Masked Swallowtail Angelfish

The Masked Swallowtail Angelfish, Male (Genicanthus semifasciatus) is a peaceful species that is reef-safe, admired for its striking swallowtail shape, bold sexual dimorphism, unique coloration, and graceful swimming behavior.

Males typically display a grayish to whitish body with bold vertical black striping and the characteristic swallowtail fin, while females/juveniles show a more subdued yellowish to silvery body with less dramatic markings.

They reach about 8 inches in adulthood and should be housed in aquariums of at least 125 gallons. Provide ample live rock for grazing, open swimming space, and hiding spots, along with stable water parameters (salinity ~1.020–1.025, temp ~72–79°F, pH ~8.1–8.4). A secure lid is essential, as these angelfish are known jumpers.

Diet should consist of a variety of foods including mysis shrimp, enriched brine shrimp, copepods, high-quality marine pellets, and marine algae. With proper care, this angelfish makes a standout and active addition to a reef or fish-only system.

International Aquatics Quarantine & Guarantee: All fish are checked by marine vets, given a formalin bath, and held for 14 days in copper-treated systems. We feed Selcon-soaked food with Kanaplex and Metroplex during quarantine. Unless marked, all livestock comes with our 15-Day Guarantee. You will receive a video of your fish eating before shipment. On request, we also send photos/videos after arrival at IA. Some species are import-to-order (3-10 business days). Many common species are already cleared or near the end of QT.

Several species will be import-to-order and may take anywhere from 3-10 business days to secure. Once your fish is secured, you will be notified, and the quarantine process will then begin.