Emperor Angelfish are gorgeous saltwater fish that stand out in any tank. Because of their looks, this popular species is on the shortlist for many aquarists.

However, caring for them requires you to have a strong understanding of their basics needs. Keeping these fish in a home aquarium is not a walk in the park.

This guide will go over all the fundamentals of Emperor Angelfish care to make you ready for ownership. You’ll also learn some helpful facts that will make you appreciate this species even more!

Species Summary

A favorite among nature photographers, the Emperor Angelfish (scientific name: Pomacanthus imperator) is one of the most recognizable fish in the world.

First discovered in the late 1700s, this fish has been heavily featured in everything from magazines to television shows. It’s not hard to see why!

Thanks to its bright coloration, the Emperor Angelfish is an instant head-turner. They’re often the shining star of coral-laden aquariums the world over. You might also see them labeled as Imperial or Imperator Angelfish.

Side view of an Emperor Angelfish

The natural distribution of this fish is vast. They’re native to the Indo Pacific ocean, spreading from East Africa to New Calcedonia. Despite their popularity, wild populations are still going strong.

Moderately difficult to care for, these fish demand attention and will be the center of attention in your saltwater tank!

Emperor Angelfish Lifespan

The average Emperor Angelfish lifespan is over 20 years in captivity. They have been known to live even longer in the wild.

While you can expect to have your fish for a couple of decades, there are no guarantees! These fish are very sensitive to water conditions and are prone to getting sick if tank conditions don’t meet their needs.

To avoid all of this and give them the longest life expectancy possible, you have to continually work to maintain their needs.

Appearance

While many fish species go through physical changes as they grow, none are quite as dramatic as the Emperor Angelfish. Juveniles and adults are significantly different in appearance. In fact, scientists thought that juveniles were a completely different species until the late 1930s!

Juveniles have a black body that’s covered in C-shaped bands. They typically have three thick bands of white. Separating those white bands are thinner bands of sapphire blue.

Author Note: The face has the same striping pattern. However, the fins are a little different. They take on a blue scale-like pattern. The fins are also edged in white.

As the fish gets a bit older, they enter the sub-adult stage of their life. During a two-year period, their appearance will slowly transform into that of a full-grown adult!

Adults have horizontal stripes of blue and yellow. The stripes start at the gills and stop just shy of the tail. The area in front of the gills is very unique. These fish have a mask-like band of black that covers the eyes.

It’s edged in sapphire blue, giving the fish a very distinct look. The snout and mouth are pure white.

Pomacanthus imperator swimming in a saltwater aquarium

The bottom portion of the fish is black as well. Though the separation of colors is less distinct. A thick black band covers the gills and pectoral fin. The black color then stretches down to the anal fin to create a nice gradient.

The fins of the Emperor Angelfish are unique, too. For both juveniles and adults, they’re rounded and blend in with the body of the fish to create a uniform shape. For adults, the tail is yellow while the dorsal fin has a highlighting stripe of white.

The interesting thing about sub-adult Emperor Angelfish is that the transformation is observable! You might see half of your fish’s body with the adult coloration while the other half still has the juvenile coloration.

Average Size

In the open ocean, Emperor Angelfish can reach lengths of about 15 inches. However, it’s rare for captive fish to get that big.

Author Note: Most captive specimens will hover around 12 inches when fully grown.

If you want these fish to get as large as possible it’s important to provide them with the best care you can. Have a plan from day 1 and stay consistent to help them while they’re still growing.

Emperor Angelfish Care

Emperor Angelfish care is no easy task. In the wild, these fish can live at depths of over 300 feet. Plus, they live in biologically rich habitats.

This means recreating a similar environment in a saltwater aquarium at home can be tough.

That said, it’s definitely possible with a bit of know-how. Below are some care guidelines to help you get things right!

Tank Size

Emperor Angelfish are quite territorial. In the wild, they are known to have territories as large as 10,000 square feet. Obviously, that’s not possible in a home aquarium. But, you do need to provide ample space to help the fish thrive.

It’s recommended that you keep juveniles in tanks that can hold at least 125 gallons. If you plan on keeping a pair, bump that volume up to at least 180 gallons.

Adults will need even more room. Fully-grown Emperor Angelfish should live in tanks no smaller than 220 gallons.

Author Note: As always, if you can provide them with an even larger tank this species will be even happier. Extra space is never a bad thing!

Water Parameters

When you’re setting up your saltwater tank, you need to replicate natural ocean environments as much as possible. Emperor Angelfish will often respond negatively to conditions that are significantly (or even slightly) different than what they’re used to.

First, the aquarium should be set up several months before adding the fish. This helps to create sufficient biological growth while stabilizing the conditions.

Cycling your tank for a minimum of six months is ideal.

Here are water parameters to shoot for while you’re preparing your Emperor Angelfish’s new home.

  • Water temperature: 72°F to 82°F degrees (somewhere in the middle of this range is ideal)
  • pH levels: 8.1 to 8.4
  • Water hardness: 8 to 12 dKH
  • Specific gravity: 1.020 to 1.025 (around 1.023 is best)

Perform regular water tests to be sure these parameters are stable before introducing your Emperor Angelfish to their new home. These are not fish where you can adjust on the fly. Do whatever you can to get things right the first time!

How To Set Up Their Tank

Emperor Angelfish tend to move to different environments as they age. However, one constant is that they’ll usually stay close to reefs. With this in mind, you should design your tank accordingly.

One essential item is live rock. Live rocks act as a food source for the Emperor Angelfish. They’ll also use it to hide.

Plenty of coral is good, too. But, you have to be careful about the types of coral you introduce to the tank. This species is known to feed on stony and soft coral. Your best bet would be to add small-polyed stony corals, bubble corals, disc anemone, hammer corals, and star polyps.

Don’t go overboard with the rock and coral. Your fish will need a lot of it to thrive. However, they also need ample swimming space in the tank.

Author Note: A strong filtration system is required for the tank. These fish produce a lot of waste. So, the filter should be efficient enough to cycle the tank and regulate levels.

Other things you should consider are flow and lighting. Emperor Angelfish will tolerate any flow level. But, they prefer slow-moving water.

Strong lighting is recommended for this species. Not only does it help to bring out their coloration, but it can also help you avoid disease (more on that later).

Disease Potential

Unfortunately, Emperor Angelfish are at risk of experiencing several diseases. The most common are Ich, Marine Velvet, and Head and Lateral Line Erosion Disease.

If you have some experience with either marine or tropical fish, you know what Ich is! Also known as White Spot Disease, this condition is caused by an external parasite. It’s highly contagious and can be fatal if left untreated.

Marine Velvet is another parasitic disease. When infected, skin flagellate covers the body in gold-colored spots. It’s reminiscent of velvet fabric, hence the name.

Finally, there’s Head and Lateral Line Erosion Disease, also know as HLLE or Hole-in-Head Disease. The exact cause of this disease isn’t definitive, but it’s theorized that providing Emperor Angelfish with a lot of light can help avoid it.

The best way to avoid any of these diseases is to stay on top of tank conditions. Stress or parasites in the water will trigger the disease. Maintaining conditions and keeping the fish happy can prevent serious health issues.

Perform a 15 percent water change every two weeks. If you have coral in the tank, only do 10 percent changes to avoid harm.

Food & Diet

Emperor Angelfish are omnivores. In the wild, they’re considered cleaner fish and eat pretty much anything they can find in the environment.

One Emperor Angelfish swimming and looking for food

When you first introduce the fish to the tank, they’ll probably be reluctant to eat. During the first few weeks, allow them to find food on the live rock. This is another reason why having an established tank comes in handy!

After that, you can slowly introduce food into the tank. Emperor Angelfish enjoy foods like Spirulina, algae, and commercial marine fish food. You can also create custom meals with live or frozen foods.

Shrimp, chopped scallop, and pieces of squid are all favorites when it comes to protein. For plant-based foods, you can try spinach and marine algae.

During the first few weeks of being in your aquarium, feed the fish about five small meals a day. Then, slowly transition to three meals.

Author Note: Only provide enough food that the fish can consume in five minutes. Then, remove any stray food to maintain the water quality.

Behavior & Temperament

These fish are very territorial and semi-aggressive. Males tend to battle for territory, so be wary about keeping two of them together in the same tank.

The same goes for any smaller fish. Despite their beauty, Emperor Angelfish can be bullies to smaller fish. They’re even known to bully other Angelfish or any species with a similar profile.

At first, your Emperor Angelfish may be quite shy in the new environment. They may spend more time hiding than scavenging for food.

However, that all changes once they acclimate.

Once comfortable, you can spot your fish searching for food and exploring. They’re very active in the right conditions. They’ll get more confident with time. Eventually, they’ll start holding their ground.

If you hear a strange grunting noise, don’t be alarmed. That’s just what Emperor Angelfish do when they feel threatened!

Tank Mates

Due to their semi-aggressive nature, you have to be extra cautious about tank mates. Generally, it’s best to introduce Emperor Angelfish last in a community tank. This can help reduce the chance of them displaying territorial behavior.

You can keep a bonded pair of Emperor Angelfish together. Even two females and one male is often fine. But, you should avoid placing two males together.

The same goes with other angelfish with similar color patterns. As long as the angelfish isn’t too visually similar, there shouldn’t be any problems.

For the most part, Emperor Angelfish do well with other large saltwater species. Various species of Tang fish are a favorite tank mate for Emperor Angelfish. Avoid any smaller fish to avoid predatory behavior.

Breeding

Breeding Emperor Angelfish is very difficult in captivity. It’s possible in massive environments, but, breeding in home aquariums is nearly impossible due to the specific conditions these fish require.

In the wild, they usually only spawn during a short period late in the year. When they’re ready to spawn, the male and female will rise close to the surface of the water. The female will then distribute her eggs in the strong current where they will drift to safety.

This just isn’t possible in a home aquarium setup. As a result, bonded pairs will rarely attempt to spawn.

If there’s a breakthrough and someone discovers a consistently successful breeding technique for this species we’ll be sure to update this guide. Until then, our recommendation is to avoid trying at all (even if it’s just for fun).

Up To The Task?

Now that you’ve read the guide, it’s time to decide if you’re ready to do what’s necessary to provide excellent Emperor Angelfish care.

You see, understanding what it takes to own these fish isn’t what’s difficult. What makes it hard is actually following through and doing the work.

If you have enough space for a large saltwater tank (and all the equipment that goes with it) and are willing to cycle the tank for a while before buying, go for it!

These fish are a joy to own and the beauty they’ll bring to your aquarium is incredibly unique. Trust us, you’ll spend hours watching them swim.

If you have any questions about the facts or recommendations we covered in this care guide feel free to contact us. We’re always happy to help!

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