Masked Swallowtail Angelfish

Genicanthus semifasciatus


(2 Reviews)

Masked Swallowtail Angelfish
Dive into elegance with the Masked Swallowtail Angelfish, showcasing distinct differences between male and female colors. Easy to care for, its peaceful nature and striking patterns make it a captivating addition to any saltwater aquarium.

Masked Swallowtail Angelfish

Genicanthus semifasciatus


(2 Reviews)

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Masked Swallowtail Angelfish Care Facts

Care Level: Moderate
Temperament: Peaceful
Diet: Omnivore
Reef Safe: Yes
Minimum Tank Size: 120 gallons
Max Size: 8 inches
Very few fish show sexual dimorphism, out of those few the Masked Swallowtail Angelfish, Genicanthus semifasciatus, is one of them. Females will display a creamy white color bottom half that fades to yellow towards the top half with a black band just above the eye and on the tail. Males will display more of a yellow/orange color beginning at the face and along the body with black vertical striping. Since they are more peaceful than many other Angelfish, they can be kept as a mated pair, or in a small school of females. Avoid keeping two males in the same tank, as it can lead to extreme aggression.

These Angelfish are also unique in the way that they are reef safe, and will not nip at soft and stony corals, or sessile invertebrates, making them a great choice for an Angelfish in a reef tank setting. Diet should include a variety of spirulina, marine algae, high quality angelfish preparations, mysis and brine shrimp, 3 times daily.



Masked Swallowtail Angelfish (Genicanthus semifasciatus) for Saltwater Aquariums

The Masked Swallowtail Angelfish, scientifically known as Genicanthus semifasciatus, is a captivating marine species suitable for saltwater aquarium enthusiasts. Known for its unique appearance and moderate care requirements, this angelfish species offers a distinctive aquatic companion for your marine setup.

Habitat of Masked Swallowtail Angelfish:

Masked Swallowtail Angelfish are native to the warm waters of the Indo-Pacific Ocean. They dwell among coral reefs and rocky outcrops in their natural habitat, often hiding in crevices and caves.

Reef Compatibility with Masked Swallowtail Angelfish:

This species is considered reef-safe, as it does not typically harm or disturb corals or other reef invertebrates. However, individual behavior can vary, so cautious observation is recommended when introducing them to a reef tank.

Size and Lifespan of Masked Swallowtail Angelfish:

In captivity, Masked Swallowtail Angelfish typically reach a length of around 6 to 8 inches (15 to 20 centimeters) at maturity. They can live for an average of 10 to 15 years with proper care, making them a long-term addition to your aquarium.

Diet in Captivity for Masked Swallowtail Angelfish:

Maintaining the health and vibrancy of your Masked Swallowtail Angelfish involves providing a well-balanced diet. They are omnivorous and thrive on a diet including high-quality marine pellets, flake foods, and various frozen offerings such as brine, mysis, and spirulina.

Aquaculture Availability of Masked Swallowtail Angelfish:

Masked Swallowtail Angelfish are not available through aquaculture. Most specimens available to hobbyists were sourced from the wild.

Compatibility with Other Fish and Invertebrates for Masked Swallowtail Angelfish:

Masked Swallowtail Angelfish are generally peaceful and can coexist with other marine species. Compatible tankmates include:

  • Firefish Goby (Nemateleotris magnifica): These colorful gobies are known for their peaceful nature and can share an aquarium with Masked Swallowtail Angelfish.
  • Royal Gramma (Gramma loreto): Royal Grammas are relatively small and non-aggressive, making them suitable companions.
  • Six Line Wrasse (Pseudocheilinus hexataenia): Six Line Wrasses are active swimmers and can coexist peacefully with Masked Swallowtail Angelfish.
  • Clownfish (Amphiprioninae): Various clownfish species, known for their gentle nature, can be compatible tank mates.
  • Purple Firefish (Nemateleotris decora): These fish add striking colors to your aquarium and are known for their peaceful disposition.

Sexual Dimorphism in Masked Swallowtail Angelfish:

Masked Swallowtail Angelfish do not exhibit significant sexual dimorphism, making it challenging to distinguish males from females based on physical characteristics alone.

Juvenile to Adult Coloration Changes in Masked Swallowtail Angelfish:

Juvenile Masked Swallowtail Angelfish showcase a unique coloration, featuring a striking pattern of black bars and a masked facial appearance, which gives them their name. As they mature, these colors become less pronounced, and adult specimens typically display a subdued blue-black body with a masked face, making them visually distinctive and appealing.

Temperament of Masked Swallowtail Angelfish:

Masked Swallowtail Angelfish are known for their generally peaceful temperament. However, like many angelfish species, they may become territorial as they mature. Ensuring sufficient hiding spots and space in the aquarium can help mitigate potential aggression.

Tank Requirements for Masked Swallowtail Angelfish:

To provide an ideal environment for your Masked Swallowtail Angelfish, consider the following tank requirements:

  • Minimum Aquarium Size: A tank with a capacity of at least 120 gallons is recommended to accommodate their size and swimming habits.
  • Water Conditions:
    • pH: Maintain a stable pH level between 8.1 and 8.4.
    • Salinity: Keep the salinity in the range of 1.020 to 1.025.
    • Water Temperature: Maintain the water temperature within the range of 75-82°F (24-28°C).
    • Water Flow: Moderate water flow is suitable to mimic their natural habitat.

Common Names for Masked Swallowtail Angelfish:

The Masked Swallowtail Angelfish is also known as the Half-Black Angelfish.

Why Choose Saltwaterfish.com for Masked Swallowtail Angelfish:

When considering where to purchase your Masked Swallowtail Angelfish, Saltwaterfish.com offers several advantages:

  • Wide Selection: Saltwaterfish.com provides a diverse range of marine fish, including the Masked Swallowtail Angelfish, ensuring you can find the perfect addition to your aquarium.
  • Quality Assurance: They prioritize sourcing healthy and vibrant specimens to give your new aquatic companion the best start.
  • Expertise: With decades of experience shipping your favorite marine life, Saltwaterfish.com is the most trusted source for all your aquarium needs.

In conclusion, with its unique appearance and moderate care requirements, the Masked Swallowtail Angelfish can be a captivating addition to your saltwater aquarium. By providing the appropriate habitat, tankmates, and diet, you can enjoy the distinctive beauty of this species while ensuring its well-being and longevity in your care. Consider Saltwaterfish.com as your trusted source for acquiring a Masked Swallowtail Angelfish to enhance your marine aquarium experience.

I love this Masked Swallowtail Angelfish ! Pictures don’t compare to the live fish. The new addition improves my saltwater water aquarium. Everyone loves it.


Reviewed by: Joe Welsch on June 2, 2022

This is a great Masked Swallowtail Angelfish who showed up healthy and happy. He was shy at first in my quarantine tank but after moving him over to the main tank he has been quite the showman. Beautiful fish to add to a reef tank.


Reviewed by: James Thompson on May 2, 2022

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