Japanese Swallowtail Angelfish (Female)
Scientific Name: Genicanthus melanospilos
Also Known As: Spotbreast Angelfish, Blackspot Angelfish, Blackspot Lyretail Angelfish
Care Level: Expert
Temperament: Peaceful
Diet: Omnivore / Zooplanktivore
Reef Safe: Yes
Minimum Aquarium Size: Approx. 475L+
Maximum Size: Approx. 18cm
Origin: Indo-Pacific
The Female Japanese Swallowtail Angelfish (Genicanthus melanospilos) is a beautiful and relatively peaceful marine angelfish, particularly sought after by reef keepers because it is considered one of the safer angelfish choices for coral-filled aquariums.
Females are easily recognised by their attractive two-tone colouration, with a yellow dorsal region transitioning into pale blue across the lower body, complemented by a striking blue tail with darker edging.
Aquarium Care
Japanese Swallowtail Angelfish require a large, mature marine aquarium with excellent water quality, plenty of swimming space and substantial live rock.
Although they appreciate rockwork for shelter, they are active open-water swimmers and should not be kept in an overly cramped or heavily obstructed aquarium.
They are generally peaceful compared with many other angelfish and can work particularly well in larger community reef systems with compatible tankmates.
Japanese Swallowtails can also be kept as a male and female pair, or potentially in a small group where sufficient aquarium space is available.
Reef Compatibility
One of the biggest advantages of the Japanese Swallowtail Angelfish is its suitability for reef aquariums.
Unlike many traditional angelfish species, members of the Genicanthus genus naturally feed heavily from the water column rather than grazing directly on corals.
As a result, they are generally considered reef safe and unlikely to nip at stony or soft corals, making them an excellent option for larger reef systems.
Feeding
Japanese Swallowtail Angelfish are primarily zooplanktivores and should receive a varied, nutritious diet.
Suitable foods include:
Regular feeding of a varied diet is particularly important for maintaining strong condition and vibrant colouration.
Female Colouration
Japanese Swallowtail Angelfish display strong sexual dimorphism, meaning males and females look distinctly different.
Females generally have a yellow upper body fading into pale blue below, while mature males develop a lighter body with prominent reddish vertical striping.
This makes a male and female pair particularly impressive in a large reef display.
Why We Like Them
The Japanese Swallowtail is one of the best options for reef keepers wanting a true angelfish without the usual concern of coral nipping.
The female's combination of yellow and blue colouration is elegant rather than overly flashy, while their active swimming behaviour makes them an impressive feature fish in a large marine aquarium.
They're not a beginner species and deserve a large, mature, stable system, but in the right aquarium they're an outstanding reef angelfish.
