Female Spotbreast Swallowtail Angel (Genicanthus Melanospilos)

Also Known As: Female Blackspot Swallowtail Angelfish

Compatibility and Behavior
The female Spotbreast Swallowtail Angel is one of the most elegant and versatile Angelfish species in the trade. The dorsal half of the body is yellow, the underside is a soft bluish-white, and the forked swallowtail caudal fin is pale blue with bold black edging along the upper and lower lobes. The streamlined body, long tail streamers, and habit of hovering constantly in mid-water give it an anthias-like presence that feels different from the heavier, rock-picking demeanor of most larger angels.

Females tend to stay smaller than males and are generally less assertive, making them solid candidates for peaceful to moderately active community and reef tanks. This species is haremic by nature. In the wild they live in groups with one dominant male and multiple females, and in captivity a single female, a bonded pair, or a harem in a sufficiently large system can all work well when introduced together.

What makes a harem of Swallowtail Angels in an aquarium? In a sufficiently large tank (at least 180 gallons), a harem can consist of 1 male with 2-4 females. Since they are hermaphrodites (meaning a female can change into male), if you start with a small group of females (3-5 specimens in a big system), typically the largest, most dominant one will change into a male, while the others remain females, forming a natural harem.

On the reef safety front, Genicanthus angels including the Swallowtail are about as reef-safe as angelfish get. Their diet in nature is dominated by zooplankton captured in the water column rather than coral or clam grazing, and the female Spotbreast reflects that. Problematic coral nipping is uncommon compared to most other angel genera, though occasional exploratory pecks at rock surfaces are always possible. They can be mildly competitive with very small, delicate planktivores like anthias, but generally mix well in reef communities when given adequate open water.

Aquarium Requirements
Female Spotbreast Swallowtail Angels need room to move. A 90 gallon tank is the minimum for a small-medium single female, with 120+ gallons being recommended for longevity. A 180+ gallon tank is recommended for harems or for mixing multiple Genicanthus species.
The aquascape should provide tall rock structures and ledges for retreating, but the overall layout should prioritize open mid-water swimming lanes rather than dense, cluttered rockwork. Moderate to strong, well-oxygenated flow suits them well and keeps food suspended in the water column where they prefer to feed. Strong biological filtration and efficient protein skimming are important given the frequent feeding schedule these constant planktivores require. Feed small and often, with a varied diet of mysis, finely chopped shrimp, copepod-based blends, enriched brine, and quality marine pellets. Scattering food into the flow so they can pick items out of the water column as they would naturally is a nice touch that keeps them active and engaged.

Specifications
Approximate Size: Sm: 2–2.5", Md: 2.5–3.5", Lg: 3.5–4.5"
Diet: Planktivorous omnivore; mysis, enriched brine, finely chopped seafood, copepod blends, quality marine pellets
Origin: Indo-West Pacific, including Japan, Indonesia, and western Pacific reef slopes
Care Level: Moderate
Reef Safe: Yes; among the most reliably reef-safe angelfish
Temperament: Generally peaceful; may lightly compete with smaller planktivores but mixes well with similar or larger community fish
Minimum Tank Size: 90 gal minimum for a small specimen, 120+ gallons recommended in general, 180+ gallons for a harem
Special Considerations: Requires open swimming space and frequent small feedings; does best in mature, stable reef systems with good flow