Currently there are a lot of fish that are used by many fans in aquarium care, one of the most popular being is the Emperor angelfish or Pomacanthus imperator. Learn all about it, from its main characteristics to the care that you should have at the time of having it in captivity, let’s begin.
Table Of Content
Taxonomy
Common name: Emperor Angel Fish Order: Perciformes Family: Pomacanthidae Genus: Pomacanthus Reference: Bloch, 1787
Emperor Angelfish Main Characteristics
The emperor angel fishes in their juvenile and adult form differ from one to the other so that previously they were categorized as different species.
Adult specimens have a deep, subtly elongated body, and have yellow and blue horizontal lines 
that start behind the gills a little before the tail that is yellow.
The dorsal and the anal fins are also blue and have some equally tonal streaks.
The first one has a white border and its mouth also has a white hue, which is cut abruptly by a black mask covering the eyes.
The mask is black, bordered in blue and has a yellow vertical bar that extends from the head down. The bar divides the black mask with a thicker vertical band that begins at the bottom of their body and continues down the pelvic fins.
This black band is in the same area of vertical space as the pectoral fins and gills. We invite you to read our article the anatomy of fish to learn more about such a topic
On the other hand the juvenile Emperor Angel fish is black with vertical lines in light blue and white on the face.
Behind the gill area has three thicker white bands, the first is a curved strip that starts from the dorsal fin to the anal fin. The second line has the shape of a «C» and the third form a white circle near the tail fin.
In the midst of these white ribbons are other thinner light blue, dorsal and pelvic fins have a honeycomb pattern that is black in the middle and with the edge in light blue. On the other hand the upper dorsal fin has a white top edge; these fish begin to change color when they measure between 8 to 12 centimeters.
The sub-adult resembles the juvenile emperor, except that the tail fin has a yellow color, while vertical yellow scripts begin to appear in the body, mixing in the juvenile pattern.
The sub-adult also develops a Body deeper and rounder, like the adult.
These fish are deep-bodied and can grow up to 40 cm in the wild, but in captivity, usually only reach about 30 centimeters.
Adults are usually found alone, but they can also socialize in pairs, trios, or harems of a male with two or more females.
They live at depths between 1 to 80 meters and sponges, encrusting organisms and tunics being their main food. So far, their captive breeding is not possible as the rearing tanks of these angels have not succeeded. It has been claimed that the blue in front of the eye mask is bluer in the male Emperor Angel Fish, and is a bluish gray in females.
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Habitat and Distribution
The emperor Angelfish inhabits shallow water in reefs and corals. Another aspect that is known 
according to the studies applied to the habitat of this species is that they are not migratory animals.
On the other hand, according to what is considered the ideal habitat for emperor angel fish it ranges between 23 ° C and up to 29 ° C.
It’s also known that this species is kept swimming at no more than 100 meters deep, even can be found only one meter from the sea’s surface.
In the same way it should be noted that mainly these fish will be found in the main caves of these coral environments.
Among other aspects, it is known that this species is formed by a stable population, which in turn does not face greater risks in terms of the danger of extinction.
In this way it can be said that these populations are mainly located in the waters that make up the Indo-Pacific region, (mainly in Australia). Currently its population extends to more than 60 countries.
How Does Emperor AngelFish Reproduce?
It mates once a year in the Marshall Islands between August and September. Males will have 2 or more females in their harem. Each female has her own territory, and sometimes they are surrounded while the male releases his sperm and the females her eggs at the top of the 
water.
The larvae float at a planktonic stage for a few weeks before becoming juvenile, while males are known for growling as spawning occurs.
A study conducted in 1978 by Moyer and Nakazono describes the reproductive habits of Japanese Angel fish (Centropyge interruptus), a species found in harems containing a single dominant male and one to four females.
Harems exhibit a hierarchical system of domination and if the male is removed from the harem, the higher-ranking female will change to male sex for around two to three weeks.
Pomacanthus have several types of mating systems, depending on the population density in the location where they are located.
The harem consists of a male defending several females in a small area or in a large group that unite to spawn, in all species, however, these fish reproduce in pairs. The couples get together at the edge of the reservoir at dusk, usually above the substrate.
Each couple engenders and ascends in the water column, swimming together in an arc about 2 – 3 meters above the substrate to expel the pelagic eggs at the top. in the spawning system of large groups are quite promiscuous, and males often try to interrupt the Spawning of the congeners.
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Emperor AngelFish Feeding
Emperor Angel fish are omnivorous creatures and their favorite foods is algae and sponges, but also eat small invertebrates. In Aquarius you can offer them Artemias, Tubifex, worms, etc., without forgetting the vegetal component (for example, a leaf of lettuce).
Emperor AngelFish’ Behavior:
These fish are characterized by having solitary life on coral reefs. The adult specimens defend their territory, especially from the incursions of fish of the same species. Males have harems of 2 to 5 females. In Aquarius only a few individuals can be bred, offering them numerous shelters. If he’s scared, he emits a strange sound.
Associated Species.
Let’s learn about the whole family
Lamarck’s angelfish (Genicanthus Lamarck)
This species belongs to the Pomacanthidae family and is very distributed through the tropical waters of the Indo-western Pacific. They feed on plankton along the coral reefs. lamark angelfish has sexual dimorphism, as the male is larger with blackish pelvic fins and a yellow spot on the front head, while the smaller female has whiter pelvic fins.
Holacanthus Ciliaris (Queen angel fish)
This is a striped- fin fish in the Pomacanthidae family, found in the Indo-western Pacific Ocean very common in the aquarium trade.
They are deep-bodied fish, compressed laterally, which can grow up to a length of 35 centimeters. Adult specimens have a pale brown-green color while their scales have blue bases that give the body a mottled effect.
The fins, with the exception of Pectorals, are bordered in blue, the dorsal fin having 13 thorns and 20-23 soft rays and the anal one has 3 thorns and 18-22 soft rays.
Both fins have filaments that slide backwards when the fish swims, the pectoral fins are pale yellow and have 19-21 soft rays.
The juvenile individuals in contrast, are blue with black marked from top to bottom with narrow white stripes.
At the end of the head the stripes are quite straight, but they become more and more curves when approaching the base of the tail.
The juvenile gradually adopt the adult coloration when they are between 8 and 16 centimeters in length.
Here we go
Japanese Angel fish (Centropyge interrupta)
This is a very rare fish, which has an orange yellow body with violaceous blue spots completed with a bright yellow tail.
The spots are larger towards the tail, and the bottom part of the fish becomes gradually purple. They are native to the Ogasawara Islands in southern Japan.
This angel fish is notoriously difficult to find, and at the same time considered one of the most beautiful and lasting of the Angels fish species.
Flame Angel Fish ( Centropyge Loriculus)
This is one of the species of dwarf angel fish with a more striking livery. Its intense red coloring, decorated with black vertical lines and an electric blue edging on the back of its dorsal and hind fins, makes this species one of the most desirable for all marine aquarium fans.
Emperor AngelFish In Captivity
This little angel fish is a territorial species that will require of enough space to swim and enough caches to achieve its adaptation to captivity. 
The angel fish’ diet is particular since in nature they mostly feed on sponges, which implies a real headache in captivity.
It will depend a little on the individual and its degree of adaptation to the captivity that accepts other type of food, especially bivalves.
Aquariums very equipped with live rock and many invertebrates will benefit their existence.
They can feed on frozen food and pellets but will require patience and detailed follow-up.
The Adult Emperor Angelfish in captivity show maximum sizes of between 20 and 25 cm.
Due to such fact, adults Pomacanthus Imperators shouldn’t be kept in tanks or aquariums lower than 500-700 liters and it’s very recomended to start with juvenile specimens that are well acclimated to captivity.
The frozen Artemia, krill and bivalves such as clams are very recommended foods to facilitate their adaptation to the tank.
However, we will have to be extremely careful with the amounts offered and the abandoned remains so as not to compromise our invertebrate colonies with the nitrate and phosphate peaks because of the unconsumed food.
Keep in mind that nothing creates more debris than an adult angel fish nibbling on a clam.
The lyophilized seaweeds in tweezers with suction cups fixed on the aquarium glass will be much appreciated by the animal.
The Emperador angel fish can be viable in reef aquariums with sessile invertebrates if it is adapted to food and there is a good amount of corals. 
It’s an extremely active fish once acclimated. It is a great swimmer so it requires ample free spaces to move up to the 30 cm that can reach to height.
A community of varied and quiet fish will give you peace of mind and therefore the critical volume of the tank.
The Angels are territorial so our installation should provide them enough space . If our emperor has a structure of living rock enough as a refuge will gradually adapt and will be shown every day for longer.
Water parameters
Water must be provided with the following parameters from 22.2 to 27
Behavior
The Pomacanthus Imperator is the rooster of the corral, therefore will attack other species of angels fish and even butterflies that remind him of his own coloration.
There are many species with very different livery that can share the aquarium with them without a big problem. Fish of the family Acanturídos Acanthuridae (surgeon fish) are suitable, since they are very well armed and the Angel Emperor will not dare to violate them.
Their compatibility with tube worms and coral polyps will depend in part on the individual. No one can guarantee that it is 100% compatible with sessile invertebrate aquariums.
One of the biggest threats for our spectacular specimen are stress situations… Either by the aquatic, decorative or companion conditions in the tank.
The Cryptocarion irritations (marine white spot) and the Oodinium (velvet diseases) are their worst enemies. They will appear when the animal loses the protective mucosa that covers it.
In marine installations with invertebrates we can’t medicate with copper, so we should try to tackle the stressful circumstance to try to cure the ailment
White Spot Treatment
The best procedure is to raise the aquarium’s temperature to about 27 º C, in order to accelerate the life cycle of the parasite. You can then apply the appropriate medications to remove protozoa.
The most used are formalin and malachite green for about 7 days, but there are many others equally effective.
Follow carefully the instructions of each product to avoid intoxications and give a good quality food to the fish to strengthen them.
When using medicines, remove the charcoal from the filter and turn off UV filters.
Also remember to increase the oxygen supply when you raise the water temperature.
Another option is to remove all fish from the aquarium, raise the temperature to 30 º C and let spend about 4 days to make sure that all the protozoa have died.
In this case, you must apply the treatment or completely change the water within 2 days in the tank where the fish have been moved to not reintroduce the disease
How is the white spot prevented?
The most effective way to avoid the white spot is prevention. You must have extreme caution when introducing new fish into the aquarium.
Any new inhabitant must go to a quarantine tank at high temperature (25 º C) for at least 2 weeks. Avoid plants that come from an aquarium with fish without a quarantine of 4 days.
If the disease doesn’ t manifest, you can enter the fish in your aquarium. Take special care about the water quality; don’ t make sudden changes in temperature, pH or ammonia levels. Always use a good quality food for fish, like frozen or dry food and vitamins.
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