Swallowtail Angelfish Care (And Some Interesting Facts)

Swallowtail Angelfish Care (And Some Interesting Facts)

Masked swallowtail angelfish

Swallowtail angelfish is the most graceful reef-dwelling marine fish species. These brightly colored fish are a true beauty to behold.

They’re popular with both new and seasoned aquarists.

However, fishkeepers need to keep the tank conditions within the recommended range for these fish to thrive.

Let’s learn about swallowtail angelfish in more detail.

Swallowtail Angelfish Species Overview

Swallowtail angelfish, also known as spotbreast angelfish or blackspot angelfish, inhabit the waters of the eastern Indian Ocean and the western Pacific Ocean.

These fish occupy areas rich in coral on the outer slopes of reefs.

Swallowtails live in small groups consisting of a male and several females.

Like other angelfish, swallowtail angelfish is a protogynous hermaphrodite, which means all fish start as females, and the dominant fish changes to male.


Swallowtail angels show gender dimorphism. This means males and females have distinct appearances.

However, in both genders, the forked tail narrows at its base to form a “swallow tail.”

Males are blueish white with dark red vertical stripes and yellow spots on their dorsal, caudal, and anal fins.

The caudal fin has a lighter shade, with blue margins and long filamentous lobes.

In females, the dorsal side of the body is yellowish, and the ventral side is blueish white.

Their tails are bluish, with a black line running down the lower and upper edges.


Swallowtail angelfish have a life expectancy of 10 to 15 years.

However, they must get proper water conditions and a well-balanced diet to improve their lifespan.

This fish species is suitable for intermediate to advanced aquarium owners.

New aquarium owners can have challenges in handling this saltwater fish.

Average Size

In the wild, swallowtail angelfish reaches a maximum length of 8.7 inches.

However, the average size of a fully grown swallowtail angel in a marine aquarium is up to 7 inches.

Females are slightly smaller than males. Moreover, the size difference between males and females isn’t too significant.

Swallowtail angelfish are small but prefer plenty of space inside the aquarium.

So ensure that they get the required space to move around the tank.

Swallowtail Angelfish Tank Setup

Swallowtail angelfish have an easy-going nature and quickly acclimate to the tank conditions.

However, these fish need ample swimming space.

So let’s understand how to set up the fish tank for swallowtail angelfish.

Tank Size

Swallowtail angelfish are active swimmers and love to move around the tank.

Therefore, a large aquarium of 100 gallons or more capacity is a good option for these fish.

Small tanks restrict their movement and result in aggressive behavior.

These fish become territorial in the absence of enough space. So large tanks are recommended for them.

The tank should also be designed to have visual barriers.

So create hiding places and shelter areas that break up the line of sight of these angelfish and curb their aggressive tendencies.

Tank Equipment and Decorations

Swallowtail angelfish are one of the angelfish species that are genuinely safe for reef tanks.

It means these fish will not bother corals or other invertebrates inside the marine aquarium.

These fish need consistent water movement, so an air pump must be installed inside the tank.

A filtration system is also required because these angelfish are messy and produce a lot of waste.

You can add coral reefs to create a natural environment.

Live rocks, caves, and driftwood must also be added to create hiding places inside the aquarium.

The tank must be secured by a lid, as swallowtails can attempt to leap out of the tank.

Moderate to dim lighting is best to create an environment similar to their natural habitat.

Given below are the items required in a swallowtail angelfish tank:

  • Substrate (gravel or sand),
  • Air Pump,
  • Filter,
  • Heater,
  • Moderate Lighting,
  • Aquatic plants,
  • Thermometer,
  • PH testing kit, and
  • Hiding places like live rocks, caves, driftwood, etc.

Maintenance is essential to ensure that the water parameters remain within the desired range.

This will avoid any sudden spike in ammonia, nitrite, or nitrates inside the tank.

Swallowtail Angelfish Care

Swallowtail angelfish are popular species that quickly adjust to a captive environment.

However, proper care and attention are essential for their optimum growth.


Swallowtail angelfish are planktivores that primarily feed on planktonic, including zooplankton and phytoplankton.

These fish mostly graze on the outer slopes of the reef.

They often consume diatom and filamentous algae in marine aquariums.

However, feeding them meaty food is essential to satisfy their protein requirement.

Feed them finely chopped fresh or frozen shrimp and frozen silversides.

Also, serve them marine algae, spirulina, and algae-based flakes or pellets.

You should feed them a small amount of food at least three times a day.

Young fish must be fed at least 4 times daily to support their growth.

Don’t forget to remove the leftover food and waste to control the toxic buildup.

Some of the live food that you must feed swallowtail angelfish are:

  • Brineshrimp,
  • Mysis shrimp,
  • Copepods,
  • Cockle,
  • Krill,
  • Mussels, and
  • Squid.

Feed them only the amount of food that they can eat within a couple of minutes.

You should include both plant-based and animal-based foods in their diet.

Water Parameters

Although swallowtail angelfish adjust pretty well to captive life, keeping the tank water quality high and stable is essential.

They prefer warmer temperatures since they belong to the warm tropi­cal waters.

It’s best to mimic water conditions that resemble their natural habitat.

The ideal water parameters for swallowtail angelfish are:

Water Temperature72°F to 78°F (22°C to 26°C)
Water pH8.0 to 8.4
Specific Gravity (Salinity)1.020 to 1.025
Water Hardness (dGH)8 to 12

Tank Maintenance

You can keep swallowtail angelfish in an aquarium without any special care.

They eat aquarium food and adjust well to its environment.

You should perform a 20 to 30 percent water change every week to prevent waste and maintain a healthy environment for your fish.

Swallowtails can’t tolerate high levels of ammonia, nitrite, or nitrates and will become sick if exposed for a long time.

Therefore, it’s important to keep toxins as low as possible.

Common Diseases

Like other saltwater fish species, swallowtail angelfish can handle changing water conditions.

However, constant exposure to various pathogens can break down their strong immune system.

Given below are a few of the common diseases that affect swallowtail angelfish:

  • Saltwater Ich,
  • White Spot,
  • Marine Velvet,
  • Hole in the head,
  • Fungal infections, and
  • Bacterial infections.

It’s essential to test the water parameters consistently to determine the required maintenance cycle and ensure consistent water conditions.

Swallowtail Angelfish Behavior and Temperament

Swallowtail angelfish is one of the angelfish species that doesn’t nibble on coral.

So it’s a good choice for reef aquariums because it won’t damage the coral.

These angelfish are peaceful and easily cohabitate with other tankmates.

However, make sure they’re well fed to avoid competition and aggression.

The tank size and available space are two of the most important factors when housing swallowtail angels.

Medium-sized or large aquariums help to keep their aggression at bay.

Also, large, aggressive fish stresses your angels, but keeping them with small, docile fish instills their bullying tendencies.

Swallowtail Angelfish Tankmates

Swallowtail angelfish are peaceful fish but show aggressive behavior in certain situations.

So make sure they feel safe and comfortable inside the aquarium.

Swallowtail angelfish are compatible with other fish species that display similar temperaments.

That’s why it’s essential to keep them with like-minded tankmates.

Some of the tankmates that you can keep with swallowtail angelfish are:

  • Anthias,
  • Blennies,
  • Butterflyfish,
  • Chromis,
  • Clownfish,
  • Dwarf Lionfish,
  • Gobies,
  • Tangs, and
  • Wrasses.

Avoid keeping swallowtails with small and docile planktivores because these angelfish chase and bully them.

Similarly, large planktivores can harass your swallowtail angelfish.

Also, avoid keeping them with large, aggressive fish because they will get dominated by the large aggressors.

Given below are some fish that you shouldn’t keep with swallowtail angelfish:

  • Swallowtail angelfish (Multiple male fish),
  • Large Angelfish,
  • Triggerfish, and
  • Surgeonfish.

Swallowtail angelfish can live with other fish species similar to their size and temperament.

However, ensure that there is a lot of space and visual barriers inside the tank for their peaceful co-existence.

Breeding Swallowtail Angelfish

Breeding swallowtail angelfish are challenging. You will have to create an environment that is conducive to breeding.

You will also have to keep these angelfish well-fed by providing a protein-rich diet.

For mating, the male angelfish will start swimming sideways to place its side or back in front of the female or position itself in front of the female, followed by quivering or vibrating its caudal fins.

These body movements or fin gestures are aimed at attracting the female angelfish.

If successful, the male will continue the mating ritual by shaking its entire body in excitement.

The female will then stretch out all of her fins as an indication of encouragement.

The male angelfish will nuzzle his head for a few seconds near the female’s rump.

The pair will turn onto their sides and release their eggs and sperm on the ground.

The male fish will vigorously guard the eggs against any approaching fish inside the tank.

The eggs will hatch in the next 8 to 12 days, depending on the water temperature.

Feed the fry with microalgae to give them the required nutrition.

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