japanese swallowtail angelfish

The Ultimate Swallowtail Angelfish Care Guide

The masked swallowtail angelfish is a beautiful fish that can be found in the Caribbean and Atlantic oceans.

They are a popular aquarium fish and can be easily identified by their elegant long body and the two long fins that resemble wings.

These species are hardy and easy to care for, making them a great choice for novice aquarists. 

In this guide, we will discuss everything you need to know about keeping masked swallowtail angelfish in your aquarium.


Scientific NameHolacanthus melanospilos
Common NameBlack-spot angelfish, spotbreast angelfish, Japanese swallowtail angelfish, blackspot lyretail, masked swallowtail angelfish, and zebra angelfish
Care LevelModerate
Size18cm (7.1″)
Lifespan10-15 years
Temperature72 to 78 F
pH8.1 to 8.4
Hardness8 to 12 dGH
Specific Gravity1.020-1.025
OriginWestern Indo-Pacific, Australia
Tank Size125 gallon
Tank LevelAll areas
BreedingEgg scatterer
Reef Tank CompatibilityExcellent – no threat to stony and soft corals
Japanese Swallowtail Angelfish Characteristics

Japanese Swallowtail Angelfish Origin & Habitat

This angelfish is a tropical fish that lives in the islands of Fiji, Indonesia, and Vanuatu in the Pacific Ocean.

This species can be found in deep pools on steep slopes, and they inhabit rocky reefs and coral reefs along the western coast of the Western Pacific: southern Japan, Taiwan, and the northern Philippines.

They are always hanging out in pairs, males and female japanese swallowtail angelfish.

Japanese Swallowtail Angelfish Behavior

Swallowtail Angelfish is a protogynous hermaphrodite, which means that the fish starts life as a female Japanese swallowtail angelfish and will turn into a male at a certain point in their lives.

They live in a harem group, where a group of female Japanese swallowtail angelfish surrounds one male.

If this male dies, one of the females in the group will turn into a male and take over the role.

This fish that turns into a male must be completely colored and able to compete with the other males in the group for dominance. Turning into a male takes up to 30 days to complete.

Japanese Swallowtail Angelfish Features

Masked Swallowtail Angelfish Features
Masked Swallowtail Angelfish Features

1. Appearance

The most immediately noticeable feature of these species is their body shapes.

It is deeply compressed laterally, as are most of its family members. But it is considerably curvier than other angels. It has a well-rounded head, shoulder, and belly taper towards its anterior like a fiery comet.

Both the dorsal and anal fins terminate in rather sharp points. At the same time, the tail is more impressive, more extended, and more lyre-shaped than that of the fish’s genicanthid cousins.

Beyond its crescent-shaped caudal fin, some other notable characteristics are found.

They have small mouths lined with three or four rows of small bristle-like teeth, often with tips that have three points.

But, their teeth are shorter than the rest of the members of the Pomacanthidae family, obviously a reflection of their feeding tactics of picking prey out of the water column versus removing algae from the encrusting rubble.

2. Color

Like other members of the genus, this fish has a high degree of sexual dimorphism (males and females have different colors).


Females have a rich metallic baby blue color that fades gradually towards the rear, with the face being the richest portion.

They also have a thin blue line on their back that runs along the margins of both of their caudal and dorsal fins.

The caudal fin possesses a dark, blue-black edging on top and bottom, conveying a marine-blue hue.


The only color similarities between males and females are the blue background and edging.

Males have a pale orange line bordering the blue edge of their anal and dorsal fin on the left side of their body before breaking into numerous separate spots.

On the back and top of their neck, dark, thin vertical bands stretch across the whole flank and forehead.

The tail edging on them is much faint than the female, fading to silvery grey in between and sporting orange specks that emerge from the bands over the caudal region.

It is also called a blackspot angel fish because of the black spot on the male’s breast.

3. Length

The maximum size of this fish is 18cm (7.1″) long.

4. Lifespan

The Swallowtail Angels have a lifespan of 10-15 years, which means they will provide its keeper with a lifetime of enjoyment.

Japanese Swallowtail Angelfish Cost

Small: over 1.5-2″female$139.99
Medium: over 2-3″male$249.99
Medium: over 2-3″female$149.99
Large: over 3-4.5″male$259.99
Large: over 3-4.5″female$159.9
Japanese Swallowtail Angelfish Cost

How to Care for Japanese Swallowtail Angelfish?

How to Care For Japanese Angelfish
How to Care For Japanese Angelfish

1. Water Parameters

Water Changes

Water Changes are significant as it helps to keep the water quality high and stable.

We recommend doing a 20-30% water change every week to reduce the amount of food wasted and help keep your reef tank clean.

Water Temperature

Masked Swallowtail Angelfish inhabits tropical aquariums with a 72-79 degrees Fahrenheit water temperature range.

So, it’s essential to imitate their natural habitat as closely as possible to keep them healthy and happy.

pH Range

pH range is another crucial factor to consider when caring for these fish.

Ideally, you should maintain a pH level between 8.1 to 8.4 for optimal health.

Ammonia, Nitrite & Nitrate

Angelfish cannot tolerate high ammonia, nitrite, or nitrate levels and will become ill if exposed to them.

So, keeping these toxins as low as possible is essential. Ammonia and nitrite should be kept at 0ppm and nitrate below 20ppm.

Water Movement

To keep your fish happy, provide them with a consistent water movement throughout the day.

We recommend installing a powerhead or using an air pump to create some movement in the water.

Specific gravity

Angelfish can adapt to a wide range of specific gravity levels, so it is essential to keep it between 1.020-and 1.025.

2. Tank Setup

Tank Setup for Masked Swallowtail Angelfish
Tank Setup for Masked Swallowtail Angelfish

Tank Size

The japanese swallowtail angel is smaller than the average angelfish when it reaches full size, measuring around seven inches in length.

It still requires more swimming space, despite its active lifestyle.

A 125-gallon or giant aquarium should be used (some propose providing an even bigger tank).

Tank Lids

Lids are necessary since this fish might attempt to leap out of open aquariums.


Angelfish are messy eaters and will produce a lot of waste. So, a good filter is needed to keep the water clean and ammonia levels low.

We recommend using a canister filter or an overflow box filter.

Hiding Places

Hiding places help to reduce stress and make the fish feel more comfortable.

A good way to provide hiding places is to add plenty of live rock (there will also be many dimly lit places that will assist with the acclimatization process).

Caves and driftwood are also another great way to provide hiding places.

Is Swallowtail Angelfish Hardy?

The Swallowtail Angelfish adapt readily to life in captivity, eating aquarium food and acclimatizing to the conditions present in a properly maintained tank.

This species is only for intermediate to expert aquarium keepers.

Swallowtail Angelfish Diet

Although this angelfish frequently eat diatom and filamentous algal in aquariums, still, you should feed it a balanced diet that includes meaty foods, such as:

  • Frozen silversides
  • Frozen brine
  • Enriched Mysis shrimp
  • Dried seaweed (nori)
  • Enriched flake food
  • Pellets containing spirulina that is suitably sized for angelfish.
  • Live copepods
  • Amphipods
  • Special sponge-based Angelfish preparations,
  • Finely chopped krill/squid/cockle/mussel.

Just make sure to provide them with small quantities of food three times a day.

Swallowtail Angelfish compatibility

Blackspot Angelfish Compatibility
Blackspot Angelfish Compatibility

Swallowtail fish are generally peaceful and will only attack small, peaceful planktivores such as Anthias fish if provoked.

Such aggressive fish so carefully avoid mixing swallowtail angelfish with other more aggressive fish as they may overpower your angels.

Triggerfish, large angelfishes, and most surgeonfishes are some of the more aggressive fish.

In addition, males from their species, other Genicanthus genus males, and fish with similar coloration will fight.

As a result, keeping this fish as a mated pair or collecting a tiny number of females with one male in many aquariums may be preferable.

Although we will usually overlook some of the less aggressive dwarf angelfish from the Centropyge genus, do pay attention to each fish as an individual because behavior is not always set in stone.

Possible tankmates include:

  • Clownfish
  • Blennies
  • Gobies
  • Chromis
  • Butterflyfish
  • Small lionfish
  • Eels
  • Anthias fish.

Is Swallowtail Angelfish Reef Safe?

Swallowtail Angelfish Reef Safe
Swallowtail Angelfish Reef Safe

The swallowtail angelfish is one of the few truly reef tank-safe angelfish because it does not harm other types of corals or sessile invertebrates.

They’ll go after small planktivores like wreckfish (Pseudanthias spp.), fairy and flasher wrasses, and firefish in the reef tanks, but they’re entirely harmless with soft or rocky corals.

Furthermore, the swallowtail angelfish is a midwater column animal, indicating that it does not exist in nature on the reef tank or near the surface.

Swallowtail Angelfish Breeding

Males use a variety of motions or fin gestures to entice females to mate.

In the case of male swallowtail angelfish, they turn on their sides or backs in front of females, positioning themselves directly in front of the female and quivering or vibrating their caudal fin.

If the male succeeds in his first attempts, the mating ritual continues. The male’s entire body will shake or quiver ecstatically while positioned alongside the female.

The female then spreads her dorsal and anal fins as encouragement.

After a few seconds of the male nuzzling his head near the female’s rump, the pair broke apart only a few inches.

They lay their eggs and sperm on the ground, after which the male vigorously guards them.

Incubation of eggs and larvae is 8-12 days, after which the fry is free-swimming.

Last Words

The Swallowtail Angelfish is a beautiful addition to any saltwater aquarium. They will thrive in your reef tank and bring years of enjoyment with proper care.

As with all fish, do your research before adding them to your tank to ensure compatibility with your other fish.

If you have any questions, feel free to leave them in the comments below.