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The Emperor Angelfish – King Of Your Saltwater Aquarium

If you are looking for a fish that is not only vibrantly colored but also elegant, the Emperor Angelfish is the best fish for your saltwater aquarium..

A hardy fish species, this graceful fish is often the prized possession of a saltwater tank. It is best kept by experienced fish keepers, as it can grow quite large and needs pretty specific water conditions. It’s also relatively expensive, making it a good option only for aquarium hobbyists who have plenty of time to devote to it.

Ready to learn more about this regal fish? Here’s everything you need to know to raise the Emperor Angelfish.

Emperor Angelfish

Emperor Angelfish Background

Emperor Angelfish 4
Photo by Joe Martin

An absolutely stunning saltwater fish, the Emperor Angelfish is just one of many Angelfish commonly kept by aquarium hobbyists. First discovered in 1787, this fish goes by the scientific name of Pomacanthus Imperator. It is native to the Indo Pacific Ocean and is part of the Pomacanthidae family.

If you hear it being called by other names, don’t be confused – this fish is often referred to as the Imperial Angelfish and the Imperator Angelfish. Interestingly, up until 1933, this fish was believed to be another fish species altogether – the Pomacanthus Nicobariensis. No matter what you call it, though, this fish is one you must consider raising if you have some experience in raising saltwater fish.

Emperor Angelfish are often mistaken for Koran Angelfish in their juvenile stage. You can tell them apart, however, because the Koran Angelfish will have a white strip that makes a circle shape instead of a C shape. They also do not have the same pattern on the anal and dorsal fins.

When you purchase an Emperor Angelfish, do so with attention to her fish’s health and wellbeing. This fish do not hold up well to the stress of transport, so you will want to make sure you select a fish that appears to be in good health. Select a juvenile that is around five inches long, as this is the ideal size for adapting best to captive conditions. Your fish should be active and curious, not behaving in a lethargic or disinterested manner.

You should also check the gill count to make sure it’s less than 80 a minute. This is not a good sign if it is higher than that, particularly if the fish is swimming calmly and has no reason to have a higher gill count. In addition, you will want to make sure the fish isn’t too bright or disorientated acting. While you want an Emperor Angelfish that is vibrantly colored, one that is overly so yet displaying lethargic behavior has likely been treated with cyanide.

Emperor Angelfish Appearance And Behavior

Emperor Angelfish 5
Photo by Zsispeo

Emperor Angelfish are unique in that they experience three different life stages in which each its appearance drastically changes. As a juvenile, the Emperor Angelfish will have a different appearance than it will as an adult. Young Emperor Angelfish have black bodies with pale whit and blue vertical lines on the face. The body itself will have three curved white bands, each of which is relatively wide and extends from the anal fin to the dorsal fin. The second looks like a “C” and the third will be close to the tail fin.

Between each white curve is a thinner, pale blue curve. Both anal and dorsal fins are comprised of black hexagonal markings, each of which also has pale blue trim. The dorsal fin, too, is tipped in white.

Later in its life, the fish will develop some yellow patterns on its tail. It may also have vertical yellow lines on its body, which will become rounder as the fish ages. Once it’s fully developed, the Emperor Angelfish will have a white snout and mouth, s well as dorsal fins with white edging. It will have an exceptionally deep body with blue and yellow stripes, as well as a mask-like black band around its eyes.

It can take some time for the Emperor Angelfish to go through the full extent of these changes. In some cases, it can take up to two years, all of this happening while the fish is only about three or four inches in length. Sometimes, the color changes can take longer than this, as the process is delayed by being confined to captivity.

Angelfish usually grow up to lengths of 15 inches in the wild, but in captivity, they are far less likely to grow that large. They will usually only reach a foot or so when raised in your home aquarium.

Emperor Angelfish live in the reef environment of the Indo-Pacific ocean. As juveniles, these fish prefer to live alone, hanging out in rockwork near the outer edges of the reef. There, young Emperor Angelfish occasionally venture out to act as cleaner fish. Adults, on the other hand, will spend their days in seaward reefs, channels, and rich coral environments of clear lagoons.

Males can be somewhat territorial, claiming dominion over a large territory – up to 10,000 square feet! – that they will share with two or more female Emperor Angelfish.

Emperor Angelfish Tank And Water Requirements

Emperor Angelfish 6
Photo by Zsispeo

Replicating the home environment of the Emperor Angelfish is important when you are setting up your saltwater tank. This will help your Emperor Angelfish feel most at home and will prevent any health issues from coming up.

You will need an exceptionally large tank for your Emperor Angelfish – think no smaller than 125 gallons for a juvenile and 180 gallons for a breeding pair. You will need to include lots of live rock, which the fish will graze on. The rock also serves as hiding spots to help the angelfish feel more comfortable.

Don’t think you can just fill a small tank with tons of rock and be good to go, however. In addition to these decorations, your Emperor Angelfish will also need lots of open swimming space. They don’t like being confined.

Your tank should be warm, kept at temperatures between 72- and 82-degrees Fahrenheit. The pH should be between 8.1 and 8.4 and the tank should have a specific gravity of 1.023-1.025. Emperor Angelfish can get by fine with most types of water current, but they usually prefer waters that are slow-moving. A good filter is also recommended.

Captive Emperor Angelfish often don’t grow to be as brightly colored as their wild relatives. This is because they need lots of light and if they don’t have that, they won’t express their colors as well. Provide tons of light, and make sure it is natural light whenever possible. Not only will this help the Emperor Angelfish express its colors more vibrantly, but it will also prevent certain diseases like Head and Lateral Line Erosion Disease.

Like many fish, Emperor Angelfish put a significant bio-load on the aquarium. You should make sure you have a fully cycled tank and that it has been set up for at least six months before you decide to introduce any Angelfish. Conduct regular water changes to keep your water clean, and make sure you stay on top of any potential water condition issues.

You should change about fifteen percent of the water every two weeks. If you only clean once a month, double that amount. In addition, a tank that has corals in it will need to be cleaned at as slightly lower ratio – you should remove only 10 percent every two weeks or even better, five percent once a week.

It can be difficult to keep Emperor Angelfish with most corals, as they have a tendency to nip soft and stony corals. They can be kept with small-polyped stony corals, however, like star polyps and bubble corals.

What Do Emperor Angelfish Eat?

Emperor Angelfish 7
Photo by Tullio 1940

It can be tough to feed an Emperor Angelfish. These fish are finicky when they are first introduced to a tank, and may even refuse to eat. This is why it’s important that you put new Emperor Angelfish in a tank that has already been established so that they can eat comfortably while they are getting used to the tank.

When you first introduce them to this tank, you will want to feed them small amounts, but often – up to 5 times each day. Emperor Angelfish are omnivores, eating both plant and meat matter, and will need a balanced diet of meaty materials, vegetable foods, and sponge material in order to stay healthy.

You will not be able to exactly replicate the diet they have in the wild. Emperor Angelfish eat so many different types of unique foods, like tunicates, bryozoans, algae, and hydroids, that you won’t be able to find these for your tank. In addition, continuously replenishing your tanks will become extremely expensive.

Instead, mimic the natural diet as closely as possible by feeding nutritious foods like frozen food, live food, algae, spirulina, and formula food. They will often eat meat and vegetables, like scallops, chopped squid, and shrimp. You can even make your own food to make sure your fish get the most nutritious diet. Some good options might be spinach or mussels.

Once they’ve gotten used to their new home, your Emperor Angelfish should be fed small portions three times a day. Watch them carefully as they eat and remove any food that they do not consume within five minutes. This will prevent your fish tank from becoming contaminated with food particles.

Emperor Angelfish Tank Mates

Emperor Angelfish 1
Photo by Stephane Bailliez

Emperor Angelfish can sometimes be aggressive toward other fish – particularly toward angelfish that are of a similar shape or color pattern. You can often keep other Angelfish with an Emperor Angelfish, but you need to make sure they don’t look too much alike.

Make sure the juvenile Emperor Angelfish is the last fish you introduce to the tank, as this will reduce the likelihood of territorial behavior. Usually, small, peaceful fish are prone to being harassed by this fish species, although they will get along well with larger saltwater fish that are not shaped like angelfish.

Avoid any fish that are small enough for your Emperor Angelfish to eat – this can and will happen. Remember that although the Emperor Angelfish might be a little bit shy when you first introduce it, it will warm up quickly and become a very active, outgoing fish. These fish are quite fun to watch – you may even notice them making unique grunting sounds if they get too close to other species in your saltwater tank!

Common Emperor Angelfish Diseases

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Photo by Tamy Thanh

Like all other saltwater angelfish, Emperor Angelfish are prone to certain diseases that typically affect captive saltwater environments. Often, these conditions are brought on or exacerbated by inappropriate housing or unsuitable tank mates. Some of the most common diseases are White Spot Disease, and Marine Velvet.

White Spot Diseases, also known as Ich, is one of the most common disease to affect saltwater and freshwater fish species alike. It results in a fish constantly scratching itself, having lots of small white dots all over its body. You can treat and prevent this disease by ensuring good water quality. However, left untreated, it can result in the suffocation of the fish as the parasites will block the gills and prevent them from providing oxygen to the rest of the body.

Marine Velvet is also common. This is a parasitic skin flagellate and causing the cells of the fish to appear to be covered in a pepper-like coating. This can cause serious respiratory distress and clamped fins. You might also notice that your fish has lost weight.

Marine parasites can be presented by keeping your tank clean, and if you notice that you have a problem with parasites, you can gradually raise the temperature of your tank by a few degrees. This will inhibit the ability of the parasite to complete its life cycle and to attach to the fish. You may also need to provide medicated food.

Breeding And Life Spans Of Emperor Angelfish

Emperor Angelfish 3
Photo by John Diving

Emperor Angelfish cannot be bred in captivity at this time. People who have tried have not been successful, as successful breeding can typically only be conducted in a large display aquarium. Most home aquarium hobbyists simply won’t have the resources necessary to encourage spawning.

In the wild, the Emperor Angelfish spawns once a year. In most areas, this is in the late summer and early fall. Males will have two or more females that he breeds, with each female having her own territory. It is suspected that these fish mate higher in the water column, circling repeatedly before releasing their eggs and sperm. The larvae float like plankton for a while before turning into fry.

Emperor Angelfish can have life spans of over 20 years in captivity! Therefore, keeping one of these fish is not ideal for someone who isn’t sure they want to continue raising fish for that long. In addition, these fish can be somewhat difficult to raise, as they need very specific water parameters as well as an exceptionally large tank.

These fish are popular and in high demand. Because of that, they come with a steep price tag.

Is An Emperor Angelfish For You?

Emperor Angelfish are gorgeous fish that can add some extra beauty to your saltwater aquarium. Although you should have some experience in raising saltwater fish before attempting to raise one of these illustrious beauties, if you have been raising fish for a while you are probably ready to tackle this challenge.

These fish can be difficult to raise, requiring pristine water conditions and certain tankmates in order to thrive. However, in most cases, the extra considerations will be well worth it, as this fish lives for quite some time and can add instant attraction to your saltwater tank environment.

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