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Watanabe Angelfish

The Watanabe Angelfish is a unique specimen that is sure to turn heads.

This beautiful fish has iridescent blue and black stripes that shimmer in the light, adding a touch of elegance to any tank.

These fish that are native to the Pacific Ocean are known for being peaceful, making them a perfect addition to any community aquarium.

In this guide, we will go over everything you need to know about keeping Watanabe Angelfish in your own home aquarium. 


Scientific NameGenicanthus Watanabe
Common NamesWatanabe’s Lyretail Angelfish and Blackedged Angel
Speciesmarine ray-finned fish
Care LevelModerate
Aquarist Experience LevelExpert
Color FormOrange, Blue, White
Lifespan2-5 years
pH8.1 – 8.4
Water HardnessdKH 8 to 12
Aquarium HardnessDifficult to acclimate
Specific Gravity1.020-1.025
OriginPitcairn and the Society Islands
Minimum Tank Size125 gallons
Aquarium TypeDeepwater Reef
Lightingdimly-lit tank
Aquarium CompatibilitySafe
Watanabe Angelfish Characteristics

Watanabe Angelfish Origin & Habitat

The Genicanthus Watanabe are native to the Pacific Ocean. They range from Taiwan to the Cook Islands and the Tuamotu Archipelago, north to the Ryukyu Islands, south to New Caledonia, and the Austral Islands.

Juveniles sometimes are found on the Great Barrier Reef in the south of Sydney.

Genicanthus Watanabe occurs at depths between 12 and 81 meters (39 and 266 ft), and they are often found around the bases of reefs and on falls where there is a powerful current.

History of Watanabe Angelfish

The Japanese ichthyologists Fujio Yasuda and Yoshiaki Tominaga initially described Genicanthus Watanabe in 1970 from specimens collected at Onna Beach in Okinawa.

The specific name refers to Masao Watanabe, a Japanese ichthyologist from Waseda University in Tokyo, who first discovered the angelfish types but identified them as Genicanthus caudovittatus.

Watanabe Angelfish Behavior

Like all of its congeners, the Watanabe angelfish is a protogynous hermaphrodite that starts life as a female and may change into a male.

When kept in small groups or harems, the dominant female will frequently become a male. The process will usually take between 20 and 40 days to finish.

They have a lek mating system, in which competing males congregate to display and court one another in an effort to entice visiting females who are looking for partners to mate

The male’s mating display begins when the females are ready to mate. He swims on his sides and vibrates his fins to entice them.

Then, the larger and more dominant males choose to have sexual intercourse with the younger females.

Watanabe Angelfish Features

1. Appearance

They are somewhat unusual-looking fish, and their eyes appear to be filled with fluid like a Celestial Eye.

A broad submarginal band runs down the dorsal and anal fins in both males and females and on the lobes of the caudal fin.

The forked tail of both genders becomes a “swallowtail” as it narrows at its base.

2. Color

The color and pattern of Genicanthus Watanabe, like the other angelfishes in the genus Genicanthus, are different between males and females.


The female is an iridescent pale blue with a dark vertical fin and no stripes other than a dark rim around the dorsal and anal fins.

They also have big black bars across their heads and a black spot on the snout.

The dorsal fin has 15-16 spines and 15-16 soft rays, whereas the anal fin has three spines and 14-17 soft rays.

Besides, Juveniles have a lot of the same color characteristics as females.


The male has an iridescent, pale blue body. The lower part of the body and anal fin are highlighted by long, horizontal dark lines that run down its length and one horizontal orange stripe extending toward the tail.

The upper third of their bodies are black, with eight horizontal, thin black stripes and a patch of yellow at the end of the highest.

3. Length

The Watanabe Angel is one of the smallest “Swallowtail” angels, rarely growing more than six inches long. 

4. Lifespan

Watanabe Angelfishes die quickly on most occasions, as their lifespan ranges between 2 to 5 years.

Watanabe Angelfish Cost

In the aquarium trade, Genicanthus Watanabe is not that popular.

Most of the specimens that enter commerce originate from the Philippines and Melanesia.

However, you can obtain them at affordable prices from importers, wholesalers, merchants, and collectors of deepwater fish.

Watanabe Angelfish Cost

3.25 – 4.25 inchesfemale$433.99
1.5 – 2.25 inchesfemale$216.99
2.25 – 3.25 inchesfemale$229.99
3.25 – 4.25 inchesfemale$235.99
5.25 – 6.25 inchesfemale$272.99
1.5 – 2.25 inchesfemale$278.99
2.25 – 3.25 inchesfemale$294.99
4.25 – 5.25 inchesfemale$464.99
3.25 – 4.25 inchesmale$402.99
4.25 – 5.25 inchesmale$681.99
5.25 – 6.25 inchesmale$774.99
Watanabe Angelfish Cost

How to Care for Angelfish?

1. Water Parameters

Water Changes

Keeping the optimal situation for Wanatabe Angelfish necessitates maintaining the ideal environment, which implies cleaning your aquarium once a week.

Depending on your tank’s stock levels and bio-load, we recommend conducting 15-20% water changes every week.

Water Temperature

The Wanatabe Angelfish has a tropical background, and therefore they require warm water.

We recommend a water temperature between 72 and 78 degrees Fahrenheit to help your fish feel comfortable and at home.

pH Range

The Wanatabe Angelfish is picky about its water and prefers acidic habitats. As a result, we recommend keeping the pH level between 8.1 and 8.4.

Water Hardness

Since Wanatabe Angelfish come from soft water, they prefer similar conditions in captivity.

We recommend maintaining the water hardness between 8 and 12 dkH to provide the optimal environment for your fish.

Ammonia, Nitrite & Nitrate

Ammonia and nitrite are poisonous to any marine fish and should be kept at 0 ppm.

On the other hand, nitrate is less harmful, but if it builds up in the soil, it can cause issues. We recommend keeping your nitrate levels as low as possible (below 20 ppm).

Water Movement

Watanabe Angelfish prefers strong water movements, so we recommend using a powerhead to create a moderate to strong water flow in your aquarium.

Specific gravity

The optimum salt concentration is 1.020-1.025, which corresponds to a salinity level of 14-15 ppts.

2. Tank Setup

Tank Size

Genicanthus are open water swimmers that require a lot of accessible swimming areas.

A 125 gallon or larger aquarium is necessary for a single full-grown Genicanthus.

Filtration & Aeration

The Watanabe Angelfish is well known for being very sensitive to water quality and parameters.

We recommend using a solid filtration system of high quality. There are many options, such as a canister filter, a sump filter, or an over-the-back filter.

Choose the one that fits better your aquarium size and needs.

Tank Lids

This species has been observed leaping out of open aquariums, so it is necessary to have a secure lid on your tank.

Hiding Places

The tank should include a variety of hiding places and live rocks for grazing.

A range of hard and soft corals and plenty of mature algae-covered live rock arranged into caves, overhangs, and crevices will be great for them to graze on and hide among.


These species prefer a dimly lit tank that resembles their deepwater habitat and helps them with the acclimation process.

Is Watanabe Angelfish Hardy?

The Watanabe angelfish is presently being cultivated in captivity. However, they are pelagic spawners that are difficult to breed in an aquarium.

Watanabe Angelfish Diet

Watanabe practically feed on planktivores, small crustaceans, and algae in their natural habitat.

They are simple to start within an aquarium and readily take in almost everything floating in the water column.

This is because their teeth and jaws are designed for capturing floating food particles rather than removing algae or coralline growth.

Aside from eating a lot of live rocks, they require a varied diet that is high in animal protein, such as:

  • Mysis shrimp
  • Marine plankton
  • Vitamin-enriched brine shrimp
  • Finely chopped crustaceans
  • Spirulina
  • Marine algae

Remember not to overfeed them as they may become obese and shorten their lifespan.

The best approach is to feed them three times a day but only give them what they can eat in 3 minutes.

Watanabe Angelfish compatibility

The Watanabe Angelfish is a non-aggressive and peaceful fish that cohabits with other aquarium angels.

Although they are tolerant of other angelfish species, it is ideal for keeping them in an aquarium with no other angelfish that are too similar to the Watanabei’s angelfish to avoid becoming territorial.

They love to be kept in groups of one male and several females if the tank is big enough.

Also, it is recommended to introduce them to the tank before other angelfish that may or may not get along with them.

Other peaceful, non-threatening tankmates for the Watanabe angelfish include:

  • Snowflake Clownfish
  • Small wrasses
  • Anthias
  • Gobies
  • Chromis
  • Blennies
  • Scarlet Cleaner Shrimp

Is Watanabe Angelfish Reef Safe?

The Watanabe Angelfish are best kept as a male-female pair in a spacious tank, and they make excellent candidates for a deepwater reef aquarium.

They are unlikely to harm soft and hard corals (including stony corals), typically reef safe.

Last Words

As you can see, Watanabe angelfish is a beautiful and peaceful fish that deserves a place in any saltwater aquarium.

Watanabe’s angelfish is an excellent reef aquarium candidate as they are non-aggressive and largely ignore sessile invertebrates.

These fish will add a splash of beauty and excitement to your aquarium with their unique coloration!

We hope that you enjoyed reading this as much as we did. If you have any questions, feel free to leave a comment below!