over-emphasize the need to isolate (quarantine if you will) new specimens, as they all have imported flukes and Protozoan issues. I highly recommend a vermifuge treatment (Prazi or such) and anti-protozoal dip/bath (pH adjusted freshwater, with aeration and formalin if you can) to knock off these external pests, and avoid their introduction to your main/display system.

            Resistant Protozoan infestations are best treated with Quinine compounds, the best to date is Chloroquine phosphate (CP).


            Separate sexes that are hard to discern; this fish has been spawned and raised (some numbers by Bali Aquarich currently).


            Do you have a few hundred gallon display looking for that certain show specimen? Are you and your tankmates tolerant of a bit of nipping, sampling? I do encourage you to consider a large Angel for your showcase animal; and the Emperor as king amongst them.


Angelfishes for  Marine Aquariums
Diversity, Selection & Care
New eBook on Amazon: Available here
New Print Book on Create Space: Available here

by Robert (Bob) Fenner
Become a Sponsor Features:
Daily FAQs FW Daily FAQs SW Pix of the Day FW Pix of the Day New On WWM
Helpful Links Hobbyist Forum Calendars Admin Index Cover Images
Featured Sponsors: